Disaster Recovery

Maximize the performance of Microsoft Vista and Intel Matrix RAID

If ever there was a black art in the world of IT, RAID certainly fits the bill. Alan Norton details some RAID performance issues and describes how to maximize Vista's performance when using RAID.

If ever there was a black art in the world of IT, RAID certainly fits the bill. In this document, I detail some RAID performance issues and describe how to maximize Vista's performance when using RAID. I also do some real-world testing to see just exactly what you can expect when implementing RAID on a desktop PC. The results I find and the conclusions I make may surprise you.

Overview

I have been interested in RAID for several years now. It was late summer 2006 when I purchased two 250GB Maxtor SATA drives to be used in a RAID array. I have since learned from real-world experience the pros and cons of RAID 0, RAID 1, RAID 5, and Intel® Matrix RAID.

I read with interest the written banter between George Ou and Robin Harris over at CNET in the summer of 2007. They were debating the data redundancy merits of RAID on desktop PCs. I want to look at the RAID issue from a different angle -- using RAID primarily for speed and not data redundancy.

I will be discussing RAID and Windows Vista on a desktop PC, though the concepts apply to all versions of Windows from Windows 2000 on (for the purists out there -- NT 4.0 Workstation supports RAID 0). The RAID capabilities discussed in this article pertain specifically to Intel® Matrix RAID.

If you decide that RAID belongs on your desktop PC, then the most important considerations are which RAID level or levels to implement and which RAID level is best for the operating system. Exactly how you implement RAID will have a big impact on the final performance of the RAID array and Windows Vista.

I won't go into RAID basics in this blog post, but if you want more information about RAID, please read "What Is RAID? Some RAID Basics."

Note: I have taken great care to verify the accuracy of the information in this article, but RAID is complicated. If you find an error, please report it in the forum.

This is the first of a two-part series. This blog post is also available in PDF format in a free TechRepublic download.

The need for speed

What is the single best way to improve your Windows Vista systems performance? If you have one GB of system memory, then the answer would be to add more memory. If, however, you already have two or more gigabytes of system memory, then the answer is to tackle the next likely bottleneck in your system. And that bottleneck is your hard disk drive.

You could go with a 10,000 RPM hard disk drive like the Western Digital VelociRaptor or a Solid-State Drive (SSD). Both offer faster performance -- at the price of lower capacity and higher cost. There is another option thanks to the wide availability of motherboards supporting Intel Matrix RAID. Intel Matrix RAID offers improved performance and the option of data redundancy as a bonus. In case you were wondering, you can use 10,000 RPM drives and SSDs in a RAID array with the caveat that, as of the fall of 2009, SSDs can be problematic and very expensive.

Performance testing

I have read information on the Internet that claims that a two-drive RAID 0 volume is nearly twice as fast as a single drive. I have also read that the performance benefits of RAID 0 striping are a myth. I wanted to do some testing to get some real-world results. The tests were run with and without volume write-back cache enabled so let me take a moment to explain what volume write-back cache is and how it can improve RAID performance before we get to the test results.

Volume write-back cache

One feature of Intel Matrix RAID that can improve performance is volume write-back cache (VWBC). Don't confuse volume write-back cache with hard drive data cache (see definition below).

Volume write-back cache uses system memory in a similar way that disk cache is used on a hard drive. Data throughput is improved by temporarily storing frequently used data sectors in system memory. Volume write-back cache can improve write speeds, especially on a RAID 5 array. It can, however, lead to data loss or corruption due to an improper shutdown of the system.

It is best to have a good UPS if you want to turn volume write-back cache on for any RAID level with data fault tolerance. If your computer is connected to a UPS and a power outage occurs, VWBC is automatically and temporarily disabled.

Volume write-back cache can be disabled or enabled for each RAID volume (Figure A).

Figure A

Right-click the volume and then click Enable Volume Write-Back Cache in the Intel Matrix Storage Manager Console to turn on volume write-back cache.

Intel Matrix RAID also uses a coalescer that combines write requests. The coalescer is enabled by default and cannot be turned off.

Performance testing procedures

The tables below show the percentage gains or losses in performance for four different RAID levels as compared to a single drive.

  • Table A shows the performance gains or losses with volume write-back cache disabled.
  • Table B shows the same tests with volume write-back cache enabled.
  • Table C shows the changes in performance, positive or negative, when volume write-back cache is enabled.

The tests were done with Windows Vista Ultimate x64 SP2 running on a single drive, a two-drive RAID 0 volume, a two-drive RAID 1 volume, a three-drive RAID 0 volume, and a three-drive RAID 5 volume. Five different system utilities were run in seven different tests using an application I wrote to launch and time each process. Each system utility reads from and writes to files on the RAID level being tested.

Stripe sizes of 128KB for RAID 0 and 64KB for RAID 5 were used. The times recorded for the single drive test are used as a baseline to calculate the percentage gains or losses.

Each Vista installation included the following applications -- Intel Matrix Storage Manager, avast! Anti-virus and definition updates through 5-21-2009, the Windows Automated Installation Kit and my Script Builder and Timer app. The drivers and control panels were installed for the nVIDIA graphics card and the Realtek on-board HD audio. Drivers were installed for the monitor.

All tests were performed on the following system:

  • Foxconn x48 ICH9R BlackOps motherboard
  • Intel Core 2 Quad Q9650 3.0GHz CPU
  • 2 x 1GB Corsair TWIN3X2048-1333C9 1333MHz DIMMs
  • 3 x Samsung Spinpoint F1 HD753LJ 750GB SATA II 7200 RPM 32MB hard drives
  • CORSAIR CMPSU-400CX 400 Watt power supply
  • Samsung SH-S202G PATA WriteMaster 20X DVD burner
  • eVGA 256-P2-N549-TR Geforce 7600GS 256MB GDDR2 PCI Express x16 video card

Times will vary widely from system to system. Use the times provided in the tables as a guide to compare relative times between different RAID levels.

Table A

Percentage gains or losses for four RAID levels as compared to a single drive. Volume write-back cache disabled.

Table B

Percentage gains or losses for four RAID levels as compared to a single drive. Volume write-back cache enabled.
Conclusions
  • All tasks run faster on a RAID 0 volume.
  • Performance gains exceeding 10% are typical for RAID 0.
  • Performance losses exceeding 10% are possible for RAID 1 and RAID 5.

Table C

Percentage gains or losses when turning on volume write-back cache.

Turning on volume write-back cache should, in theory, improve performance. Table C shows poorer performance for some processes except for those running on RAID 5. Don't be misled by the cells for RAID 5; enabling VWBC did improve performance of the RAID 5 volume, but Table B shows that four of the seven test processes still took longer to perform than on a single drive.

Conclusions
  • Using volume write-back cache on a RAID 0 volume can actually decrease performance.
  • Volume write-back cache can have a significant positive impact on performance for RAID 1.
  • Volume write-back cache has the most significant positive impact on performance for RAID 5.
  • Use volume write-back cache with care. An improper shutdown is more likely to cause data corruption, and volume write-back cache can cause poorer performance.

Please note that the mix of tasks that you perform on a daily basis will determine your performance gains or losses. The imagex test results are a good combination of read/write requests and intensive CPU usage.  The xcopy and oscdimg test results are best to use if you do a lot of read/write processing. The format test results provide a good expectation of the performance gains or losses you should see for tasks that do a lot of write-only requests to the RAID volume. If you do a lot of read-only tasks, place more weight on the results from the findstr test.

I performed four series of tests. During the first series of tests I measured the Vista Ultimate X64 SP2 installation and startup times. I found that installation times were a surprisingly consistent 24 minutes for all but RAID 5. Installing Vista to a RAID 5 volume took 31 minutes. The differences in startup times, from power on to clock showing on desktop, were negligible for all RAID levels.

Best stripe size for performance

Stripe size can have an impact on performance. The best stripe size for performance is typically smaller stripe sizes when working with large files. Desktop PC users perform a wide range of task, and those tasks can change over time so there really is no best stripe size.

The problem in choosing the optimal stripe size is that the stripe size is set when the RAID volume is created and cannot be changed. Unless you have a lot of spare time on your hands, there is no easy way to experiment with different stripe sizes.

The best option for desktop use is to simply accept the default stripe choices. For RAID 0 the default is 128KB and for RAID 5 the default value is 64KB.

RAID 1 does not use striping so you won't have to set a stripe size.

Other factors that influence performance

There are a number of technologies that have been developed to improve data throughput to and from disk drives. As engineers sometimes want to do, they have used an alphabet soup of acronyms to name these technologies.

  • S.M.A.R.T.: S.M.A.R.T. stands for Self-Monitoring, Analysis and Reporting Technology. It is used on hard drives to report the drive health and status. Any data errors that occur on a hard drive with S.M.A.R.T. are stored and reported by utilities that can read the S.M.A.R.T. information. When running Intel Matrix RAID, the S.M.A.R.T. information for RAID array member drives is unavailable to the OS or utilities that can read the S.M.A.R.T. information. The Intel Matrix RAID controller, however, can and does read the S.M.A.R.T. data. If a S.M.A.R.T. error event is reported to the controller, the user will be notified that a S.M.A.R.T. event has occurred.
  • Hard Disk Buffer or Cache: Hard drives have on-board memory, typically 8MB to 32MB that is used to cache data as it is written to the disk. This memory buffer improves data throughput but can cause data corruption if a BSOD or improper shutdown occurs before the data can be flushed from the memory and written to the disk (Figure B).

Figure B

Right-click on the RAID array volume in the Device Manager under Disk Drives and select Properties and the Policies tab to disable or enable hard disk write caching. The write caching will be enabled or disabled for all RAID array member drives.
  • NCQ: NCQ or Native Command Queuing improves data throughput by reordering up to 32 read/write requests to the drive. While transparent to and independent from the RAID controller, I include NCQ here because it can improve overall RAID performance (Figure C).

Figure C

The Intel Matrix Storage Manager Console showing Native Command Queuing Support and Hard Drive Data Cache Enabled with statuses of Yes or enabled.
  • TLER, ERC, and CCTL: TLER -- Time-Limited Error Recovery, Western Digital; ERC -- Error Recovery Control, Seagate; and CCTL -- Command Completion Time Limit, Samsung and Hitachi

TLER, ERC, and CCTL allow for better data error handling between the disk drive and the RAID controller. Turning this feature on allows a drive to complete the data error recovery process before the RAID controller can drop it from the RAID array.

Seagate's ERC is available only on the Barracuda ES and ES.2 SATA enterprise drives.

While this technology can be beneficial on a hard drive running in a server, its merits on a desktop PC are questionable. It is not necessary when running Intel Matrix RAID since a member drive will not be dropped from the array if a S.M.A.R.T. event occurs.

Which RAID level is best for Windows Vista?

The operating system is at the heart of every activity performed on a PC. Which RAID level you choose to install the OS on can have a significant impact on system performance.

If you are running Windows Vista and you pay any attention at all to the LED showing disk activity you will know that the disk drives are often busy when the system is idle. Ideally you want all that background disk activity to complete as quickly as possible if only to reduce the amount of work the member drives have to perform.

Windows Vista on RAID 0

Clearly, RAID 0 is the right place for Windows Vista if you are looking for maximum performance, but what about a drive failure? Isn't it better to install Windows on a RAID 1 volume where the data wouldn't be lost when a drive fails?

When you get right down to it, there is not much data in a typical Windows installation that you cannot easily replace or reconfigure. There is a relatively short list (Table D) of what will be lost if a Windows reinstall is necessary due to a drive failure.

Table D

E-mails you might receive in Windows Mail or your e-mail reader of choice E-mails can be routinely exported to a RAID 1 volume. You should already have a standard backup routine. That shouldn't change if you implement RAID. Copies of e-mails should exist as part of a routine backup plan.
Downloaded files, images, videos, music, etc. that may have been saved to a personal user folder Downloaded files, pictures, or any other user specific data should also exist on the backup. You can change the destination folder for applications that save files to the user's default folders or you can move the downloaded files, pictures, etc. to the RAID 1 volume after the download completes.
Unique and important data collected and stored by an application Most applications can be installed on a RAID 0 volume. You can change the destination folder for applications that store important data or you can install these applications on a RAID 1 volume.
Favorites or bookmarks you might have saved in your browser Bookmarks and favorites can be occasionally exported to a file on a RAID 1 volume and will exist on the backup.
Customized Windows settings Customized Windows settings can be restored fairly quickly.
Drivers and updates Drivers and updates can be easily downloaded and installed.

Personal information, Windows updates, and customizations will be lost when running Vista on a RAID 0 volume and a drive fails and what you can do to prevent data loss.

Thankfully, hard drive failures are not very common. You will likely have to reinstall Windows at least once before you experience the joys of a drive failure -- and that is the perfect time to find out just how good your backups really are.

If you do some planning in advance and are disciplined with your backups, you can successfully run Windows Vista on a RAID 0 volume without personal data loss.

Windows Vista on RAID 1

Intel recommends this solution. Roger Bradford from Intel has this to say:

"Our position on RAID 1 is around data protection and minimizing downtime for business environments and mainstream consumers who may not be willing to incur the downtime associated with a HDD failure and may not have the expertise or resources on hand to quickly get their systems back up and running. ... Ultimately we enable choice."

If you choose to install Windows on a RAID 1 volume you will have to accept slightly slower response times than a single drive. The biggest advantage of RAID 1 is that Windows Vista will still load after a single member drive failure.

However, if you want maximum performance, don't put the operating system on a RAID 1 volume.

Windows Vista on RAID 5

Windows Vista on a RAID 5 volume is a bad idea, especially if you are looking for improved performance.

I originally set out to write some scathing words about the use of RAID 5 on a desktop. After doing the failure testing and discovering that most recovery events require much less time than the time for a full rebuild, I have moderated my opinion a bit. I still don't think RAID 5 on a desktop PC is a good idea, but there are a few desktop users that can benefit from RAID 5 -- if they implement both RAID 0 and RAID 5, put the OS on the RAID 0 volume, and treat their new array with a little extra tender loving care. For example, treat your RAID 5 volume to a new UPS.

Roger Bradford recommends RAID 5 for the home multimedia center. "The HTPC environment is a good fit for RAID 5 in the desktop as they crave large amounts of storage and data protection."

For a full recounting of my RAID 5 misadventures and more information about why RAID 5 might be a bad idea on a desktop PC, please read "RAID 5 on a Desktop Computer Is Not Such a Good Idea!"

Windows Vista on Intel Matrix RAID

Almost everyone has important data that they can't afford to lose. The Intel Matrix RAID solution allows two RAID volumes on only two drives per RAID array. For best performance you should consider creating two RAID volumes, a striped RAID 0 volume for the OS and apps, and a mirrored RAID 1 volume for all your important data, e-mails, photos, music, documents, etc. A RAID 1 volume is the perfect complement to a RAID 0 volume.

The RAID levels performance scorecard

In summary, I have scored the four RAID levels based on performance in the scorecard shown in Table E.

Table E

Rankings from 1 (best) to 5 (worst) for the performance of the four RAID levels and a single drive with volume write-back cache disabled and volume write-back cache enabled.

The best explanation of the poor rankings for RAID 1 and RAID 5 is that data redundancy has a price, and that price is poor performance.

In the second part of this series, I discuss what happens to your RAID array when things go wrong and how this can have a big impact on performance.

Author's note

I want to thank Roger Bradford and Intel for their help and Intel Matrix RAID expertise and my parents for the gift that made the purchase of three new hard drives and RAID 5 possible.

TechRepublic's Windows Vista and Windows 7 Report newsletter, delivered every Friday, offers tips, news, and scuttlebutt on Vista and Windows 7, including a look at new features in the latest version of the Windows OS. Automatically sign up today!

About

Alan Norton began using PCs in 1981, when they were called microcomputers. He has worked at companies like Hughes Aircraft and CSC, where he developed client/server-based applications. Alan is currently semi-retired and starting a new career as a wri...

29 comments
maxoptimus
maxoptimus

I used both IMR and now RST without any problems. Also SMART can be monitored by latest smartmontools. And many people change ERC timing for old desktop drives (Seagate, WD and Sumsung). Looks like Seagate and WD lock this settings for new drives.

jaltone
jaltone

Back in the fall of 2005 I built this development workstation I'm using now with an Intel motherboard with Intel Matrix. I put in 4 hard disk drives of 200 GB each and put them all in a single RAID 5 volume. My workstation is plugged into an APC UPS unit. I've had my share of ups and downs with Intel Matrix RAID 5. First of all, I'd like to point out that the primary goal of a RAID 5 system is safety and reliability of whatever you have on it. Performance is only a secondary goal. Understand that the more hard disk drives you have in your workstation, the higher the probability that one of them will go bad sooner or later. And that's why RAID 5 was created, i.e., to increase reliability. As to my experience in the last 4 years, I can say that read times are definitely faster than if I hadn't had the RAID 5. But write times are indeed slower in Intel Matrix RAID 5 and I suspect that this is because of its hybrid hardware/software implementation. Overall it has been a good compromise over the years, I think. Reliability and performance are usually opposing goals, so one has to strike a balance between these two. You just need to find your own comfort zone. Lastly, I've found serious problems with Intel Matrix RAID 5. Every now and then it would mark one of my hard disk drives as bad. I would go through the usual steps of investigating it only to find that it's still good. So I go tell Intel Matrix that it's good, and then it does its slo-o-o-o-ow RAID 5 volume rebuild. This to me is the worst aspect of Intel Matrix RAID 5. If you Google this, you'll find that there are actually a lot of us who are experiencing this bad aspect of Intel Matrix RAID 5. I noticed that I am able to to work around this problem by turning off volume write caching. Yes, there is a big performance hit. It leaves a bad taste in my mouth. But I've not experienced this problem since I turned off volume write caching. My guess is that this problem is being caused by a bad Windows XP Professional OS not properly sending cache flush directives during shutdown. See http://support.microsoft.com/kb/332023 for details.

jakesty
jakesty

The Matrix raid depends on the CPU for processing. Raid 0 and Raid 1 don't have as much of a performance benefit as RAID 5 does when you use a dedicated controller with a processor to handle parity.

m.hodgett
m.hodgett

I think Alan missed a big point, that performance is greatly effected by the controller and whether it uses true hardware or software in hardware. RAID5 performance requires true hardware RAID, no doubt.

neil_willet
neil_willet

One item often ignored in drive performance discussions is Partition Alignment. Up to 20% or more. Until Server 2008 and Windows 7 Microsoft has Mis-Aligned ALL partitions when automatically created by the OS. Don't be fooled by the title of this Microsoft Article. Use this information and reap the rewards ! http://msdn.microsoft.com/en-us/library/dd758814.aspx This means that ALL drives (RAID & Non-RAID) can benefit from proper partition alignment. If you are serious about getting MAXIMUM performance from your drive/array, create the partition as a slave to an existing system or with a PE Boot CD or other technique before installing the OS. This problem has been fixed in Server 2008 and Windows 7. Any OS before that created the partition with improper alignment, thus causing performance degradation. Remember, practice safe computing - wear rubber gloves !

Justin James
Justin James

My desktop (running Vista) has two RAID 1 volumes. One for the OS/applications and one for the user data. I wanted the data redundancy, and I liked the idea that my data would be super-portable in the event of a total meltdown. First of all, I have to say that the RAID 1 is a lifesaver. I have drive failures once every 9 months, on average (and I'm using the high quality Western Digital RE drives!). The slight performance hit I take from it is more than offset by the efficiency I would lose if I had a drive failure on a single drive system every 9 months! That being said, splitting the system into two volumes didn't work out as well as I had hoped. I simply could not get all of C:\Users moved to the second volume cleanly (I've since learned how to get the whole thing moved nicely with mklink), so the user data is scattered between C:\Users and D:\Users. I didn't get the seperation I wanted. Also, I noticed that the performance gains I had hope for (in the event it needed to do a lot of system/program reads AND data reads at the same time) never materialized. For my next system, I am just going to have one large RAID 1 for the system and the user data, and a third drive as a single drive for backups and to put the swap file on (since that is the single most accessed file on the system). I think that should give me some major gains (and I'll turn on write back cache on that single disk). J.Ja

sammeow
sammeow

Hi, what do you think of RAID10?

BALTHOR
BALTHOR

You could stripe each platter in the drive unit.I see raid 0 as writing bytes to one drive then the other then back to the first.128kb to the first drive then 128kb to the second then back to the first.For some reason this increases the read/write performance of the computer.The computer is as fast as the file is read from the drive.If you decrease the stripe size then the number of bytes written to one drive is less before the switch to the second.

jhoffmaster
jhoffmaster

I'm running 2, 1 TB Western Digital Caviar Blacks in Stripe 0 in Vista 64 using the ICHR10 controller on my motherboard (fake raid). It runs Vista 64 great.

georgeou
georgeou

http://blogs.zdnet.com/Ou/?p=484 See my full report above. RAID 1 can give you twice the IOPS and it speeds up boot times and it gives you reliability whereas RAID0 is pretty reckless in terms of reliability. RAID 1 can also read two files (even large files) concurrently and run at twice the read throughput. I would disagree with your assertion that SSDs are problematic. They're expensive, but you could buy a small 32 GB drive for just the OS/App partition (excluding game installs of course) and then use a 1.5 TB hard drive for large files e.g., video content.

Alan Norton
Alan Norton

All comments and feedback welcome. I will be popping in occasionally to answer questions and respond when I can add to the discussion.

Mark W. Kaelin
Mark W. Kaelin

I have avoided using RAID on my desktop PCs because I believe it to be more trouble than it is worth. What do you think? Do you have a RAID array? Do you like? What benefit do you derive from it?

Alan Norton
Alan Norton

Thank you for sharing your RAID 5 experiences. Volume write-back cache benefits RAID 5 the most so it is a shame that you have to turn it off to keep the array stable. I am surprised to hear that you have a UPS and still had your share of problems. That is good information to know. I personally gave up on RAID 5. The long rebuild times were the deciding factor. I just don't ever want my hard drives working non-stop for 24 hours. I added one more drive and went with RAID 0 and RAID 10. Thanks again. That was a very informative post!

Alan Norton
Alan Norton

I discuss this in the article on my Web site: http://www.pecos-softwareworks.com/raid/what_is_raid_some_raid_basics.shtml I specifically excluded hardware RAID from the discussion because a good RAID controller card costs $300+ USD making it too expensive for most desktop users. Intel Matrix RAID and software RAID uses some CPU cycles and RAID 5 uses the most CPU cycles since it has to calculate the parity information. The CPU utilization is small, typically between 1% and 5% if I remember correctly, with the higher 5% number for RAID 5. The latest Intel Core 2 Duo or Core 2 Quad processors can easily handle the additional workload. This site claims that software RAID is faster than hardware RAID: http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/Deployment_Guide/s2-raid-software-raid.html This Web page also claims that cheap hardware RAID controller cards can be slower than software RAID: http://www.techarp.com/showarticle.aspx?artno=569&pgno=2 There are other problems with hardware RAID that make it a poor choice for everyone but the most extreme desktop PC enthusiast. Edit: fix link

Alan Norton
Alan Norton

Hi Neil, Interesting article. Under the section titled 'Partition Alignment in Windows Operating Systems', the article states that Windows Vista and Server 2008 usually performs partition alignment by default. Thanks for posting the link.

Alan Norton
Alan Norton

Hi Justin, Thanks for sharing what you have learned. RAID 1 has been a lifesaver for me as well. I lost a drive without losing any data. I can't even imagine using a PC without data redundancy now that I have experienced the benefits of RAID 1. I can understand your reasons for putting the OS/Apps on the RAID 1 volume. I expect this is the same for the majority of users but I think that there is a small class of users like me who want the fastest configuration for the OS that they can afford. I have reinstalling Windows down to a science. I have done it so many times. :-) I have a Vista Ultimate x64 install disc with SP1 and SP2 integrated so I can get the OS and latest service packs reloaded in 24 minutes. It then takes about one hour to reinstall my apps, load drivers, and personalize Vista. Have you considered a RAID 0 and RAID 1 configuration? Files that you can afford to lose can be stored on the RAID 0 volume and get you the performance gains you are looking for. I have more comments to make but much of what I have to say is addressed in the second article in the series. Hint - I like your idea of a third drive, partly for the reasons you list plus one more reason that I detail in the second article.

Alan Norton
Alan Norton

Hi, I haven't tried RAID 10 so I have no first-hand experience but I can give you some general thoughts. RAID 10 combines performance and data redundancy. All data is redundant. All data benefits from faster I/O, though not as fast as a four drive RAID 0 volume. There are a number of potential problems with four drives in a desktop PC. You will need a minimum of four drives for RAID 10 so there is the cost issue. Older motherboards like those with the ICH7R Southbridge chipset only supports 4 SATA I/II drives. That means you won't be able to add a SATA DVD burner or another SATA drive. Putting four drives in a desktop case can be an issue. Most mid tower cases I have seen have 4 or more 3.5 inch drive bays but check the specs. Personally, I would prefer putting that many drives in a full tower case. Hard drives can generate a surprising amount of heat. I have a mid tower case that has 120mm front and back fans and a 80mm side fan just for drive cooling but it is really noisy - to the point of being annoying. Each drive you add increases the likelihood of a drive failure. You need a power supply that can handle the additional drives. Unless you have a low-end PSU it shouldn't be an issue. Drives don't typically draw that much power for even the most demanding events (like spin up) but check the data sheet for the drive. Some drives use staggered spin up reducing the peak draw from the PSU. You will also need 4 SATA power cables from the PSU or some 4-pin molex to SATA adapters. You should get some really good performance from RAID 10 and still have fault tolerance. Now that you mention RAID 10 I am tempted to buy one more drive and test drive RAID 10 myself. I am not happy with the long rebuild times for RAID 5. Here are some articles you can read to learn more about RAID 10: http://blogs.zdnet.com/storage/?p=131 http://www.storagereview.com/guide2000/ref/hdd/perf/raid/levels/multLevel01.html

Alan Norton
Alan Norton

I wanted to do some real-world testing because burst speeds can be skewed by caching. My tests don't show that most tasks are faster in RAID 1 as compared to RAID 0. The testing I did with boot times was done manually from power-on to clock showing on the desktop. The times weren't all that different enough for me to include the test times in the article and a 10 second per day savings isn't significant. Also, I didn't trust the tests because they were done manually and included the time it takes to login to Windows. My comment about SSDs being problematic is based on what I have read in some forums and general info from the manufacturers and from reviews. I would like to have some first-hand experience with SSDs but they are out of my price range. I have read that some people are having problems with SSDs in RAID arrays. I read on an OCZ forum that writing a large number of small files files to an SSD can be extremely slow. I wouldn't be surprised if that is true if SSDs are anything at all like flash memory. I also read that SSDs are fast until the entire drive space has been written to once. The 'trim' feature in Windows 7 should help solve that but that doesn't solve anything in Vista and the article is about Windows Vista and Intel Matrix RAID. There is also the issue of wear-leveling sometimes solved by using only part of the available storage capacity of the SSD. All of those issues are what I would call problematic.

Aaron451
Aaron451

I have an Intel DX58SO MB with i7 processor. Originally used a single drive system, but when I installed Win7 switched to RAID0. My daily use shows a significant increase in performance. I work a lot with large files (>4 gig). Won't switch back!

jmhmaine
jmhmaine

I miss Intel's Matrix control. When I bought my last PC, Dell's XPS 720, it had an NVIDIA motherboard. That board comes with NVIDIA?s Storage software. I setup RAID 1 for my primary drive on two 320 GB 7200 drives. Performance has been sluggish compared to my older PC with the Intel setup. I did off load my data files to an External WD device that has RAID 1 setup (RAID 0 was the option) that is connected via an eSATA cable. The WD device is speedy, once it ?wakes-up? ? I don?t believe there is a setting telling it not to sleep. When Vista 7 is launched, I?m thinking about buying a new PC with two SSD in RAID 1. I cannot afford the downtime, but I want it to be zippy. I?ve heard go things about Intel?s X25 drives, so likely go with a pair for the OS. For the data drive I?m thinking about either RAID 10 or RAID 1 again with 1.5 GB drives.

Alan Norton
Alan Norton

I saw that Web site when I was doing the research for the article. I almost added a link to it. RAID 5 takes RAID complexity to a new level. RAID 10 is great if you can afford the drives. Thanks for the links.

Justin James
Justin James

I'm the opposite of you... I keep an OS installed until the hardware gets replaced. I'm running a copy of Vista that was installed within 24 hours of its original release on MSDN. That's nearly 3 years old, with only a mild hint of "bit rot" (namely, Windows Media Player won't start unless I do "Run as Administrator"). For me, it takes me 24 hours to have a system installed and running, and another week or so to get all of the apps set up the way I like them. Meanwhile, I get 200+ emails a day. I've found that if I go more than a day without a system, it takes me a *week* to catch up. So for me, doing the OS wipe/reinstall is *not* an option. I can replace the hardware and migrate, though (I've been saving my pennies to do this). I may note, Vista is the first Windows OS *ever* to not have me climbing the walls with "bit rot" after a year or so, I'm pretty impressed with it so far. And I've got this box loaded to the gills with development tools! J.Ja

Alan Norton
Alan Norton

Thanks Aaron. RAID 0 is ideal for working with large files. It would be interesting to poll how many people tried RAID and didn't like it. Like you I won't go back to a non-RAID system. You are aware of the additional risk to your data on RAID 0? Do you back up your files or move them to another drive after working with them?

Alan Norton
Alan Norton

Yes and if the motherboard dies you are stuck with buying another nVIDIA based motherboard or trying to find one you can borrow just to retrieve your data. I'll be discussing these issues in the second and final article in the series. I too have heard good things about Intel's X25 SSD drives - but the price. Ouch! Windows 7 is definitely the way to go if you want to run SSDs in your system - the 'trim' feature as an example: http://windows7center.com/windows-7-feature/windows-7-to-improve-on-solid-state-drive-ssd-performance/

Alan Norton
Alan Norton

Before building computers and writing tech articles I ran NT 4.0 Workstation for years (I think I was 5+ years) without a reinstall. I hadn't considered putting the pagefile on a separate drive. Thanks for bringing up the topic.

Alan Norton
Alan Norton

That's good to hear. I had to ask. You are right about hard drives. In the second article of this series, (http://blogs.techrepublic.com.com/window-on-windows/?p=1490), I discussed the failure of one of the member drives in my RAID array. I am replacing the refurbished, now defunct, hard drive I got stuck with, (long story - see http://pecos-softwareworks.com/a_case_of_maxtaken_identity.shtml#School), with two brand new Maxtor 500GB hard drives. No more 'open box' items for me. For $15 USD less each I can now get twice the capacity and a much faster drive. It didn't make sense to find another matching hard drive for a drive that is now more than three years old. The old drive will be used as a third non-RAID drive for backup and for temporarily installing Vista the next time a drive fails - hopefully three or more years from now.

Aaron451
Aaron451

I backup my personal files at least once a week. disk space is so cheap there's no excuse. I do believe there's a way to change the default storage location for user files but haven't gone that far - yet.

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