Discussion on:

How do I use a RAM disk to help speed up disk-intensive applications?

RAM disks used to be a common power user device for increasing performance; do you still use RAM disks for this purpose? What application do you recommend for RAM disks?

ramdisk.sys.

I use ramdisk all the time. When we edit audio with goldwave, we have wav files expanded in the ram disk. in this way, non-linear edits is very fast!. with regular disk (even raid0), the speed is very slow, even with coreI7 and new cpus.

I use ramdisk in rendering sets in truespace as well.

In 1990/91 I run AutoCAD 10 from RAMDrive. I run it the way what was later known as "DOS mode".

I copied WHOLE program to RAMDrive. It was around 3Mb. Yes, it was *three MEGs!* - complete design/draughting software which today Autodesk delivers on 1x DVD 32bit version and another DVD for 64bit to be installed.

It easily beat AutoCAD 10 DOS Extender version when it became available. And we compared 2 PCs:

- my 286 PC running at 11MHz (4Mb RAM, 3Mb used as RAMDrive; part of DOS and some drivers loaded HIGH, which is between 640 and 1024kb for those who are too young to know). I also run some *memory resident* programs: Sidekick, plot and print spooler (2 different queues!).

- competing machine was 16MHz 386 with the same 4Mb RAM "virgin", only AutoCAD and DOS with EMM (Expanded Memory Manager).

We timed opening the same drawing from the same floppy (1.2Mb, 5.25 inch).
Difference was around 25%. Editing the drawing (i.e. using various AutoCAD features) was much, much faster on my PC. Starting the program was much faster as well - obviousy copying it from Hard disk to RAMDrive I put in autoexec.bat ......

Today I use AutoCAD 2011 and AutoCAD Electrical 2011 on multicore, multi-GHz PC with 2x 22" screens, 5-button (+2 rollers) optical mouse, listen to the radio on the same PC etc. But I still cannot forget excitement and the pleasure of those days. Single 14" VGA screen didn't look bad; nobody had more! Cleaning mouse's ball didn't bother us either.

I have to try it again sometime...

32-bit OS (Vista), 4GB RAM. The OS can only address 3 GB. Will a 1GB RAMdisk use the part of RAM that the OS can't access? or will it take that GB out of the 3 that the OS is using, leaving only 2 for the OS?

Not. It's an architecture issue.

VSuite Ramdisk (Free, Server edition etc) does exactly that. Especially helpful in 32-bit systems. In the setup menu there's an option to "Use OS Invisible Memory" for 32-bit systems with non-addressable RAM, and you may use a large portion of that RAM in such a system with this RAM Disk application, both effective and smart to do, since it's sitting there non-utilized.

Personally all my systems here are 64-bit and don't have that issue, but it IS an option with VSuite Ramdisk, both free, and the various paid versions. so there you go!

Here's the URL of the company whose RAM disk software we use, that is VSuite Ramdisk from Romex software:

http://www.romexsoftware.com/en-us/vsuite-ramdisk/index.html

I have a PC OEM desktop with 24GB physical RAM and I have a grand total of 6 working RAM disks with the Server Edition of the program...most are non-volatile but two keys are a 10GB scratch disk for audio, video and PS work; 512MB Ramdisk for my Chrome browser is the 2nd Ramdisk that I use with the Image Option, where it's saved during restarts, shutdowns, etc to cache memory on my main RAID 0's HD space.

The application uses Dynamic RAM Allocation also, ie it's not addressed until used; the 10GB scratch disk is set up where I can actually write and read fastdata to it in NTFS format, with NTFS compression for indexing for example.

The Chrome browser Ramdisk, by comparison, also uses the Image directory option, is not SCSI but rather Direct I/O Disk in options, which is faster than the SCSI option but not recognized by Disk Management or any other storage utility, so you cannot use it like an SCSI non-Direct I/O Disk.

The SCSI Ramdisks we use with DDR3 RAM in a Core i7 environment have read and write speeds up in the 5,000MB/sec range (five thousand MB/sec!), which compares very favorably with normal read/write to disk speeds of 400-600MB/sec for our RAID 0 boot volume in this particular computer.

You can see where that is a huge advantage for work I mentioned above, on the 10GB scratch disk for example.

Since we started using the Ramdisk software my personal productivity is up perhaps about 25-40% overall on big I/O projects, and simple things like the Chrome browser action is very fast, web pages are rocket-like launching, recurring memory functions are also rapid.

Overall we are pleased with the software! (there's a 15-day trial period for the paid versions of the program where everything works 100%, and you can see where it benefits you or not.)

I haven't used a RAM disk in years, but back when I had a 286 with a whole megabyte of RAM, DOS could only use 640K. I don't recall what application I was using (probably RAMDISK.SYS), but it used the upper 360K for a RAM disk, which allowed me to move things around a lot faster. I haven't checked yet, but I'm sure there are applications that will do the same for today's hardware.

however, the truly unreachable RAM for the 32-bit Desktop Windows OS is above the 4GB line,

which is not necessarily a limitation for a 32-bit server OS starting with Server 2003 certain versions are capable of using much more RAM
see the MSDN article here:

http://msdn.microsoft.com/en-us/library/aa366778%28VS.85%29.aspx

SuperSpeed's RAMDisk and RAMDisk Plus will use the RAM above 4GB on a Desktop OS
- when you use RAMDisk Plus you can also shove the pagefile in the RAM above 4GB

It would be great if the software worked...

I used to use a RAM disk. I think I used Himem.sys in the config.sys file to set it up, but I forget the exact syntax.
. . and was that in Expanded or Extended memory?

use:
- a system with 8GB RAM
- a 32-bit OS
- stuff the pagefile in the upper 4GB of RAM using: Gavotte's RAMDisk or SuperSpeed's RAMDisk Plus

That's a great idea!

How well does it work? Obviously the pages will be stored in physical RAM, but the OS won't know that so will continue to have page faults and will happily swap things out of RAM to your page file to make space to fault the old page back in. Does this constant paging slow things down signifiantly, or does it run pretty similar to a 64-bit OS with 8GB RAM?

I've been thinking about this a bit. The setup looks good but does it not require a 64bit OS? The ramdisk utility is running through the OS's memory addressing isn't it? Or, does ramdisk somehow address and manage RAM chips beyond the 3.5'ish gigs a 32bit OS is physically able to see?

I do see how this would benefit 32bit apps on top of a 64bit OS though. Win64bit can see your 8 gig of ram but you have Photoshop32bit which itself can only make use of 3.5'ish gigs. Stick Photoshop's swap file on a ramdisk and now the 32bit Photoshop is addressing 3.5'ish of RAM with the rest in a swap file running at the speed of the ram.

I've personally got an 8 gig system with 4.5 gigs wasted when I boot over to WinXP for a bit of gaming so I'm honestly asking if I've missed something. I'd love break out of the 3.5 gig limit even if it was using a swapfile trick.

the RAMDisk program(s) does that

with Gavotte's and SuperSpeed's RAMDisk Plus you get to use "Un-managed RAM"

and the 4GB limitation in 32-bit Desktop OS is a programmed and hardware limitation

as PAE in certain versions / editions of 32-bit Server OSes on server boards can address and use 8GB - 128GB RAM

this capability was available as far back as win2000:
- Server 4GB
- Advanced Server 8GB
- Data Center Server 32GB

(even the 64-bit desktop editions have programmed limitations)

see MSDN article for limits:
http://msdn.microsoft.com/en-us/library/aa366778%28v=vs.85%29.aspx

cheers for that clarification. So Ramdisk actually addresses and manages the extended RAM beyond 32bit's 3.5.

This makes no sense at all to me. A page file gets used when there's no memory. By limiting the amount of memory an application has by having a ram disk you are increasing the chances of swapping to the pagefile.
If you have large memory needs, it's best to leave your system alone. Programs that perform a lot of HD access would make a lot of sense to use a ram disk.

If you have over 3.5 gigs of ram and 32bit WindowsXP/Vista/Win7 anything beyond that amount is extra RAM the 32bit OS can't make use of.

This ramdisk utility, on a 32bit Windows, is able to make use of that extra RAM above what the OS can see. It can turn the extra RAM into a "hard drive" until next reboot.

8.0 gigs RAM installed
3.5 gigs RAM visible to the 32bit OS
4.5 gigs RAM used as "hard drive R:\"

Since R:\ read/writes at the speed of ram instead of the much slower physical hard drives, placing your swap file here gives you 3.5 gigs RAM and 4.5 gigs Swap running at the same speed. "Swap" behaves like extended RAM instead of a cache file on slow storage.

Never really had enough RAM to use one with Windows already running.

But the configuration and diagnostic software I use at work uses RAM disks extensively, primarily because the register PCs don't have internal hard drives.

Does installing RAM disck create a new partition on the hard drive? If I uninstall at a later time will my disk space be restored?

RAM disk do have performance gain. Especially, the application must work with temp file, i.e. office (cache file), crystal report (generate report). But, in fact, the performance gain only valid if your OS don't use swap disk. Therefore, you must balance the ram disk against swap disk.

I had setup a ram disk as temp drive, performance gain is noticeable cause my XP installed with 4G ram but XP only use 3.2G. I reserve 1 G ram as temp as well as eclipse workspace.

A swap disk creates extra "ram" by borrowing hard drive space to "swap" out part of what is stored in ram. A ram disk creates extra hard drive by borrowing ram space to present as storage. The two provide different functions which are closer to a mirror of each other.

Since a swap disk is a blob of file on a hard drive and a ramdisk is a simulated hard drive using part of the system ram, you can host your swap file on your ram drive. I'm not sure what benefit there would be over simply using the full amount of ram as physical ram rather than swap ram on a ram hosted virtual drive.

I think I'd do what he did. XP only recognizes 3.2 GB, so I'd give up a couple hundred meg and configure a 1G RAM drive, then use that as the location for the swap file.

All the benefits of swap space without the wait for the hard drive.

I used it before. Though it speed things up quite a bit, but it has a serious flaw: scheduled windows backup will not be successful. A less serious flaw is, you must clear the temp folder or some programs, like a print spooler, will stop working due to "not enough memory".

Will this applicatiob eb suitable for Win Vista or 2007 running at 64bits?

How is this different/better than ReadyBoost ?

With ReadyBoost, the data has to pass through the drive controller and the USB hub, then leave the mainboard, and the maximum speed of the transfer is usually at USB 2.0 speeds.

With a RAM drive, data remains in memory and all data transfers at memory bus speed.

Some say ReadyBoost isn't that useful - gives you that "extra" memory but does it really improve things?

I added a 1GB SD card [which I configured with ReadyBoost] on my netbook which already has 2GB of RAM. I can't see any improvement. Maybe I needed a larger card.

Between RAM and the CPU things are stinking fast.

Between RAM and IDE/SATA, things are fast'ish.. but not stinking fast. This is your swap speed slow down; you get more memory but running at the speed of the storage not memory.

Between RAM and USB, thinks really slow down. Like 0.680Gps versus SATA at 3.0GPS.

I just don't see how ReadyBoost using USB bus speeds is any different from simply using a swap file on the SATA bus which would be over three times faster. I'm open to the idea that I'm not understanding something inbetween though.

Your 3.0 Gps is the data rate once the sector is found. But your disk has to first seek to the sector, which takes several millisecs each time. The USB has no seek time.

I'd still rather just use SSD on my 3 Gig SATA bus. I've never seen the same overall performance come out of usb attached storage even with the lesser seek time.

Cheers though. I thought it was the speed of the bus more than the seek times.

I see huge speed improvement in LOAD Speeds with software like Adobe Photoshop, Premiere etc when I have readyboost enabled with a 4Gb usb fast drive.

just run on the command line,

mount -t tmpfs -o size=2gb tmpfs /myramdisk

Note that the software mentioned in this blog is a release candidate. Seems Dataram is using people as guinea pigs. Should offer a stable version and optionally this RC. It's an RC - it's in the version number from their web site.

I don't think your system will speed up by using the RAM disk to store the temporary internet files.

If anything, moving the temp folder [or if possible, the swap file] into the RAM disk.

"If anything, moving the temp folder [or if possible, the swap file] into the RAM disk."

That doesn't make sense. If I have free RAM, I shouldn't put the swap file on a RAM disk, I should configure my computer to use RAM before swap file... a much better (and cheaper) choice on a Windows PC is "Ready Boost", which moves the swap file to a flash drive.

J.Ja

causes the PageFile to operate at the speed of RAM with no Disk subsystem I/O delays

... it still doesn't make sense. Look at it like this:

System RAM: 12 GB
Size of swap file: 4 GB
Total RAM used by applications: 11 GB

Now, if I am running like this, I should be using 11 GB of RAM, all in physical RAM. If I push the swap file to RAM disk, what happens? The system using 8 GB of physical RAM for apps, then goes to swap, and pushes it all... guess where... into RAM.

It's totally illogical.

If you want to force 100% of your RAM usage into physical RAM, the solution is simple. Disable swap file. Why have the system jump through the hoops and layers of putting a swap file on RAM disk? I guarantee you that pushing the swap file onto RAM disk will be slower than not using a RAM disk for it, and in terms of the total RAM available, it is *identical*.

J.Ja

an x86 32-bit windows desktop OS system won't use more than the first 3.xGB with the last part of it going to managing system devices etc.
leaving you with 8GB of un-managed RAM that can't be used for anything but a RAMDisk

disabling pagefile in a 32bit desktop OS doesn't always produce the desired result either, especially for huge apps using huge files

I run my XP 32 4GB RAM system with a 2GB pagefile and it always has at least a 40 - 50% VMem / pagefile allocation for system processes and apps.
ie.
if Mem Usage for any one process is 500MB, then VMem / pagefile usage is around 400 - 500MB

I've never had any decent level of success with setting:
"No PageFile / 0byte pagefile"

shutting if off makes the system crawl especially when editing huge 1.8GB 24-bit audio files

I've had better success with creating a pagefile at the very beginning of a second HDD than setting it to 0Bytes

I've heard that Windows is actually pretty good at managing the swap file. If you create a system managed swap on multiple drives; it'll use the apropriate drive/swap. I'm guessing this means it'll swap to D when your making heavy use of C for active files or it'll track which drive provides the best performance?

I believe it was an interview with the guys behind Sysinternals but it's a long while back now and the details are faint.

Agreed. I always set my swap file to system-managed. I've always considered "tweaking" the swap file to be stupid. If you're hitting the swap file a lot, don't "tweak" the thing that is an order of magnitude slower than your actual RAM. Get more RAM instead to make sure you never hit the swap file hard. My second thought on the matter is that some really smart person at Microsoft has spent a lot of time writing code to manage the swap file. Chances are they have thought of all sorts of things I haven't, and will therefore handle the swap file far better than any setup I come up with.

Anyway, I haven't seen the interview you refer to but it will no doubt be by Mark Russinovich. And if he says Windows is good at handling the swap file, you can take that as a fact.

I don't doubt that Microsoft can hire some of the smartest developers out there. In past though, it seems the quality of the developers work gets degraded by the OS design choices and general inter-office politics. Most of the time I'd consider if a tweak does refine something towards my uses or beyond the factory defaults.

I believe it was Mr Russonivich (sp?) long before MS bought Sysinternals and hired him on. He did state pretty clearly that one of the things Windows does far better than tweaked hard setting is swap management. If I can track down my PDF or the original URL I'll post it for those interested.