what is the performance reduction -32bit old to 64 bit new?

Win7 has a much higher system requirement than that of XP

just the same as 98SE requires way more hardware than win3.10 WFWG

win3.10 will run extremely fast on an 80486 100MHz, 32 MB RAM and a 100MB HDD
good luck getting 98SE to run under that same system
first you'd need to at least install a 1 or 2GB HDD before even starting to install

XP Disc = CD of 583 MB (611,530,726 bytes)

win7 Disc = DVD of 3.47 GB (3,733,776,520 bytes)

it's best to do comparisons in the same version
eg.
compare XP 32 and XP x64
compare Vista 32 and Vista x64
compare Win7 32 and Win7 x64

generally you'll find that x64 has slightly higher hardware requirements

edit:
add info:

The 2009 version of this unit:
http://www.dell.com/us/dfb/p/precision-t7400/pd

handles XP x64 really well
but cost 5x what an XP-32 system would have at the time

If you go back to a 32 Bit OS you'll not even use all of the installed RAM. Any 32 Bit OS is only capable of reading about 3.25 GIG of RAM and that is hardware Dependant.

Some M'Boards work better than others and some will allow a 32 Bit OS to recognize & use more RAM than others when you are looking at the 32 Bit OS's upper Limit.

Basically Speed Tests are as useful as -**** on a Bull they may sound nice but in reality mean -Bugger All.

Way too often people look at Test Results and constantly push things as fast as possible and then wonder why Real World performance is not any better or only slightly different when they have spent thousands of $ to make things faster. Way too much depends on the OS and how well it is optimized for that Hardware and how the other Software that you use is Optimized for the Hardware.

After all it's pointless using a 2 X 8 Core CPU's if all of the software will only use 1 core. You are not going to get any real performance boost.

Col

Have you compared the same OS 32 vs 64 on the same hardware? It seems like you're changing too many things to be able to determine the source of the slow down.

Also, agree with Col, benchmarks tell you little about how usable the PC will be.

What's your Windows Experience Index score? It will rate the hardware on a scale of 1 - 7.9. Drivers can impact performance significantly.

I think [Who am I] hit the nail on the head. WinXP will be faster than Win7 on the same hardware regardless of 32/64 bit addressing. Now if you are comparing 32/64 bit versions of Win7 the 64 bit would be a tad slower, but not to the extent you state and probably only on I/O numbers. [Oh Smeg] and Mark Twain are right. There are lies, damn lies then there are benchmarks/statistics...

To make the comparison fair, you have to take many factors into account.

If the Windows 7 system is running the desktop in Aero mode, turn that off and your performance will improve dramatically.

As 4GB of RAM is the absolute maximum for a 32 bit system, install the maximum amount of RAM that the motherboard will take for the 64 bit comparison. One of the advantages of 64 bit architecture is the ability to use more RAM.

On the flip side, any 32 bit OS will use less power than the 64 bit version. Only 1 core of your multi-core CPU is fully in use with a 32 bit OS. Where a minimum of 2 cores will be in use for a 64 bit OS.

Chas

If you are running the 32-bit version of PassMark in all cases, you will always get lower figures on the 64-bit systems. The comments above about comparing XP to Win7 also apply. If you want to see the performance difference between 32-bit and 64-bit operating systems, you need to keep the OS version constant, otherwise you are looking at all other differences as well. And for more accurate results, the tests should only be run on clean systems (only OS installed with latest SP/hotfixes and no optional software installed at all).

Unless you are going to hit the RAM limit (and very few normal desktop users do) then 64 bit is always going to be slower. Programs will be larger (and take longer to load), DLLs are larger etc. Once you need the memory - and databases in particular gain here as you can hold the whole lot in memory - then 64 bit wins hands down as you avoid thrashing the paging system.