XP64 generally slower than XP32

[Rakeesh]

Somebody did some benchmarks on this, and it doesn't look all that great.

http://www.extremetech.com/article2/0,1697,1857522,00.asp

I don't get it. Microsoft goes and breaks the kernel compatibility with 32-bit drivers, and then they don't even optimize the code for 64-bit? (then again, I suppose there isn't much to optimize for that in the kernel space)

[jolle]

Its old news that 32bit apps dont get any faster in WinXP x64.
3dMark05 gets a little better CPU score, Farcry gains about 2 FPS (And that is in 1280x1024, running 64bit is about CPU performance), the 64bit enhanced version is prolly just a straight off recompile to 64bit, which I think doesnt really do more them perhaps enable the game to adress over 4gb of RAM. (we've seen the same with Riddick before)
And the 64bit version features some extra graphical goodies doesnt it?

all that said, I still maintain that the "min fps" in CS:S was alot higher for me on WinXP x64, specially when the bomb goes off and all that physics is running, didnt dip as low as it used to on WinXP32, CS:S is ofcource 32bit, Havok on the other hand is supposedly available in 64bit aswell, it would be odd if the version in HL2 could run both modes tho, but it would in that case perhaps explain it..

[Rakeesh]

Well, the thing that gets me is that by and large it is actually significantly slower, whereas you'd expect maybe one or two fps faster.

It could have something to do with the 64-bit kernel being based on win2003, and that itself underwent many server specific optimizations.

[jolle]

only thing I could se being slower is the 32bit rendering apps, I would chalk that up to a minor loss in WOW64 per clock..
games, PCmark, 3dmark and all that is either same or slightly better/worse most of the time.. how is that "by large significantly slower"?
And why would it be faster? its emulating 32bit with WOW...

the conclusion being:
We're really encouraged by the minimal performance losses and encouraged by the potential gains of 64-bit applications.
Pros: Full support for 64-bit processors; 64-bit application support (if you can find them); good performance with 32-bit apps.

[Wolfhound]

only thing I could se being slower is the 32bit rendering apps, I would chalk that up to a minor loss in WOW64 per clock..
games, PCmark, 3dmark and all that is either same or slightly better/worse most of the time.. how is that "by large significantly slower"?
And why would it be faster? its emulating 32bit with WOW...

the conclusion being:


Yes it´s emulating but keep in mind that is a hardware emulator AMD64 has native support for 32 bit not as Itanium in this case WOW64 is like Wine for linux

Fortunately, you don't have to walk away from 32-bit code in order to embrace 64-bit software. The AMD64 architecture, found in the Opteron and Athlon 64 processors from Advanced Micro Devices, extends the popular x86 instruction set to support 64-bit memory addressing, enabling compatible operating systems to run both 64-bit and 32-bit applications at full speed on the hardware. That's native-instruction-set execution, folks—not mere
emulation of 32-bit software by using 64-instructions.

Such compatibility isn't something that you can or should take for granted with all 64-bit processor architectures. For example, Intel's Itanium 2 processor is also a 64-bit chip, but because its architecture is not at all similar to that of x86-based systems, it can only run 32-bit apps by emulating the x86 instruction set. This results in a significant performance degradation for 32-bit apps running on that processor. The AMD64 architecture imposes no such performance hit, because it can execute x86 instructions, and applications, natively.

In fact, in many cases 32-bit apps run faster on the 64-bit AMD64 architecture than they would on an equivalent 32-bit x86 processor. This is due to the fact that AMD64 processors eliminate the front-side bus architecture that dominates in x86-based systems today. By integrating the memory controller, and using industry-standard HyperTransport technology for chip-to-chip communication, AMD64 processors reduce the bottlenecks and latencies commonly found in other x86-based systems.

in my expirence games perform almost the same, some 2-5 fps up some 2-5 fps down, so I don´t see the "by large significantly slower", in fact the system is more responsive in normal desktop work

[j0j081]

If you ran 64 bit XP you would know the speed boost in Windows itself makes it worth the change. If my 32 bit apps are any slower it is by no means noticeable. Multitasking is way smoother. As someone said, for the most part MIN FPS is up in games which is what counts. Far Cry with the extra content is amazing. 64 bit Firefox beta is amazing, and from what I've heard the newest version of Photoshop runs much faster. I don't really get the point of this thread.

[Peoples-Agent]

Aye, I'm back with XP32 right now solely because I am awaiting on some more drivers and software that I tend to use alot to be made for the 64 bit platform first off.
I have to say, I find it to be alot more responsive and seems to make better use of RAM even with just 1GB.

[seeker010]

no different than the change from 16->32 bits. best to wait for 64bit apps before passing judgement.