windows 7 x64 worse performance than x86

[Aralkis]

specs:
phenom II x4 3.4Ghz 965 BE (same problem when I used an athlon x3 2.9Ghz
amd mobo ecs chipset 790gx
4gb ram kingstone
seagate 500gb 7200 rpm
ati r9 270x (same problem when I used a radeon hd 5750)
windows 7

For years games that run smoothly in windows x86, struggle to run on x64, be it a x86 or the x64 version of the game.

Since the problem persisted for years with all kinds of games and with diferent hardware and even after formating (I've just done a fresh reinstall) I have no Idea of what is going on. I usually am able to solve my own problems but this one has eluded me.

Some notes:
It is memory independent (I checked and monitered to see when the problem is lack of memory)
Happens in the majority of (heavy) games, even with the lowest graphic settings.
The problem is low fps, fps instability, staggering, etc..
when I ran the game in windows x86, it runs fine, even with high graphic settings.
I fell its something related to the processor, but it didn't improved even when I upgraded my cpu from an athlon II x3 to a phenon II x4 965
This happens in many games, from FPSs to strategy games like Total War and Civ5
I keep my drivers up to date.


The question is (again):
Why windows x86 perform so much better than x64? to the point when I only play games in windows x64 when the game is exclusive to this arch?

 

[Wile E Coyote]

I believe the main question when choosing between 32 and 64 bits is not "Does my processor support 64 bits — if so then I should use 64 because that's twice as good", but "How much memory do I have?".

64-bit programs use about 50% more memory then their 32-bit counterparts. The results of this are:

less code/data can fit into processor caches -> more cache misses -> your super-fast processor waits more for memory controller to fetch data from RAM. Processor also needs to read more data because it's more bloated.

Linux uses non-allocated RAM to cache disks. Less free memory available -> less space for disk caches -> slower disk access

Once you're out of RAM and the system starts swapping - disk access is thousands times slower than RAM, so any potential benefits of 64-bit code (see below) are flying out of window.

On the other hand, in 64-bit mode processor has more registers, so it doesn't need to access memory that often, also, some calculations (64-bit numbers etc.) are more efficient. So generally, code which is not memory-restricted runs slightly faster in 64-bit mode.

So, if your system has, say, 2GiB of RAM or less then I would definitely choose 32 bits. More than 4GiB - the benefits of 64 bits are becoming more prominent. Around 4GiB is a "grey zone" - you need to make a choice yourself.

I for one have been using both types of windows for a long time now and have not seen the issue you are suggesting.

This could be more like a hard ware issue not software.

Sounds to me like some thing could be failing and needs to be replaced.Since you all ready re placed the CPU than that is not the problem.

I am thinking RAM,Power supply,Hard drive,or video card,or mother board.

Start test with the simple stuff like RAM,Hard drive.Normally 90% of the time it can be one of them two start by pulling out the ram sticks when system is off.And restart system with one ram stick to see if the issue is still the same.This is how to test the ram if it's bad.

 

[Aralkis]

thanks for the reply. PSU, CPU, VGA are all relatively new (less than 2 years). My memory (i forgot to say that they are 2x2Gb ddr3 1333hz kingstone in dual-channel) , mobo and Hdd are all kind of old (mid 2010). I do admit that more memory wouldn't hurt. I'm thinking about doing a test with wine. I would bet that even a x64 linux running wine runs better than windows x64 (when wine works at all). I'm gonna test it.

I was just hoping too see if someone had a similar issue and had a magic configuration trick or some hint on how I could improve my situation. No luck I guess...