32 bit vs 64 bit: How it relates to video cards

[qubit]

under a 32 bit OS, each application can only use 2GB maximum.

Thats address space - and your video cards ram uses that. DX9 applications also duplicate into system memory - so with a 640MB card (only one counts, memory doesnt add in SLI) you have 640MB as a maximum address spaced used, as well as a duplication of that memory.

WORST case, with every video setting cranked to the max using all 640MB of video ram - you'd have about 800MB left over for your game. I'd expect it to be more around the 1-1.2GB mark.

You know, I'm curious to know what would happen if you used a graphics card with 4GB RAM on it on a 32-bit OS - that would theoretically grab the whole address space, so would the OS even boot properly?

 

[Fishymachine]

wow! Very informative post.



Does that mean, depending on the game, more video card memory will hurt you more than help? Using the same hypothetical, what if you have a 2gb card (like the new 285gtx), does that actually make performance worse then? I was thinking of buying a 285gtx 2gb to replace my two 8800gts.

Does this also mean that regardless of how much system ram you have on a 64 bit OS, 32-bit apps will only be limited to 2gb of vitrual memory thingy and therefore all that extra amount of ram you have is useless for that 1 particular 32-bit app? So the only plus side to running 32-bit apps (and 95% of games are still 32-bit unfortunately) on a 64-bit OS is the you can run 5 32-bit games at one time with minimal drag?

Also, I think the 8800 Geforces are Dx9 cards. So even if you are running Vista or 7, are you still confine to the memory mirroring problem?


So much memory chatter, this is confusing to me sometimes!

I aplogize if these are noob questions.

You can't play 5 games in 32 bit unless there from the "pre-gig" era,and every card (nvidia and ati) newer than the 8800gtx(including your GTS) are at least DirectX 10.0 what you should do is get a 64bit(preferably Win7) and since you want an upgrade now I recommend a HD 5850 or patience until the GTX 360/350

 

[Mussels]

You know, I'm curious to know what would happen if you used a graphics card with 4GB RAM on it on a 32-bit OS - that would theoretically grab the whole address space, so would the OS even boot properly?

no, the OS would reserve a minimum amount - most likely 2GB

You can't play 5 games in 32 bit unless there from the "pre-gig" era,and every card (nvidia and ati) newer than the 8800gtx(including your GTS) are at least DirectX 10.0 what you should do is get a 64bit(preferably Win7) and since you want an upgrade now I recommend a HD 5850 or patience until the GTX 360/350

his question was more that "if i have 8GB of ram, can i run 4 2GB programs at once" - and the answer is yes.

while many programs are still only capable of addressing 2GB each, x64 lets you run more of them at once - better multitasking.

 

[Mussels]

i've noticed threads get auto locked (and cant be unlocked) if they become a certain age with no posts. this post is just to prevent that happening here.

 

[qubit]

no, the OS would reserve a minimum amount - most likely 2GB

i've noticed threads get auto locked (and cant be unlocked) if they become a certain age with no posts. this post is just to prevent that happening here.

Hey, I'm glad you did - I'd missed your answer and forgotten all about my question.

 

[boise49ers]

Well I upgraded to 64 bit and ALL my games run so much better at their absolute highest setting and resolution. This has been by far the best upgrade I have done. My old copy and movie software won't work on 64 bit, but I'll just get a burner for my other system and do all that on that one.
Thanks Mussels !

 

[andreeebdg]

correct me if i am wrong... but i saw something mistakenly typing here here

in 32 bit system...

4GB system ram
2x1GB video cards (SLI/crossfire)
2GB system ram usable, 2GB left in games once video card ram is duplicated.
(SLI and crossfire only use one video cards ram. Because of how it works both cards ram is in the address space, but only one cards ram is duplicated)

in 64 bit system...

4GB system ram
2x1GB video cards (SLI/crossfire)
4GB system ram usable, 3GB left in games once video card ram is duplicated.
(SLI and crossfire only use one video cards ram. Because of how it works both cards ram is in the address space, but only one cards ram is duplicated)

now, does it looks that there's no duplication in 32 bit? or it should be

4GB system ram
2x1GB video cards (SLI/crossfire)
3GB system ram usable, 2GB left in games once video card ram is duplicated.
(SLI and crossfire only use one video cards ram. Because of how it works both cards ram is in the address space, but only one cards ram is duplicated)

Again, sorry if this has been discussed previously or i'm the one who misread.. and for my poor english too ..

 

[Mussels]

oh there is likely MANY typos! let me read your post in detail


I've since learned that only one card is in the address space, i'll go update the first post with the information found throughout the thread.

What typo are you pointing out, exactly?



edit: first post has been updated somewhat.

 

[andreeebdg]

oh no.. the 1st post has changed bit

here

32 bit system
4GB system ram
2x1GB video cards (SLI/crossfire)
2GB system ram usable, 2GB left in games once video card ram is duplicated.
(SLI and crossfire only use one video cards ram. Because ram isnt additive in SLI/Xfire, only one cards ram is duplicated)
32 bit system

or should it be?

32 bit system
4GB system ram
2x1GB video cards (SLI/crossfire)
3GB system ram usable, 2GB left in games once video card ram is duplicated.
(SLI and crossfire only use one video cards ram. Because ram isnt additive in SLI/Xfire, only one cards ram is duplicated)

I kinda confused between system ram usable and left at this point.

If usable 2GB then 1GB left for game as 1GB used for duplication or usable 3GB then 2GB left as 1GB used for duplication, ???

I see only the second state that is similar to every other combination.....

Again, i am sorry if i'm wrong.. and my poor english ...

 

[Mussels]

what it means is that while 3GB is usable, only 2GB per application. meaning that 1 of those 3GB could be leftover for the OS or whatever.

 

[shdssamir]

please help

i have a BFG gtx 285 2GB and 2 GB RAM, how much ram will be used on 32 bit OS ??
and how much RAM will be used if i have 4 GB RAM on a 64bit OS ???

thnx

 

[GSG-9]

please help

i have a BFG gtx 285 2GB and 2 GB RAM, how much ram will be used on 32 bit OS ??
and how much RAM will be used if i have 4 GB RAM on a 64bit OS ???

thnx

Please start a new thread and refinance this one as the source of your concern, it keeps everything cleaner.

and Welcome to TechPowerUp!

 

[shdssamir]

thnx

 

[Mussels]

please help

i have a BFG gtx 285 2GB and 2 GB RAM, how much ram will be used on 32 bit OS ??
and how much RAM will be used if i have 4 GB RAM on a 64bit OS ???

thnx

You really need a 64 bit OS for that much ram - otherwise you can only really use 512MB or so of video ram.

 

[shdssamir]

thnx for your reply

 

[El_Mayo]

Mussels!
what if.. you have 2gb RAM and a 1GB video card in 32bit windows 7?
it doesn't replicate the video RAM does it?

 

[Mussels]

Mussels!
what if.. you have 2gb RAM and a 1GB video card in 32bit windows 7?
it doesn't replicate the video RAM does it?

if you are running a DX9 game, yes it does.


The key there is how much Vram the games use - older games - no problems. games like MW2 at 1080P = problem (950MB according to some tests with GPU-Z on an nvidia card with max AA)

 

[El_Mayo]

if you are running a DX9 game, yes it does.


The key there is how much Vram the games use - older games - no problems. games like MW2 at 1080P = problem (950MB according to some tests with GPU-Z on an nvidia card with max AA)

dayumm.. okay.. so if it uses up to 1gb video RAM, that means the game can run only using like 1GB RAM?

 

[Mussels]

dayumm.. okay.. so if it uses up to 1gb video RAM, that means the game can run only using like 1GB RAM?

since MW2 uses upto 950MB of video ram, that means 950MB of duplicated ram as well - which is why the game crashes so often on 32 bit users and theres reports of the game being "buggy".

without max AA, but still at high resolutions you could imagine it using 700MB or so - 1400MB of 2048MB being used up, makes sense that the game would crash every half hour or so, as it used more and more ram every few levels.


32 bit OS's do not cut it for modern games, in DX9. its as simple as that.

 

[El_Mayo]

since MW2 uses upto 950MB of video ram, that means 950MB of duplicated ram as well - which is why the game crashes so often on 32 bit users and theres reports of the game being "buggy".

without max AA, but still at high resolutions you could imagine it using 700MB or so - 1400MB of 2048MB being used up, makes sense that the game would crash every half hour or so, as it used more and more ram every few levels.


32 bit OS's do not cut it for modern games, in DX9. its as simple as that.

so if i had 2gb RAM and a 64 bit OS, that'd fix it?
or be just as bad?

 

[Mussels]

so if i had 2gb RAM and a 64 bit OS, that'd fix it?
or be just as bad?

same thing.

2GB in 32 or 64 = pretty much same thing. while you wouldnt run out of address space, you'd still run out of physical ram (and either move to the page file (laggy gameplay, or crash)

But if you had 4GB of ram, then you'd have 4GB available in the 64 bit OS

 

[El_Mayo]

same thing.

2GB in 32 or 64 = pretty much same thing. while you wouldnt run out of address space, you'd still run out of physical ram (and either move to the page file (laggy gameplay, or crash)

But if you had 4GB of ram, then you'd have 4GB available in the 64 bit OS

oh okay that's alright then, i've got a 2GB kit, and i'll switch one of 'em out eventually to get 3GB.
I'll just stick with a 512mb card till i get 3GB

 

[Mussels]

oh okay that's alright then, i've got a 2GB kit, and i'll switch one of 'em out eventually to get 3GB.
I'll just stick with a 512mb card till i get 3GB

this is the part i feel like i dont get across well: just because its a 1GB card, doesnt mean the game uses 1GB of ram.


If you experience weird lag, or crashes: lower AA, texture details, or resolution and the amount of ram used will drop (as will the system ram duplicate)

 

[El_Mayo]

this is the part i feel like i dont get across well: just because its a 1GB card, doesnt mean the game uses 1GB of ram.


If you experience weird lag, or crashes: lower AA, texture details, or resolution and the amount of ram used will drop (as will the system ram duplicate)

that's because it's confusing!

 

[Mussels]

cod MW2 uses 950MB at 1920x1080 with 16xaa (thats what the user said/GPU-Z reported)

if you were to run it at 1280x1024 with no AA, it'd probably use <512MB (and thus, less than 512MB to be duplicated into system ram) - leaving you 1GB+ free for the game to run crash free