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

[de.das.dude]

xp is ready to retire to the old OS home and join DOS and windows ME!

xp should really go home!!!

 

[GenTarkin]

yeah that was covered, it was something we learned later on. Games can reserve set amounts, or us dynamic amounts - and i too have seen many games using a 256MB limit. Its easy to go above it however, when you add in external things such as forcing AA/AF from the driver control panel.

oh ok cool =), well the reservation of memory by a game really has nothing to do with address space dedicated to the video card =)

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On another note, regarding PAE...yes it allows a CPU to address 36bit address and theoretically allowing a 32bit OS to use up to 64GB of ram I believe it is...
But the problem as someone said earlier is the design of MS drivers being the limiting factor on desktop OS's and why they wont be able to address higher then 32bit memory.

Their 32bit server os's on the other hand do take full advantage of PAE as their drivers are PAE aware and can see up to 64GB of RAM.

Linux also, easily can see a higher amount of memory with PAE aware kernel and compiled drivers for PAE...which is a much simpler approach.

Also, the only thing XP 32bit used PAE for was the Execute Disable bit technology as it functioned in the higher 36bit area. Thats why PAE is enabled on most XP box's where before the Execute Disable bit came out...you wouldnt see the "Physical Address Extension" in the system properties.

 

[Graogrim]

*cough* I don't mean to start an argument here or anything, but I feel obliged to point out that hardly any "real" games these days use the GDI (the part of Windows responsible for the duplicated memory assets). The GDI is for rendering fonts and lines and ellipses and such in desktop windows, and lacks any kind of animation support. It certainly does not support 3D.

If your application is using D2D, D3D, OpenGL, or is rendering video then it is *highly* unlikely (though technically possible I suppose if the programmers were insane enough to do it) that it is relying upon the GDI at all.

What this means in practice is that the effect of this duplication is not nearly so dramatic as to completely mirror the video card's entire set of onboard memory, but rather just the memory required by the specific windows that use the GDI. A good way to think of it is not that the video card's memory is being duplicated in system RAM, but that system RAM allocated for GDI use is being duplicated in the GPU's on-board memory for final rendering to the screen. Shared memory architectures benefit from Windows 7's GDI improvements the most because the GDI effectively has hitherto had to double-dip system RAM whenever a new window in which it is used is opened.

It's also noteworthy that apps which use GDI+ under Windows 7 are still reliant on software rendering, and therefore will not benefit from the WDDM 1.1 improvements.

Added: Of course that doesn't have direct bearing on the duplication of 3D resources (usually cached textures, meshes, shaders and the like), but there are similar implications for cached resources in 3D apps. It's not literally duplicating the video card's entire address space.

Sorry if this duplicates anything that's already been said...8 pages make it a bit tough to keep track of everything everyone has posted so far.

 

[Mussels]

*cough* I don't mean to start an argument here or anything, but I feel obliged to point out that hardly any "real" games these days use the GDI (the part of Windows responsible for the duplicated memory assets). The GDI is for rendering fonts and lines and ellipses and such in desktop windows, and lacks any kind of animation support. It certainly does not support 3D.

If your application is using D2D, D3D, OpenGL, or is rendering video then it is *highly* unlikely (though technically possible I suppose if the programmers were insane enough to do it) that it is relying upon the GDI at all.

What this means in practice is that the effect of this duplication is not nearly so dramatic as to completely mirror the video card's entire set of onboard memory, but rather just the memory required by the specific windows that use the GDI. A good way to think of it is not that the video card's memory is being duplicated in system RAM, but that system RAM allocated for GDI use is being duplicated in the GPU's on-board memory for final rendering to the screen. Shared memory architectures benefit from Windows 7's GDI improvements the most because the GDI effectively has hitherto had to double-dip system RAM whenever a new window in which it is used is opened.

It's also noteworthy that apps which use GDI+ under Windows 7 are still reliant on software rendering, and therefore will not benefit from the WDDM 1.1 improvements.

Added: Of course that doesn't have direct bearing on the duplication of 3D resources (usually cached textures, meshes, shaders and the like), but there are similar implications for cached resources in 3D apps. It's not literally duplicating the video card's entire address space.

Sorry if this duplicates anything that's already been said...8 pages make it a bit tough to keep track of everything everyone has posted so far.

microsoft themselves said that aero using WDDM 1.0 (DX9 hardware/PS2.0) duplicates in vista/7, and you need DX10 hardware to run WDDM 1.1 to prevent it in win 7. while i do not disagree with your information (since some if its over my head) - i trust that information from MS.

 

[Melvis]

Just wish there was a program we can run to see how much vram is been used in each game we fire up, this would help a lot in determining how much RAM we really need in our gaming rigs, or if we are hitting the limit?

At a guess id say 99% of games wouldn't even use 1GB of vram while playing? I have no idea.

 

[Mussels]

Just wish there was a program we can run to see how much vram is been used in each game we fire up, this would help a lot in determining how much RAM we really need in our gaming rigs, or if we are hitting the limit?

At a guess id say 99% of games wouldn't even use 1GB of vram while playing? I have no idea.

no way to tell Vram that i know of. it needs to be supported in the video cards and drivers for that to work.

I THINK some Nvidia cards + GPUZ can show Vram used, but not all of them, and not ATI.

 

[slyfox2151]

Just wish there was a program we can run to see how much vram is been used in each game we fire up, this would help a lot in determining how much RAM we really need in our gaming rigs, or if we are hitting the limit?

At a guess id say 99% of games wouldn't even use 1GB of vram while playing? I have no idea.

there is,

its called GPU-Z lol. goto the sensors tab and it will show how much video ram is being used.

(only if your video card supports it.)

 

[Melvis]

no way to tell Vram that i know of. it needs to be supported in the video cards and drivers for that to work.

I THINK some Nvidia cards + GPUZ can show Vram used, but not all of them, and not ATI.

Yea shame ATI dont have drivers/support for this yet, would help alot, least i can tell with my 8600GT's.

I never even thought about GPU-Z, and yea since owning a ATI card i haven't noticed it.

there is,

its called GPU-Z lol. goto the sensors tab and it will show how much video ram is being used.

(only if your video card supports it.)

Yea i know since using an ATI card for the past few yrs i haven't even seen it in GPU-Z, but now i know its there its time to do some testing with my SLi rig, see how much games realy use. And yes the 8600GT's are supported.

 

[GenTarkin]

Well here is what I have discovered regarding VRAM. I run all my games @ 1680 x 1050. Usually w/ 4x AA and 16AF.

Most modern games, and vantage / unigine use somewhere between 300MB-650MB VRAM depending on the game at this resolution and AF / AA settings. So, a card 1GB of VRAM is called for in gaming at this resolution sometimes =)

Its no longer the days of, oh you only need 512MB if your playing and lower - medium resolution with little AA.

This is on a nvidia GTS250

I am getting a GTX 460 this week as replacement, if the VRAM usage changes due to architecture I will let you know=)

 

[CDdude55]

no way to tell Vram that i know of. it needs to be supported in the video cards and drivers for that to work.

I THINK some Nvidia cards + GPUZ can show Vram used, but not all of them, and not ATI.

GPU-Z detects how much VRAM is being used on my GTX 470.

Didn't know it doesn't show up for ATI cards.

 

[Graogrim]

microsoft themselves said that aero using WDDM 1.0 (DX9 hardware/PS2.0) duplicates in vista/7, and you need DX10 hardware to run WDDM 1.1 to prevent it in win 7. while i do not disagree with your information (since some if its over my head) - i trust that information from MS.

Sure, and nothing I said was intended to flat out disagree, it's just that based on some of the posts I read it seemed like some folks had the wrong idea. For instance, the entirety of the video card's address space is not copied to system RAM. Also, depending on the API being used by any given app, even Windows 7 with DX11 is not completely immune to the replication of resources.

 

[Mussels]

Sure, and nothing I said was intended to flat out disagree, it's just that based on some of the posts I read it seemed like some folks had the wrong idea. For instance, the entirety of the video card's address space is not copied to system RAM. Also, depending on the API being used by any given app, even Windows 7 with DX11 is not completely immune to the replication of resources.

we thought the entirety was at first, however we learned later on that its not. It uses bits at a time, which CAN lead up to the entire amount of Vram - so most games lock it (256MB is rather common - they hit 1.75GB of ram used and CRASH)

 

[Graogrim]

That will only ever be the case if the game in question actually loads enough textures and other resources at once to entirely fill video memory. One way around that is to use algorithmically generated textures on the fly. That can cut memory requirements down to nothing more than the workspace required to generate any given single texture at once. Various demoscene apps--especially those that have to fit their executable and supporting files in a very small space--historically do this more often than actual games. It's slower than reloading from a cache in system RAM but usually faster than reloading from disk.

Strictly speaking, games don't HAVE to use that sort of caching, and some don't--those are the ones that don't use things like procedural textures and take a while to get going again after you've alt-tabbed out and back in again.

 

[somebody]

Also, the only thing XP 32bit used PAE for was the Execute Disable bit technology as it functioned in the higher 36bit area. Thats why PAE is enabled on most XP box's where before the Execute Disable bit came out...you wouldnt see the "Physical Address Extension" in the system properties.

The XD bit is not somewhere in the 36bit area but actually bit 63. PAE uses 64-bit page tables.

If you were lucky enough to have had 4GB of RAM with XP SP1 then it would have been up to the user to enable PAE since it wasn't enabled by default, and have full use of all 4GB of RAM. That is if the user was also lucky enough not to have bad drivers and BSOD's. Needless to say the user's luckiness of using all 4GB would shortly disappear in SP2.


Okay, back OT.

Not really sure what this is supposed to be showing, it doesn't tie in with what I see on my own system. With Vista running a hundred windows of 512x512x32 (1MB) results in 200MB of physical memory no longer available where as in 7 it's 100MB. Ties in with half the memory but can't see the connection with the above graph from Tom's.

 

[cadaveca]

RAMMap 1.1 was released a month ago...with this app it's possible to monitor device driver memory usage:

http://technet.microsoft.com/en-ca/sysinternals/ff700229.aspx

Ati also ahs a tool for monitoring vga ram usage, available on the amd dev site. GPU-Z can tell you nvidia ram usage, and with RAMMap, you'll know how much the driver uses as well.

 

[Mussels]

Okay, back OT.
http://media.bestofmicro.com/2/3/207435/original/image_thumb_8.png
Not really sure what this is supposed to be showing, it doesn't tie in with what I see on my own system. With Vista running a hundred windows of 512x512x32 (1MB) results in 200MB of physical memory no longer available where as in 7 it's 100MB. Ties in with half the memory but can't see the connection with the above graph from Tom's.

thats one of the graphs we found, yes.


the graph may be total BS, but the halfing of memory/reduction of memory/address space used is the key. with such a poorly documented 'feature' its been a bitch finding ANYTHING about it.

 

[Mussels]

RAMMap 1.1 was released a month ago...with this app it's possible to monitor device driver memory usage:

http://technet.microsoft.com/en-ca/sysinternals/ff700229.aspx

Ati also ahs a tool for monitoring vga ram usage, available on the amd dev site. GPU-Z can tell you nvidia ram usage, and with RAMMap, you'll know how much the driver uses as well.

please link to this ATI tool (or download it/reupload it if normal users cant get it)

 

[somebody]

RAMMap 1.1 was released a month ago...with this app it's possible to monitor device driver memory usage:

http://technet.microsoft.com/en-ca/sysinternals/ff700229.aspx

Thanks for the link. I like the fact that it shows AWE usage. Some initial problems running without a pagefile is that in Vista it appears to need an extra ~300MB of virtual space to refresh. ie If the program is already up and running and I run a memory hungry program that leaves less then ~300MB of RAM / virtual, then try to use the refresh button it crashes. Will have to look into it some more.

 

[alfieabel]

Many (if not most) of working memory cards sealed with a bitmap image memory built in video card, which is transferred to the physical screen memory in a copy operation managed by a function transfer printing equipment. The block transfer takes a chunk of memory at a time and transfers it to the screen buffer bit real. little size it says speed is produced. 32 bits at a time, 64 bits, 128 bits or more. The more bits, and transfer is carried out.

 

[remixedcat]

I got a sidebar gadget that tells me how much vram I'm using.

 

[genta3d]

How about a 32bit windows server ?
It can using 16GB of ram right ?

 

[Mussels]

How about a 32bit windows server ?
It can using 16GB of ram right ?

there are some tricks server OS's can do to see more ram, but keep in mind the limitations: its still locked to 2GB per application making it pointless.

 

[genta3d]

So is it really can make up to 16GB ?
BTW, I really need RAM to play multi client game. For the game is just 700-800mb RAM need it. But I want to open 20-30 client in one computer. And I need it in 32bit, since some program got bad in 64bit...

 

[Mussels]

So is it really can make up to 16GB ?
BTW, I really need RAM to play multi client game. For the game is just 700-800mb RAM need it. But I want to open 20-30 client in one computer. And I need it in 32bit, since some program got bad in 64bit...

i dont know if it can, google didnt help me much.

 

[Nokiacrazi]

EDIT : Lol, sorry for reviving the thread... in all honesty I read the last post as november...oh well.

Useful thread. First page was especially helpful.

I am currently thinking of buy a new computer. I will give the specs that I plan to use so I can then ask my question.


Gigabyte GA-870A-UD3 870 Socket AM3 8 Channel Audio ATX Motherboard
AMD Phenom II X4 965 Black Edition 3.4GHz Socket AM3 8MB L3 Cache 125W Retail Box Processor
OCZ 4GB (2x2GB) DDR3 1600MHZ Gold AMD Memory Kit CL8 1.65V
Sapphire HD 6870 1GB GDDR5 Dual DVI HDMI Dual Mini Display Port Out PCI-E Graphics Card

My questions are - Using this build mainly for gaming (dx10/11) will the RAM be a bottleneck for the graphics card?

Are any of the components bottlenecks for each other?

Would I have considerably/more performance in gaming with a AMD Phenom II X6 1055T 2.8GHz 9MB Cache Socket AM3 Retail Box Processor using the same build?

Would I have considerably/more performance in gaming with OCZ 4GB (2x2GB) DDR3 1600MHz AMD Black Edition Memory Kit AOD Ready CL8(8-8-8-24) 1.65V using either builds?

Would I have consderably/more performance in gaming with Gigabyte GA-890FXA-UD7 890FX Socket AM3 8 Channel Audio Out XL-ATX Motherboard in any of the combinations?

And finally (sorry too many questions for a newbie ) If I had the Sapphire HD 6870 1GB GDDR5 Dual DVI HDMI Dual Mini Display Port Out PCI-E Graphics Card in crossfire x2, would I need more RAM? What PSU would I need? Would it be compatible with any of the combinations?