32-bit Memory Limit

[ajkochev]

Possibly a dumb question. I have a 32-bit computer running Windows 7 Pro with 4 gigs of system memory and a video card with 1 gig of onboard memory. Both are DDR2. A friend told me that the OS and system can only read 4gigs TOTAL in 32-bit and that I should remove some system memory to speed up games since my video memory is likely not being used?

Is this true?

[Niclo Iste]

The 32 OS part is technically true it should see about 3.5 gigs of RAM, however I don't understand his rationalization that taking the video card out would speed up games. The card itself has its own built in memory to speed its own performance and is not directly used for temporary file storage as RAM is in the OS.

[ajkochev]

Sorry for the confusion. I would remove some system memory, not the video card. The system would then see and use the memory in the video card. Since it would be under the 4gig limit again. According to his thoughts.

[CeeBee]

False. The video RAM is unrelated to the system RAM.
Also making a blank statement that a 32-bit OS can only see/use 4GB of RAM is wrong. Workstation OS's cannot make use of more than 4GB, but some server OS's can...

[Ferrit]

And to add to what CeeBee said.
Infact 4 gigs is only in Vista 32 bit and Windows 7 32 bit because of an windows update that addresses it
XP is completely limited to 3.2 gigs I beleive.

[Niclo Iste]

Well now I just feel silly. Thanks for correcting me, I haven't done enough win7/vista and assumed their 32bit counterparts were like xp and I don't work with servers at all.

[Ferrit]

Hey no sweat. Its all very very very confusing.
Information contradicts each other all over the place

[CeeBee]

Memory limits by OS: http://msdn.microsoft.com/en-us/library/aa366778%28VS.85%29.aspx
As you can see some editions are limited below the 4GB (2GB for Win7 starter, 1GB for Vista starter, 2GB for Win2003 server Web edition, 512M for XP starter...)

[Platypus]

So ajkochev, the upshot of this is that your friend is mistaken. There is no point removing system memory - Windows just winds back the amount of system memory it uses, to make room for however much video memory there is.

What's more, since recent motherboards will use memory in Dual Channel mode, removing a portion of the system RAM will usually reduce the performance, either because of reverting to single channel mode, or reducing the RAM to 3GB when Windows otherwise uses something higher like 3.2GB.

[Matridom]

Time to add some murkiness to the whole affair.

Windows 32 (xp, Vista and 7) bit can address a TOTAL - between ALL DEVICES - of 4 gigs of ram. memory allocation is addressed by system components first, then system ram.


So in this case, 32 bit windows, 4 gigs of system ram, 1 gig on the video.

Windows will address 1 gig to the video card, then 3 gig to the system RAM. Allowing you to effectively use 3 gigs of ram. If you have more ram then this amount, it sits in your computer un used.

Myth: Windows vista and 7 32 bit can use 4 gigs of ram regardless of what video card you put in. Windows will show 4 gigs of ram if that's what's installed. This was provided via a windows update to vista and inlcuded in 7 to appease the OEM retailers. People would buy systems with 4 gigs of ram, but windows would only show 2 gigs (dual video cards with 1 gig each). Tech support was then on the line to explain to these users why windows showed less ram, and why the company sold them a computer with more ram then could be used.


Ferrit, XP is not limited to 3.2 gigs, it's a lot closer to the 4 gigs , most video cards now have 512 megs of ram that makes the "standard" looke like 3.7/3.8 (256 meg video card) or 3.2 (512-768 meg video card).

[CeeBee]

Windows 32 (xp, Vista and 7) bit can address a TOTAL - between ALL DEVICES - of 4 gigs of ram.

Again, it's the flavor of the OS that decides how much can be addressed by allowing PAE to be used... See my previous screenshot of a 32-bit Win2003. However there is a limit of 2GB per process.

[Matridom]

Again, it's the flavor of the OS that decides how much can be addressed by allowing PAE to be used... See my previous screenshot of a 32-bit Win2003. However there is a limit of 2GB per process.

That screenshot is a unique situation for server OS's that use PAE to bypass the normal limitation. (by using virtual 32 bit memory space per application thread). The end result is that, yes, you can use more ram, but you are still limited to the 32 bit process and a total cap on what each process can use. If you want to go down that route, you can look at some server application (like MS SQL) that can exceed the 2 gig limit per process using similar extensions. There will always be exceptions, but in this situation, it's not the norm.

The original thread was based on desktop OS's and wether windows 7 32 bit could use a full 4 gigs of ram when a beffy video card was installed. My explanation adressed that. I did not use server os's as an example and i did not want complicate the explanation by drawing in all the possible exceptions.

I'm a firm believer in K.I.S.S.