Widescreen Gaming Forum

i will try the 64bit first before windows 7
i had vista and ran into lots of compatibility issues with games

i want to avoid that with windows 7

W7 works quite well with games actually. I'm running W7x64 atm. All games have worked for me so far. (even older ones).

Some games do give me a bit of trouble, but not sure if it's due to widescreen or the new processor (hyperthreading), or w7. But i've always been able to correct it after some googling (and help from this forum), and i'm no computer whiz or anything.

allright people i have another tech question for you

i read on another forum that i would need a true 64bit OS in order for the gtx 275 1792mb to run at full potential

is this true or not?
i have a 32bit xp now, but could upgrade if need be

headaches included, installing evrything from scratch :?

that's not true.

if you use a 32bit OS it can only address 3GB ram (talking about vista and XP here).

so the graphics card memory would take 1792 of the 3064 (or whatever it is)... leaving you like 1.3GB of ram. plus the page file.

that's wrong

[quote]if you use a 32bit OS it can only address 3GB ram (talking about vista and XP here).

so the graphics card memory would take 1792 of the 3064 (or whatever it is)... leaving you like 1.3GB of ram. plus the page file.

This is interesting. Partly because it's widely considered 100% accurate... and yet for some reason it isn't always.

I've got 4GB of RAM in an XP system. When I had a 512MB 8800GT installed, maximum available RAM was 3.25GB. I pulled the 8800GT and installed a 1GB Radeon 4850, maximum available RAM 3.25GB. Out of interest, I pulled that card too and stuffed in an old 2MB PCI Rage II card... maximum available RAM 3.25GB. PAE extensions are not enabled.

By the logic of subtracting RAM... I should not be seeing 3.25GB of RAM with the 1GB 4850 installed. It should be at most 3GB, and likely 2.25GB. And yet I am seeing 3.25GB - the same amount as with a 512MB card, or a 2MB card. The system is perfectly stable and happy...

so if i have 4 gig in my system
using xp 32 bit, games are played with only 3 gig?

best thing is to upgrade to 64bit os and the gtx will use all its and system memory?

On paper, a 32-bit OS can only address a maximum of 4GB of memory. That is system RAM and graphics RAM.


that's not completely the truth. however the point about microsoft is good, though graphics RAM has nothing to do with that.

ok now that I have said that the total story is a bit long so I'll make another post right after this one.

ok first

-what's the difference between a 64 bit OS and a 32 bit OS?
the main point is that a 64 bit OS with a 64 bit able processor can address more memory than a 32 bit OS

-how limited is a 32 bit OS on the memory side?
a 32 bit OS can address up to 4GB of addressable memory
but this addressable memory is absolutely not equal to physical memory.


In fact there is a bunch of reserved memory addresses for communicating with devices and the like, which means less memory addresses available for addressing physical memory. (which means less than your physical memory available for apps & games...)

so 1st, there's absolutely no correlation between the amount of video memory and available physical memory
however any device might reserve some...

2nd PAE allows to expand the addressable memory on 32bit OSes, though microsoft disabled that ability for WinXP even if PAE is activated for other purposes.

In practice, on winXP 32 bits you will never have more than 3.0 to 3.5 GB of available physical memory, whatever is your amount of physical memory. However, I will say it again, this does not influence video memory at all.

http://en.wikipedia.org/wiki/Physical_Address_Extension
http://msdn.microsoft.com/en-us/library/aa366796%28VS.85%29.aspx
http://support.microsoft.com/kb/888137


Bottom line, if you got more than 3GB of memory you should get a 64 bit OS for using it all.

also another limitation of 32 bit OSes is that applications are limited to 2GB each. Though there is a way to increase this to 3GB if the application supports it (that's called LAA http://www.amd.com/us-en/assets/content_type/DownloadableAssets/Expand_Memory_of_32-bit_App_-_Microsoft_4GT-_6204.pdf )

edit: even more info here :
Memory Support and Windows Operating Systems
Using /LARGEADDRESSAWARE on 64-bit Windows for 32-bit programs
The oft-misunderstood /3GB switch
Why can't I see all of the 4GB of RAM in my machine? (there's also a nice little drawing to show things.)

edit2: if you still don't believe me (which you shouldn't if you took time to read official msdn blog articles & rest of links) you might want to know that with my GTX285 2GB I get more than 3GB available memory on XP32

another good read : Gaming In 64-Bit: Tom's Tests, Microsoft Weighs In : Introduction

though if you begin to read it, you should really read it all from page 1 to conclusion, since some "critical" information is distributed through all pages, and some of the first pages could let you think some things which are cleared out after ...

yeah i made a typo i meant to put 4096.

but i dont quite think it is quite as cut and dry or consistent as you insist Whismer.

My gfs machine should have 4096-512-x. when she had her old 256MB card it was slightly higher than it is now, but not 256MB different

some guy here....

http://www.tomshardware.co.uk/forum/page-258883_15_0.html

2x 512MB graphics cards in SLI, 4GB ram and a 32bit XP OS and he gets 2GB RAM aparently. when he removes a card a lot of memory returns.

im not saying your wrong, what i was trying to say was it might be a problem depending on what game you are running. i have 0 problems, i run XP x64, sometimes when running 2 accounts on WoW with a lot of stuff open i get near 3GB used ram according to task man, depening what you are doing, with nearly 2GB graphics ram and the so called "4gb limit" on 32bit os (before you factor in PAE) might be "near the limit" as the man in the interview on the Tomshardware link said.

and as for no correlation... a 1792MB gpu will not only reseve 2MB to play nicely with the rest of the system

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@ whismerhill:

if you say "In practice, on winXP 32 bits you will never have more than 3.0 to 3.5 GB of available physical memory, whatever is your amount of physical memory. However, I will say it again, this does not influence video memory at all."

does that mean that with my win xp 32bit version, which has 4 gig ram, i would play games at 3 to 3.5 gig PLUS my 1792mb from the vidcard?

i'm thinking i shouldn't upgrade to 64bit os at all then

@ whismerhill:

if you say "In practice, on winXP 32 bits you will never have more than 3.0 to 3.5 GB of available physical memory, whatever is your amount of physical memory. However, I will say it again, this does not influence video memory at all."

does that mean that with my win xp 32bit version, which has 4 gig ram, i would play games at 3 to 3.5 gig PLUS my 1792mb from the vidcard?

i'm thinking i shouldn't upgrade to 64bit os at all then

There is no reason not to upgrade to a 64bit OS, namely Windows 7 RTM at this time.

all things considering
do you think i'm bottlenecking my system if i put a gtx275 1792mb card in to this system:

intel core 2 quad Q6600 2.4ghz
MSI P35 Neo-FI
Antec Sonata III Atx Case 500Watt Earthwatts
Western digital 320 gig SATA II
GEIL 2x2048 DDR2 800 Ultra dual channel

@ whismerhill:

if you say "In practice, on winXP 32 bits you will never have more than 3.0 to 3.5 GB of available physical memory, whatever is your amount of physical memory. However, I will say it again, this does not influence video memory at all."

does that mean that with my win xp 32bit version, which has 4 gig ram, i would play games at 3 to 3.5 gig PLUS my 1792mb from the vidcard?

i'm thinking i shouldn't upgrade to 64bit os at all then

no video memory & main memory are two completely different thing which don't add up.
- video memory is just for the graphic card and store what should be displayed on screen and other data which will be processed by the graphic card. (like textures for example)
-main memory is for everything else.

The 1792mb are just for the vidcard

The 3~3.5GB are used for: Windows, caches, any launched application (like antivirus or browser for example) and games.

Though any single application can't access more than 2GB of data unless it's programmed for it AND that the /3GB switch is enabled in windows (only for windows XP PRO or Media center editions)

if you really really don't want Windows se7en 64 bit then windows XP 64 bits is also an option.