2x 8800GTX Sli, 4gb 800mhz ram, Vista 32-bit

[ViperMichael]

I have been doing alot of reading and i can't get a straight answer, some peole say 3gb other 3.8gb. If vista 32-bit can only address 4gb max, does that mean the Video memory is included so 1.5 gb GPU memory is taken away from system memory to leave me with only 2.5gb?

Would I be best to get the retail version of vista and stay with 32-bit for a while then upgrade to 64-bit, or just get a 64-bit oem straight away? Is it hard to install oem, and do you get all the normal support, is it geniune?

How are 64-bit drivers these days in general?

Any body with a similar setup it would be most interestin to hear you story?

 

[Golgatha]

Because of compatibility reasons, I would personally stay with the 32bit version currently. Get yourself a retail copy so you can order the 64bit version and upgrade later down the road.

On the memory question. 32bit apps can only address 2GB of memory per application and the OS can only address 4GB overall. The memory address space available in your BIOS will limit what the OS actually "sees" as available RAM. I personally put another 2GB in recently because of the depressed memory prices and my BIOS apparently can "see" 3200MB on bootup and the OS shows I have 3.12GB of physical RAM.

 

[nullpointerus]

Originally posted by: ViperMichael
I have been doing alot of reading and i can't get a straight answer, some peole say 3gb other 3.8gb. If vista 32-bit can only address 4gb max, does that mean the Video memory is included so 1.5 gb GPU memory is taken away from system memory to leave me with only 2.5gb?

Probably less. Windows adds 50% to your GPU RAM total, at least on many machines. My 512 MB video card meant that I ended up with 4096 - 512 * 1.5 = 3328 MB. So your dual 768 MB cards will likely put your usable system RAM at below 2 GB if I'm understanding this correctly--although SLI might mean that the 2x GPU RAM shares the same address space, in which case it would be more like 2944 MB.

Would I be best to get the retail version of vista and stay with 32-bit for a while then upgrade to 64-bit, or just get a 64-bit oem straight away? Is it hard to install oem, and do you get all the normal support, is it geniune?

I wouldn't bother with the 32-bit version. You can't upgrade from 32-bit to 64-bit unless you do a clean install (including wiping the hard drive), so that's a hassle. Many 32-bit Vista packages only come with the 32-bit disc even though they may advertise both; in this case, the 64-bit disc must be ordered separately for a small fee.

How are 64-bit drivers these days in general?

Good, unless you count sound/peripheral drivers, in which case you should list which exact models you have.

 

[nullpointerus]

Originally posted by: Golgatha
The memory address space available in your BIOS will limit what the OS actually "sees" as available RAM. I personally put another 2GB in recently because of the depressed memory prices and my BIOS apparently can "see" 3200MB on bootup and the OS shows I have 3.12GB of physical RAM.

That's right. Your hardware devices w/ memory get "memory mapped" into the highest regions (i.e. starting at 4 GB and working backwards). This used to be fine, but with huge amounts of VRAM and many peripherals, it *really* eats into the address space available for system memory.

To get around this limitation, even in a 64-bit OS, one must go into the BIOS and enable the memory remapping setting so that devices will get mapped way above 4 GB. The 32-bit Vista could technically have supported this using 36-bit PAE, but Microsoft decided not to support PAE in Vista for whatever reason.

So: Vista 64 + BIOS remapping = 4 GB RAM

 

[aka1nas]

Originally posted by: nullpointerus

To get around this limitation, even in a 64-bit OS, one must go into the BIOS and enable the memory remapping setting so that devices will get mapped way above 4 GB. The 32-bit Vista could technically have supported this using 36-bit PAE, but Microsoft decided not to support PAE in Vista for whatever reason.

So: Vista 64 + BIOS remapping = 4 GB RAM

They did that for the same reason as in XP: too many vendors write poor device drivers that map themselves into the 3.5-4GB area and cause conflicts if that RAM was free for the OS to use.

 

[krotchy]

Seriously, there is no reason to get 32 bit vista. I have yet to encounter something in Vista 64 that wasn't supported in 64 bit vista, but was in 32 bit vista. XPx64 was a totally different beast, with lots of compatibility issues, but I find in vista compatibility tends to spread across 32 and 64 bits identically.

 

[Acanthus]

64bit vista and 8800SLI still do not play well from what i hear.

I havent run into a game that runs over the 2GB mark in vista yet.

 

[TC777]

Originally posted by: nullpointerus

Originally posted by: Golgatha
The memory address space available in your BIOS will limit what the OS actually "sees" as available RAM. I personally put another 2GB in recently because of the depressed memory prices and my BIOS apparently can "see" 3200MB on bootup and the OS shows I have 3.12GB of physical RAM.

That's right. Your hardware devices w/ memory get "memory mapped" into the highest regions (i.e. starting at 4 GB and working backwards). This used to be fine, but with huge amounts of VRAM and many peripherals, it *really* eats into the address space available for system memory.

To get around this limitation, even in a 64-bit OS, one must go into the BIOS and enable the memory remapping setting so that devices will get mapped way above 4 GB. The 32-bit Vista could technically have supported this using 36-bit PAE, but Microsoft decided not to support PAE in Vista for whatever reason.

So: Vista 64 + BIOS remapping = 4 GB RAM

I assume that the Bios Remapping option wouldn't affect Vista 32bit? Or did you mean 32bit?