sli memory

OK I know this has been asked before but Google keeps sending me to different places but no real answer.
OK I havent used SLI but once when I had a 7950gx2 in my desktop.
I am about to get another 9800m gt to run sli in my clevo d900c. I would have gone for the gtx 280 but I think I would much rather have 192 cores over 128 and I think at this time 1gb of Vram isnt that big of a deal.
SO the question is, how does vram work in SLI? I know when the 7950gx2 came out Nvidia boasted that it had 1gb Vram. I want to know what happens to the second cards vram.

Thanks,
By the way the card is order and there is no need to say what I should have done or what this and that, just how does SLi vram work! thanks peeps

 

Welcome to the NBR forums.

First, I think you are a bit confused.
Nvidia 9800M GT = 96 shaders
Nvidia 9800M GTX = 112 shaders
Nvidia GTX 280M = 128 shaders

so the GTX 280M will outperform the 9800M GT by about 20-25%.

Secondly, when you SLI videocards, the memory will add together.

But videomemory is not important.... its the GPU that will drive the amount fo memory when needed.

anything more than 512MG GDDR3 on a 256-bit memory interface card (like a 9800M or GTX 200M) is a waste... and becomes a gimmick for people to purchase it.

many people get tricked into thinking a videocard is better if it has more memory.

Example: some people have thought that a 1024MB 9800M GTS is better than a 512MB 9800M GT.... wrong.

 

ok well i am not confused, see adding another 9800m gt will give me 192 cores vs the 96 that i currently use, and I thought when using sli the same memory is loaded on each card so, if the game uses 256 mb that will posted on both cards so they can work together.
Overall, I know that 2 9800m gt will outperform 1 gtx 280m. I just dont want to replace the card I already have just make it alittle better by adding another one.

 

Yes, the same texture information gets loaded onto both cards. They don't combined to make a single framebuffer.

Get the 2nd GT, much better performance for your money.

 

you are right.

I thought you were talking about single videocard comparisons.

so yes, a 9800M GT LI setup will definitely beat a single GTX 280M.

 

thanks guys, i should be recieving it within the next 2 weeks.
To be honest, there hasnt been a game besides Crysis (like always) that one 9800m gt cant handle.

 

NWN2 lags on my M860TU Shoddy coding, I suppose...

 

Wrong. The memory is not combined, both cards utilize the same amount of memory, limited to the single card's capacity.

For notebooks, more than 512MB vram generally is a waste, but lately 1GB cards have shown increases from their 512MB counterparts at resolutions as low as 1680 x 1050. But this doesn't apply for all games, and generally notebooks won't be pushing higher than 1920 x 1200.

 

mr fong you might want to check out Nvidia's website they have now notebook drivers that seem to help with allot of games. NWN2 I never played but all the games I have play perfect with no issues.

 

Rather have the GTX 280M, better power usage and you don't have to worry about SLi issues, but then again, you can always turn SLi off and use a single card in such a system.