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Burnt_Ram
04-06-06, 08:59 PM
hey all,

got a second 7800GT coming, and i'm wondering, that since the cards are 256mb each. does that meen i'll have 512mb effective ? it think i read somewhere it doesn't work like that tho !?! :(

Darkfalz
04-06-06, 10:29 PM
Nope, each GPU only has access to its own memory. If they were to share memory then it would go very slow as texture data etc. has to go over the SLI link which no matter how fast is going to be heaps slower than the native bus.

It's just like my Voodoo5, which has 64 MB ram but two GPUs, meaning effectively only 32 MB.

I'm not sure if they share framebuffer memory though, like my Voodoo5. If it was the case, then memory used for double/triple buffering and FSAA would be shared, and hence using less memory than a single card solution.

Burnt_Ram
04-07-06, 09:15 AM
Nope, each GPU only has access to its own memory. If they were to share memory then it would go very slow as texture data etc. has to go over the SLI link which no matter how fast is going to be heaps slower than the native bus.

It's just like my Voodoo5, which has 64 MB ram but two GPUs, meaning effectively only 32 MB.

I'm not sure if they share framebuffer memory though, like my Voodoo5. If it was the case, then memory used for double/triple buffering and FSAA would be shared, and hence using less memory than a single card solution. thanks for the explanation.