Does Crossfire/SLI double dedicated memory

[Slickrick214]

I had a question and this is something I've been thinking about. Lets say you have a Radeon 6970 video card that has 2 GB's of dedicated memory. If you were to double the 6970's in Crossfire does that double your dedicated video memory to 4 gigs or is it still only 2 gigs?

 

[farrengottu]

yes it doubles. each card only accesses its own memory. so it has to be double.

 

[rds1220]

I was under the impression that it doesn't double the memory. In the FAQ section it says

Do SLI or CrossFire double the memory
No.Adding another card with more memory doesn't double the overall memory of your cards

 

[de5_Roy]

no. cfx and sli do not double video memory. the 6970 has 2 gb for it's own gpu. in cfx and sli, the multiple gpu take turn to render one part of scene and they employ their own vram for that (amd and nvidia implement it differently afaik). so effectively, a cfx/sli combo works like a multi gpu card with the same amount of vram. that's why the vram does not increase (or double). some cards like radeon hd 6990 advertise 4 gb vram but that's the total video memory of the card. in reality each gpu has 2 gb of vram working in cfx. same for gtx 590.
http://www.tomshardware.com/forum/245454-33-crossfire-faqs

 

[Mousemonkey]

yes it doubles. each card only accesses its own memory. so it has to be double.

No it doesn't. The data is mirrored by both cards so two 1GB cards will still result in 1GB of VRAM being available.

 

[Slickrick214]

Best answer selected by Slickrick214.