Just need to clarify this. When a 6990 with 4gb of Vram is used for a game, (flight sim), does it use the 4gb ram all at once or is it split the same way as when using Xfire, ie: the system still only "sees" 2gb at any one time.
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HD6990, does system see 2 x 2gb or 1 x 4gb
- Thread starter pieman109
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I Think i read somewhere that the 6990 can actually effectively use 4GB (2GB per gpu) vram by sharing it in some new way (it is not mirrored) unlike two 6970s in xfire which will be able to use 2GB max or the gtx 590 with 1.5GB usable vram.
Either way my 6990 sees 2.5 to 2.6GB vram usage in BF3 at only 1080p and everything ultra except no msaa.
Either way my 6990 sees 2.5 to 2.6GB vram usage in BF3 at only 1080p and everything ultra except no msaa.
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It works differently with the 6990 because of the internal XFire bridge it uses, your system should recognise it as 4gb
2GB per GPU is exactly what I said.
If you have a link to show it's not mirrored please share it.
Which is 1.25-1.3GB per GPU.
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That's 2GB per GPU unless you have a link which shows different.
Well as you say 1.25-1.3GB still adds up to over 2GB so it can't be mirrored but I'll look it up later when I get on the PC.
Why can't it be mirrored?
1.25-1.3GB per GPU adds up to 2.5-2.6GB of mirrored data.
It's no different than me having a pair of 2GB cards using 1.25-1.3GB each.
A program like MSI Afterburner will show a total VRAM usage of 2.5-2.6GB but it's still 1.25-1.3GB per GPU/card.
The HD 6990 physically has 4GB of VRAM but effectively 2GB.