PDA

View Full Version : Regular question about dual gpu on single board



SAdam
09-24-2012, 06:17 AM
Hi All!

I am just asking about using for example an ATI 7990 for OpenCl computing.
Can the 6GB memory which is on the 7990's board be addressed with one buffer or OpenCL sees two devices in my rig with 3GB?


thanks in advance,
Adam

sean.settle
09-25-2012, 04:21 AM
Given that the 5970 and 6990 were dual GPU graphics cards seen by OpenCL as two GPU devices each with one half the total advertised memory, I would say that will also be the case for the 7990. You may receive more helpful replies to this question if you post it in the AMD OpenCL forum.

fireplace
09-26-2012, 10:39 AM
I second that, ask the manufacturer but expect it to see two independent GPU devices each at 3GB -> as if you'd plug two ordinary 7970s into your system.

Presuming you haven't purchased the card yet, if a large memory is an important issue, Sapphire has 6GB version of the 7970 Ghz Edition. The Ghz editions in general also have higher clock speeds for both GPU and memory, plus two physically individual GPUs can also use two x16 lanes concurrently. Add to that greater flexibility in alternative cooling solutions available and drivers natively provided (I suppose the just semi-official 7990 just uses ordinary 7970s drivers, but again ask), unless you really intend to stick multiple 7990s into your system (and have a cooling chamber available), I don't see any reason (neither technical nor pricing) for choosing a single 7990 over two 7970s. Though of course happy to hear good and sound opposing reasons!

cheers!