Multiple instances on GTX295

I haven't found a definitive answer regarding the 295's
abilities running 2 instances. Some say that the technology
of the chips aren't cut out for it. But does crunching with
2 instances gain any improvement at all ? or is it not just
a performance gain like the newer cards ?
The GPU load on my 295's are around 75 to 80% load.

Does anyone have a clear answer to this ?


The Wizard

I have an older 9500GT 1gb that I'm running 2 instances on, it runs fine at 99% load and is faster at completing cuda's than ever before. Hope that helps.

This is what I have tested:

512mb 1 instance: (if you do two, there is nothing left for the system and makes it really laggy and choppy). 512mb8600GTS
1gb 2 instances: 1gb 9500GT
2gb 4 maybe 5 instances: Two 2gb GTX560 (have not tested 5 instances yet, but I run out of cuda's very fast on that).

I would definitely agree that the 295 should certainly be able to do two instances.

Anyone else have any thoughts about running
2 instances on GTX295 ??

Increased or decreased RAC ??


The Wizard

The general rule is about 500MB per instances. GTX 295 is a bit of an oddity with 1.8GB of memory. 448 bits, 896MB of memory per GPU, it may not handle 2 instances well but if you turn on SLi you should be able to run 3.

I'll let the 295 expert speak first, I skipped the 200 series when i went from 8800 to 470 a few years ago.

Another question not directed to GTX295 specifically.

I have a mobo with 2 x 16x pci slots and 1 pci 8x slot.

Is there any drawbacks to have 3 PCI 16x cards in that
mobo. is the 8x slot negative when running seti for that
16x card !?


The Wizard