Quote:
Originally Posted by Droogie;14168327
You can't sli a 1gb 460 with a 768. They're too different. Different amount of memory, different memory bandwith, and the 768 has fewer ROPs. Not compatible.
Should have read above, but must say it again. Also, don't go for the SE. You'd be better off picking up a used 460 of the marketplace here. They go real cheap.
Agreed. Although I'm about 98% sure the physical problem is with the memory bus width exclusively.
You can find examples (esp. with ATI/AMD) of cards successfully (sometimes needing to be hacked to work) doing multi-gpu with specs that are mismatched in pretty much every other regard: Stream Processor counts, ROP counts, memory amounts, heck even with DDR3/DDR5 mixed ... but TTBOMK there's never been an example of two cards doing multi-GPU with different memory bus widths.
I don't know for sure that it's an architectural limitation (in fact, I can't reckon why it
would be, esp. using Alternate Frame Rendering), but it seems like it probably
is, otherwise we'd have seen at least one example of it somewhere.
Edit: Come to think of it, I also can't recall a case where cards w/different CUDA (aka Shader) core counts could do SLI, but as it's possible with the AMD analog (SP count), I have to think that's not a physical limitation ... but I'm not positive on that.
Now, if it IS the case that one can successfully SLI 460's with 768MB + 1GB (192-bit bus width + 256-bit), then ... scratch what I said above
But (again, ttbomk) I don't believe anyone's done multi-GPU with cards with mismatched memory bus widths ... hack or no hack. Except with Lucid Hydra chipset, of course.