Performance does not scale on reference 7990 cards when overclocking, as your own link shows (sorry, I should have been more specific, I guess...). It's limited by underbuilt power circuitry. A pair of 7970s at that clock would be doing substantially better because they have more robust power circuitry.
Also, here's a reading comprehension question for you... have I been talking about REFERENCE 780s, or CUSTOM 780s? Hint: not reference. Also TPU's game suite is more robust than Guru3Ds, but I digress... obviously OP can look up specific benchmarks for his games and see if they are ones that behave well with the 7990 or not.
And it still doesn't matter IMO... the biggest problems with the 7990 are coil whine + no upgrade path. If a card pumps out 200fps but gives you a headache after 10 minutes of gaming, what good is it?You would really not mind having this in your rig
? Edited by BigMack70 - 10/16/13 at 2:44pm