Bamba wrote:
I don't think this argument makes much sense. Even if there's a shortfall in potential performance because a given card isn't getting further optimisations you'll still get a decent performance boost by adding a second one (compared to having the single one), even if it's not as much as it could be in an ideal world. Unless you're arguing that adding a second card will somehow result in less power than having a single one, which I assume you're not as that would be bonkers? Also, I don't think I've updated the drivers for my ATI card in ages and it's still happily trucking along. While driver updates might make a big difference when targetted at certain high profile game (e.g. Witcher 3, GTAV, etc) I'm not convinced they make a wild difference in general.
Well as JC has already noted, Crossfire is by far the weaker of the two implementations, so on an AMD card (ATI don't exist anymore!) you'll be stuck with Crossfire and AMD's shonky driviers and even shonkier Crossfire. (Also note that AMD's drivers suffer badly in DX11 when paired with a weaker CPU, so an AMD card that on paper should better an Nvidia card, actually delivers less performance in reality - loads of stuff about this at Eurogamer.)
Another thing to remember is that you're limited by the VRAM on a single card, so if you Crossfire two 1GB cards you still only have 1GB of VRAM as far as games are concerned.
So in my case for example, yes I could have tried SLI-ing another 670 with my existing 670, and that may well have given me enough grunt to run GTA5 at 2560x1440, but it would have done nothing to help with the fact that my chosen settings needed 2.5GB of VRAM and the 670s are 2GB cards, and as far as GTA5 (or any other game) would be concerned - 2GB of VRAM is still what I'd have, it doesn't pool it between the two cards.
Finally, it's important to note that you can get an awful lot of GPU grunt for a reasonable amount of money. The GTX960 for example will basically top out any game you chuck at it at 1080p/60FPS, and it costs £150 - and being as it's a new card it has the latest cool-running architecture, modest power requirements, low noise, up-to-date driver support etc. (I continue to be very impressed with the 960 in Mrs Hearthly's PC.)
Dropping down to a £100 card you can still get some excellent performance, which isn't going to be a whole lot more than you'd have to drop on a second card to try Crossfiring with whatever you have now. (Unless it's a real cheap thing in which case Crossfiring it probably won't help much.)
I'm not saying it's a total non-starter and yes it may be a decent budget option to eke some extra life out of an elderly single-card PC in certain circumstances, but personally speaking I think it makes more sense to move onto a new single GPU solution.