Price-wise, the 5750 sits in direct competition with Nvidia's GTS 450, and here's where the real battle lies. Alone, the 450 offers extremely competent performance at middling resolutions – close on 60fps in Far Cry 2 and 30fps in the considerably more demanding Just Cause 2. As you'd expect for a budget card, it runs out of puff at higher resolutions, but not as quickly as the 5750.
Pair it with a twin, however, and the whole game changes. The performance of the 450 in SLI mode at 1,680 x 1,050 is nothing less than stellar: 70fps in DiRT 2, 125fps in Far Cry 2, 57fps in Just Cause 2 and 40fps in the massively demanding Heaven 2.0 Benchmark. It not only pushes the HD 5750 CF setup into the shade, it outperforms a single GTX 460 by a very tangible margin.
The setup is even capable of driving healthy performance at 1,920 x 1,200, with 98fps in Far Cry 2 and a still-playable 29fps in Just Cause 2. Like any lower memory-bandwidth budget card, it's always going to run out of juice before its bigger stablemates, especially as more demanding games appear.
But in terms of mid-range poke, we're frankly astounded. This means sad things for the HD 5770, which in CrossFire mode, can barely keep up with the GTS 450 pairing at 1,680 x 1,050. The 5770 handles Just Cause 2's engine more adroitly than the Nvidia equivalent, but only just.
What's more, a pair of 5770s will set you back around £50-£70 more than a pair of 450s, which clock in at around £198, and outperform a single 460 at 1,680 x 1,050. Do you feel a conclusion coming on?
Well, stop right there. There's more to ATI's 5770 – and indeed its whole HD lineup – than just gaming performance. It's incredibly quiet, power-efficient and it allows you to use ATI EyeFinity for multi-screen setups.
The only downside to the latter being that as far as gaming goes, you need a much fatter GPU to drive multiple panels at decent frame rates. For gaming on mid-range cards then, EyeFinity is a bit of a pipe-dream. But if you want a quiet, efficient, cool system that's capable of wholly competent frame rates at mid-range resolutions, then an HD 5770 CF setup is still a serious consideration.
And what of the GTX 460, the most expensive single card on test? The Zotac models we benchmarked clocked in at just a shade cheaper than a pair of GTS 450s, and while a single 460's frame rates at all resolutions couldn't quite compete, it's pairing them up that makes the difference for high-resolution gaming.
At £380, you get a properly high-end setup, with serious high-end results. So high, in fact, that a pair of 460s will comfortably outperform a single GTX 480, which will set you back the same price.
The price-performance ratio prize, however, has to go to the pair of GTS 450's in SLI mode. Great mid-range performance for under £200? We'll take two.