AMD brings turbo boost to Radeon HD7970
Should you happen to be in the market for a $500/£420 graphics card, AMD has launched a new contender for your cash today. I say new, but it's more a makeover: the Radeon HD7970 Gigahertz Edition is physically identical to the current AMD flagship, the HD7970, with a couple of minor tweaks to earn it that big sounding suffix.
The first is, as the name suggests, an increase to the core clockspeed from 925MHz to 1000MHz. To go with that the 3GB of memory has been accelerated to a full six gigahertz equivalent speed, putting it on a par with NVIDIA's top end GTX 680. More interesting, however, is the fact that AMD has also caught up with NVIDIA by introducing a feature for accelerating the HD7970 depending on the processing load and chip temperature, something which the latest GeForce cards were well praised for.
Is it enough to win back the title of fastest graphics card in the world? Does anyone care about such things any more?
The truth is that I don't really know, because we haven't had one of the Radeon HD7970 GE cards in to review yet. Price wise it's officially the same cost as the GeForce GTX680 it's to compete with, although it does look like it may be slightly better value when it goes on sale. There are already overclocked HD7970s available for £399 in the UK, while the cheapest GTX 680s are about £450.
The really interesting part of the HD7970 GE release is that automated overclocking set-up, which works in a similar manner to NVIDIA's GPU Boost and the turbo modes we're familiar with from both AMD and Intel CPUs. AMD is calling it PowerTune with Boost, as it uses a tweaked version of the existing PowerTune tool (you'll find it in the Catalyst drivers) to increase clockspeeds by up to 50Hz on demand. The frustrating thing is that nothing in the technical detail supplied by AMD suggests that the boost is reliant on any changes to the hardware – it looks like there's no reason it couldn't be backwards compatible with older cards, but probably won't be for marketing reasons.
A quick scan of early reviews across the web (Anandtech, TechRadar, Tom's Hardware et al) shows very consistent results. The new HD7970 GE looks to be very competitive against the GeForce GTX680: if not definitively faster, it wins some benchmarks and loses others. It does use considerably more power, however, and has a louder fan to keep it cool at those extreme speeds.
Personally, I'm not sure I'm that concerned by these downsides since I won't be queuing up to buy one any way. Neither the GTX 680 nor the HD7970 GE are fast enough to make them worth more than NVIDIA's excellent GTX670, which at around $399/£320 is considerably cheaper than either and just as capable in practical terms, and never more than a few frames per second slower in the benchmarks that count.
I'll let you know if my opinion changes after testing one in our labs.