Broken down

When the 4870 X2 performs, it works extremely well. Given that the single 4870 is not all that far behind NVIDIA's GeForce GTX 280, it comes as no surprise to find the 4870 X2 has its measure when multi-GPU scaling is in full flow.

The 4870's performance in GRID also shows the benefits of all that video memory. The pair of 4870s in CrossFire mode really fall off a cliff at 2,560 x 1,600. No such problem for the 4870 X2 and its twin 1GB memory buffers. If memory availability is not an issue, the X2 scales largely identically to the 4870s in CrossFire.

That's the good news. Now brace yourself for the bad. The X2 fails to deliver in the one game where you really want maximum performance, Crysis – as do the 4870s in CrossFire mode. Both setups simply crash approximately five seconds after level loading.

Now, we suspect the X2 works as intended in 95 per cent of system configurations. But not, unfortunately, ours. Given more time and correspondence with AMD, we are sure that a solution will present itself. But without direct contact with senior AMD reps, that's not an option.

Hit-and-miss graphics card

We really want to like the new X2. In many ways, especially the memory buffers and multi-monitor support, the HD 4870 is a dual-GPU done right. And when it does work properly, it gets immensely fast results.

But the harsh truth is that as long as multi-GPU technology relies on driver profiles, it will be a flaky, hit-and-miss affair. And one that we can't in all conscience recommend that you buy.