ATI introduced the Radeon HD 4890 GPU - ostensibly a faster-clocked Radeon HD 4870 - at the beginning of this month. Released in XT and OC variants, the new GPU competes against NVIDIA's also-new GeForce GTX 275 for superiority in the £190-£250 space.

Looking back at recent history, ATI doubled-up on Radeon HD 4870 with the X2 part - twin-GPU model - less than three months after the initial launch. Pulling almost 300W under load, it was, at that time, the fastest consumer graphics card around. Since then, however, NVIDIA has applied its own dual-GPU mojo in the form of the GeForce GTX 295, launched earlier this year, and faster in-game performance means that it holds the current title of fastest single gaming card.

Having the quickest card around does little for volume sales but an awful lot for perception: the halo effect, if you will. NVIDIA's been hammering the 'fastest top-to-bottom line-up' message to anyone who cares to listen, so it is reasonable to assume that ATI will try and reclaim that particular honour in the near future.

Thinking back to Radeon HD 4890, the obvious move would be to lash a couple together - a la Radeon HD 4870 X2 - and let partners release the Radeon HD 4890 X2 2,048MB at speeds as high as 1GHz core and 4,500MHz memory. Would that be fast enough to beat out the GeForce GTX 295 over a wide variety of benchmarks? It would be close, that's for sure.

Trouble is, Radeon HD 4890 OC currently draws around 190W when under load. ATI could probably reduce per-GPU usage a touch, again like HD 4870 X2, but we don't see the current possibility of a sub-300W card. Really, ATI's partners would be looking at 350W, and that's an awful lot of power to go through a single PCIe x16 slot. It's possible, sure, with two eight-pin power-connectors and an upgraded cooler, but the current economic climate is such that, unless ATI can guarantee a performance win, it's not worth the effort.

One method may well be to transition to a 40nm process for high-end parts and such a move would - or, perhaps, should - keep power-draw in check. 40nm is coming real soon with ATI's mid-range parts, so the supposition isn't as outlandish as it may at first seem.

We reckon that a highly-clocked Radeon HD 4890 X2 verges on the far side of pragmatic. Perhaps Sapphire will take up the challenge and design one, but we don't expect too many other partners to make the move. Rather, they'll rely on customers choosing two £200 Radeon HD 4890s and CrossFiring them instead, or waiting until DX11 parts come through. NVIDIA should keep the ultimate-speed crown throughout this summer, unless ATI can pull a rabbit out of the RV790 hat.

Would you buy a Radeon HD 4890 X2 for, say, £399? Let us know your thoughts.