Force3D Radeon HD 4850

When it comes to 3-D gaming, ATI is finally beginning to retake ground from the all-conquering NVIDIA. With its recent dual-GPU boards getting the thumbs-up from gamers (Radeon HD3870 X2, EAH3870 X2 1GB etc.), and an aggressive pricing strategy that has left its competitor reeling, many punters are predicting a return to ATI market dominance. Whatever the outcome, it's definitely good news for consumers, with high-end graphics cards now shipping at mainstream prices. This brings us rather neatly to the ATI Radeon HD 4850: currently the most powerful mid-range graphics card on the market.

So what's new about the Radeon 4800 series of graphics cards? Despite being largely based on the previous R600 architecture, the new chip comes with a range of improvements that provide substantial performance-boosts in gaming. The most significant change is the number of stream processors, which has leapt to 800 (ATI's previous chip had a mere 320). The board's transistor count has also increased from 666 million to 965 million, while the number of texture units has more than doubled from 16 to 40. The mid-range HD 4850 version comes with a core GPU clock speed of 625 MHz, a memory data rate of 2.0 Gbps, 512 MB of GDDR3 memory at 993MHz (1986 MHz effective) and a 256-bit memory bus. It also benefits from an improved maths processing rate (one TeraFLOPs, rather than 0.497).

The other day, we reviewed AMD's reference board design, which this Force3D version is basically identical to. Force3D is a new name in the graphics card industry; in fact, until now we had never heard of them (its parent company, Inno3D, may be more familiar). At present, Altech Australia is tossing up whether or not to release the card over here, but with US prices expected to fall below $170, it should be quite affordable regardless.

If you're a tree-hugging greenie (which in today's world you should be), then the HD 4850's power consumption will bring a smile to your face. During peak usage, the card is rated at a mere 110 Watts; but boy, does it get hot! Despite the valiant efforts of the single slot copper fan sink, our card reached temperatures in excess of 80 degrees — and that was while idle. Overclockers may therefore need to think about additional cooling options before they attempt to max out the clock speeds.

For connectivity, the board comes with the usual range of HDTV outputs, plus two DVI connectors with dual-link support — a plus for high-def screen setups (a DVI-to-HDMI adaptor is also included in the sales package). The built-in audio system on the RV770 has also been upgraded to include 7.1 channel HD audio.

In our benchmarks, the Force3D HD 4850 comfortably trumped NVIDIA's 9800 GTX, which was previously the most powerful single-GPU graphics card on the market. Although the GTX returned a slightly better result in 3D Mark 2006 (12,074 versus 11,918) the Radeon came out on top in our gaming tests. When we ran the game F.E.A.R. with maxed-out settings, the HD 4850 averaged a respectable 93fps (frames per second). When using the same test-bed, the Gigabyte GeForce 9800 GTX (GV-NX98X512H-B) returned a result of 80fps — a difference of 13 frames per second. In our Half-Life 2 performance test, the Radeon card delivered an average 167.9fps. Again, this was slightly better than the GTX, which averaged 162fps. Lost Planet: Extreme Condition also impressed us with an average frame rate of 66fps (compared to 59.0fps with the GTX).

Things were slightly less rosy in our DirectX 10 gaming tests, but the results were still very impressive for a mid-range graphics card. Our first DX10 test was the infamously demanding Crysis, which we ran with maximum settings enabled at a resolution of 1920x1200. This returned an average frame rate of just 16.7fps. On the other hand, the DX10 version of Lost Planet: Extreme Conditions averaged a very playable 27fps, while Call of Juarez zipped along at 42.4fps. While none of these results will wow hardcore gamers, the cost-to-performance ratio remains incredibly solid. Indeed, for the same price as a high-end graphics card, you could combine two or even three of these babies in a CrossfireX arrangement for a massive boost in performance.

The Radeon HD 4850 also supports DirectX 10.1: a DX10 API update which, in theory, provides incremental enhancements to compatible games. At present, the real-world benefits of DirectX10.1 are barely measurable, but it's a good investment to have for the future.

(There is no Australian pricing available yet; the Force3D Radeon HD 4850 retails for $US199 in the US.)