ATI refreshes it's fastest single-GPU board

The videocard industry typically works on an 18-month cycle for each GPU design. Last year, Nvidia released the GT200 and ATI launched the RV770. Both are speedy, DirectX 10-capable parts, packed with shader processing power and capable of running the most demanding games at top speed. We tested Nvidia’s first refresh of the GT200 last month (the GeForce GTX 285); now it’s time to put ATI’s first re-spin of RV770 under the microscope, with Asus’s Radeon EAH4890 TOP.

The 4890’s RV790 GPU is built on a 55nm process, just like its predecessors; however, ATI made fairly significant tweaks to the GPU’s structure in order to accommodate higher clock speeds. Asus’s stock overclock is a testament to that revamp. The Asus board’s stock clock is 900MHz (the default stock clock for 4890 boards is 850MHz). Likewise, the board’s quad-pumped GDDR5 memory sits on the same 256-bit bus but runs at 1,000MHz (the stock speed for 4890 boards is 950MHz). The star of the Radeon 4890’s show remains the GPU’s 800 shader units, which handle the heavy lifting in shader-heavy modern games, such as Crysis.

Under the custom Asus heatsink is a GPU primed for overclocking. Crank the voltage up and watch this baby purr.

Like the RV770-powered boards, the Radeon 4890 supports DirectX 10.1, a feature absent from comparable Nvidia parts. As is the case with Nvidia’s PhysX physics-acceleration tech, there’s a dearth of DirectX 10.1 games available today, and even fewer that you’d actually want to play. We really enjoyed Far Cry 2, but not enough to consider DirectX 10.1 a key differentiator. (For what it’s worth, we don’t consider PhysX support a key differentiator either).

While the 4890 is definitely faster than the Radeon 4870, it’s not stellar, especially in bandwidth-limited benchmarks, such as Call of Duty 4. In Crysis, which is typically limited by the performance of your card’s shader units, we saw the 4890 eke out a win against Nvidia’s highest-end single-GPU board, the GeForce GTX 285. However, the GTX 285 cleaned the 4890’s clock in every other test we ran, from 3DMark Vantage to Far Cry 2. The Far Cry 2 score is especially perplexing. We expected better performance from the 4890, since Far Cry 2 is one of the few DirectX 10.1 titles available today.

The Asus board offers a special tweak that helps differentiate it from typical reference designs. Using the included Smart Doctor software, you can tweak the GPU’s voltage—something that’s traditionally been difficult to do. The tool allows you to overvolt the GPU from 1.31V to 1.4V, which was enough for us to get the core to 1GHz, good for an 8 percent boost in most benchmarks.

The 4890 is a capable DirectX 10 card priced about $100 less than the GeForce GTX 285 we reviewed last month. However, the best value at this price range remains the Radeon 4850 X2 series of boards.

Asus Radeon EAH4890 TOP

The Hold Steady

Great performance for less than $300; low power requirements; great overclocker.

The Shins

Slower than the GTX 285.

Asus

Benchmarks

	Asus Radeon 4890	GeForce GTX 285	Radeon 4850 X2
Driver Version	8.592 RC1	182.08	8.12
Crysis 4X AA/Very High (fps)	21.4	20.3	12.4
Crysis No AA/Very High (fps)	24.9	24.8	27.9
Call of Duty (fps)	62.5	74.6	80.7
Vantage Game 1 (fps)	15.69	19.45	17.54
Vantage Game 2 (fps)	12.04	14.3	14.3
Far Cry HQ, 1920x1200, no physics, no AI (fps)	51.33	57.91	60.31
Far Cry HQ, 1680x1050, no physics, no AI (fps)	55.72	65.11	64.88

Best scores are bolded. Benchmarks are run on an Intel Core 2 Quad Q9770 Extreme, with 4GB of memory running Windows Vista. Crysis, and 3DMark Vantage are run at 1920x1200, with 4x AA and 8x anisotropic filtering, unless otherwise noted. Call of Duty is run at 2560x1600 with 4x AA.