Sapphire Toxic HD 4890 Review

There's an arms race brewing among ATI's board partners. Now that ATI has a GPU that can easily scale to frequencies like there's no tomorrow, ATI's board partners are currently locked in a clock speed war for all the bragging rights.

The GPU in question is ATI's recently released Radeon 4890. While it’s fundamentally based on the same architecture as the Radeon 4870 with 800 stream processors and 256-bit memory interface with GDDR5 memory, ATI has made a number of tweaks under the hood of the 4890’s RV790 GPU in order to enable higher clock speeds. Decoupling capacitors have been added in order to reduce signal noise at high clock speeds, while the GPU has been tweaked to consume slightly less power than its predecessor. Higher voltages also help the chip scale to higher frequencies, with ATI revamping the board’s power subsystem so it delivers more juice to the GPU. ATI also says they’ve retimed the entire chip to run at higher frequencies.

And enable high frequencies is exactly what they’ve done. The Radeon 4890 is clocked 100MHz higher than its predecessor – 850MHz. If you recall previous reviews of Radeon 4870 cards we’ve looked at over the last year, you’ll know that the 4870 generally topped out around 780-800MHz, and could really only go over that amount with specialty cards that offered the option of manual voltage adjustment. In comparison, the Radeon 4890 starts where only a select group of 4870 cards could be OC’ed to with a little bit of luck; and with a little bit of OC’ing, the 4890 scales much further from there – 1GHz is within reach with a quick slide of the mouse in Overdrive and some luck.

Or if you want something a little more certain, ATI’s board partners are brewing a crop of factory OC’ed 4890 cards that are fully backed by warranty. This has led to the clock speed war that we talked about.


Sapphire is one of the principal combatants in this war. Considering their history of providing some of the fastest tricked-out Radeon cards on the market though, that probably shouldn’t come as much of a surprise to most of you. Their Toxic line of video cards are known for their mixture of high clock speeds with superior cooling.


Sapphire’s got a new Toxic Edition card for the Radeon 4890 GPU, and as expected, Sapphire once again ups the ante by mixing factory OC’ed speeds with their exemplary vapor chamber cooling+heatpipes. Sounds intoxicating doesn’t it? The really sweet news is that’s not all Sapphire’s done with their latest Toxic board. Sapphire’s upped the card’s power subsystem as well. Let’s take a closer look shall we?