AMD’s Radeon HD 5850: The Other Shoe Drops

“For those of you looking for the above and a repeat of the RV770/GT200 launch where prices will go into a free fall, you’re going to come away disappointed. That task will fall upon the 5850, and we’re looking forward to reviewing it as soon as we can.”

-From our Radeon HD 5870 Review

Today the other shoe drops, with AMD launching the 5870’s companion card: the slightly pared down 5850. It’s the same Cypress core that we saw on the 5870 with the same features: DX11, Eyefinity, angle-independent anisotropic filtering, HDMI bitstreaming, and supersample anti-aliasing. The only difference between the two is performance and power – the 5850 is a bit slower, and a bit less power hungry. If by any chance you’ve missed our Radeon HD 5870 review, please check it out; it goes in to full detail on what AMD is bringing to the table with Cypress and the HD 5800 series.

AMD updated the specs on the 5850 at the last moment when it comes to power. Idle power usage hasn’t changed, but the final parts are now specified for 151W load power, versus the 160W originally given to us, and 188W on the 5870. So for the power-conscious out there, the 5850 offers a load power reduction in lockstep with its performance reduction.

As compared to the 5870, AMD has disabled two of the SIMDs and reduced the core clock from 850MHz to 725Mhz. This is roughly a 15% drop in clock speed and a 10% reduction in SIMD capacity, for a combined theoretical performance difference of 23%. Meanwhile the memory clock has been dropped from 1.2GHz to 1GHz, for a 17% overall reduction. Notably the ROP count has not been reduced, so the 5850 doesn’t lose as much rasterizing power as it does everything else, once again being 15% due to the drop in clock speed.

With the reduction in power usage, AMD was able to squeeze Cypress in to a slightly smaller package for the 5850. The 5850 lobs off an inch in length compared to the 5870, which will make it easier to fit in to cramped cases. However the power connectors have also been moved to the rear of the card, so in practice the space savings won’t be as great. Otherwise the 5850 is a slightly smaller 5870, using the same sheathed cooler design as the 5870, sans the backplate.

Port-side, the card is also unchanged from the 5870. 2 DVI ports, 1 HDMI port, and 1 DisplayPort adorn the card, giving the card the ability to drive 2 TMDS displays (HDMI/DVI), and a DisplayPort. As a reminder, the DisplayPort can be used to drive a 3^rd TMDS display, but only with an active (powered) adapter, which right now still run at over $100.