Introduction
The Radeon HD 4870 1GB sure dropped to $150 pretty quickly, didn’t it? The Radeon HD 4890 really isn’t all that far behind at $190 (as low as $170 with mail-in rebates). So, for the Radeon HD 5850 to be a success at $310, it’d better be appreciably quicker, right?$259
Nvidia has its own high-end bruisers around the same price range, too. A GeForce GTX 275 at $210 is mighty tasty. And a GTX 285—the company’s fastest single-GPU board available—isn’t bad at $330 or so given its single-GPU flagship status (less than $300, after some of those rebates).
If you haven’t yet checked out our review of the Radeon HD 5870, you might want to give it a quick peek. After all, the Radeon HD 5850 under our microscope today centers on the same fundamental architecture as that board (and I don’t think I can swing another 10,000 word story this week, so this piece isn't going to cover all of the GPU nuances).
Answering The Lynnfield Question
But that doesn’t mean we can’t break some new ground. One of the criticisms I saw come up in the comments section was that we used a $1,000 processor overclocked to 4 GHz for testing AMD’s Radeon HD 5870. Of course, that configuration was by design. These new GPUs are so powerful that we wanted to give them as much room to “breathe” as possible, without seeing congestion in the benchmarks due to processor bottlenecks. This presents a bit of a theoretical question to the folks running Core i7, LGA 1156-based Core i7s, a Core 2-series chip on P45, or 790GX. Mainly, does the move from a x16 PCI Express 2.0 slot to a x8 connection affect the performance of such a powerful GPU.
In order to help answer that, we took our Core i7-870 and overclocked it to 4 GHz on Asus P7P55D Premium. I suspect that in a Lynnfield-based configuration, the Radeon HD 5870 will be a less-popular choice than the cheaper Radeon HD 5850, so we tested a pair of 5850s on both Intel-based platforms to shed a little light on this one.
We also dropped the Core i7-870 to its stock speeds in order to isolate the effect of processor performance versus our overclocked Lynnfield-based results.
Is CrossFire Worth It?
When ATI launched the Radeon HD 4770 at $110, we couldn’t pass up the opportunity to compare two of the cards together against Radeon HD 4890s and GeForce GTX 275s. But the Radeon HD 5850 is not a cheap piece of hardware at $310. Due to availability issues, as of November 30th, a pair now costs $620. The only single card in that neighborhood is a GeForce GTX 295, which can be found for roughly $500 and hasn’t yet been discounted, despite AMD’s Cypress launch. To be fair, there isn’t yet a need, as the 5870s are still in extremely limited supply, so the challenge seems to be getting your hands on one.$259
But maybe the Radeon HD 5850 will change that. Today, we’ll be looking for a single Radeon HD 5850 to stand up to Nvidia’s GeForce GTX 285—a card AMD couldn’t contend with using a single-GPU solution in the past—and a pair of 5850s to at least eke past significantly best the GeForce GTX 295.