We had a brief look at Sapphire's Radeon HD 4850 X2 in November when this board launched, but at the time there was no official driver support from AMD since the company simply provided us with a pre-release hotfix driver that wasn't available for download. This driver had just some issues where performance dived through the floor on games and then we learned that official AMD support wasn't forthcoming until at least Catalyst 9.1. With Sapphire eager to get ahead of the game though, it has recently released a version of the Catalyst 8.12 driver with a modified file that enables support for the Radeon HD 4850 X2 card. The driver is certified and available for download, but isn't quite official from AMD. - Bit-Tech

Sapphire Radeon HD 4850 X2 2GB Cool Twins Review

At the time of our initial preview of the card, a number of ATI board partners had come to us to say that they were planning to release their own Radeon HD 4850 X2's very soon. And so far, none of those promises have rung true and Sapphire has maintained its exclusivity in the market. At the same time, the card's price has dropped a bit since November, it's now available for under $350. The card has the same number of stream processors as the Radeon HD 4870 X2, which means there are two full RV770 cores under the heatsink each with 160 five way shader units, totalling an impressive 1600 shader processing power.

The clock speeds are exactly the same as a single Radeon HD 4850 as well with their core is clocked at 625MHz, while the GDDR3 memory runs at 1986MHz effective. Unlike the standard Radeon HD 4850, Sapphire has included 1GB of memory per GPU on this Radeon HD 4850 X2 card instead of the 512MB on a standard Radeon HD 4850. There is another, cheaper version of the card with 1GB of GDDR3 that retails for about $325 though, so we'd definitely recommend spending that little bit more on the 2GB variant based on the comparisons we've done between single 512MB and 1GB based Radeon HD 4800 series so far.

Considering how low the operating temperatures are on Sapphire's Radeon HD 4850 X2, we expected the graphics card to overclock fairly well and we weren't disappointed. We managed to increase the core speed from its default 625MHz up to 696MHz while the memory was just quite happy running up at 2300MHz effective. We are very much in two minds about Sapphire's Radeon HD 4850 X2 2GB, because although the card is generally a better performer than NVIDIA's recently released GeForce GTX 285, there are a number of issues that we can't ignore. The main one being AMD's support for it hasn't been that forthcoming.

Despite these flaws, the Sapphire Radeon HD 4850 X2 does deliver a generally better gaming experience than NVIDIA's more expensive GeForce GTX 285. The cheapest we have been able to find the GeForce GTX 285 for is around $399, which makes it $50 more expensive than the Radeon HD 4850 X2. That makes the decision difficult and while we'd typically recommend a single GPU solution almost every time, the price difference makes it an awkward choice. Frankly, the Sapphire Radeon HD 4850 X2 is too loud for a modern gaming system, driver support isn't where we'd like it and the GeForce GTX 285 is too expensive.

In light of this, we don't believe there is a perfect choice in this segment of the market and it opens up a window of opportunity for the manufacturer who wants it the most. Right now, we'd avoid this part of the market altogether and either go higher or lower depending on your screen size and budget elasticity.