AMD Radeon HD 7850 review
AMD's HD 7800-series graphics processors, codenamed "Pitcairn", sit in the middle of AMD's "Southern Islands" range of 28nm graphics chips, with the "Cape Verde" Radeon HD 7750 and Radeon HD 7770 below and the "Tahiti" Radeon HD 7950 and Radeon HD 7970 above. We were impressed by the strong performance of the £260 Radeon HD 7870, so were interested to see if the Radeon HD 7850 could measure up in the sub-£200 category.
The HD 7850 is only slightly cut down compared to the HD 7870. Both cards have 2GB of GDDR5 RAM and a 256-bit memory interface, and the HD 7850's core runs 140MHz slower, at 860MHz. The cheaper card also has 1,024 instead of 1,280 stream processors.
On the rear of the card are dual-link DVI, HDMI and twin DisplayPort outputs, which has become a fairly standard configuration for AMD cards. The HD 7850 needs only a single six-pin PCI Express power connector, so you should be able to upgrade PCs with even moderately-powerful PSUs.
The card's reduced clock speed and stream processor count compared to the HD 7870 made a big difference in our benchmarks. In our 1,920 x 1,080 Ultra quality Dirt 3 benchmark, the HD 7850 managed a super-smooth 56.7fps, but this was far off the 74.3fps of the HD 7870. When we stretched the game across three monitors in Eyefinity mode at 5,760 x 1,080, the frame rate dropped to 23.1fps – 7fps slower than the HD 7870's score and below the 30fps rate where we consider a game to be properly playable. The HD 7850 wasn't far off the HD 7870 in our Crysis 2 benchmark, with 24.9fps compared to 28.8fps, and once we turned off some of the fancier effects such as tessellation we saw a smooth 42.1fps.
The HD 7850 proved to be an excellent overclocker. Even with the core pushed up to 1,050MHz – a 190MHz overclock – we could run all our benchmarks without a problem. The benefits were modest, though, with just a couple of frames per second extra in our game tests.
The HD 7850 fits in well in AMD's new graphics card range. It's not a performance bargain like the HD 7870, but it provides plenty of gaming power at a reasonable price. If you already have a powerful last-generation card like the AMD Radeon HD 6950 there's no need to upgrade, but if you're building from scratch the HD 7850 is a good choice for a mid-range PC.
|Interface||PCI Express x16|
|Slots taken up||2|
|Graphics Processor||AMD Radeon HD 7850|
|GPU clock speed||860MHz|
|Architecture||1,024 stream processors|
|Power leads required||1x 6-pin PCI Express|