AMD Radeon HD 7950 review

The Radeon HD 7950, codenamed Tahiti Pro, is the second card we’ve seen in AMD’s new Southern Islands range of graphics cards, and is a step down from the Radeon HD 7970, codenamed Tahiti XT.

The HD 7950 is 12mm shorter than the HD 7970 and has the same outputs on the rear panel: DVI, HDMI and twin DisplayPort sockets. Depending on the board manufacturer, the card should come with an HDMI-to-DVI adaptor and an active Mini DisplayPort-to-DVI adaptor, so even if you don’t have a DisplayPort monitor you can use three monitors in Eyefinity mode. You can also buy active DisplayPort adaptors for £18 from www.lambda-tek.com.

The HD 7950 has the same 3GB of GDDR5 RAM and 384-bit memory bus as the HD 7970, but the RAM is clocked at 1.25GHz instead of 1.38GHz. There are some significant changes to the core: the cheaper card’s GPU runs at 800MHz instead of 925MHz, and it has 1,792 instead of 2,048 stream processors. The lower power also means you only need a power supply with two 6-pin PCI Express plugs rather than one 6-pin and one 8-pin plug.

In our Dirt 3 test, which we run at 1,920 x 1,080, Ultra detail and with 4x anti-aliasing, the HD 7950 managed 73.9fps, compared to the HD 7970’s 88fps. When running Dirt 3 in Eyefinity mode at 5,760 x 1,080, again with Ultra detail and 4x anti-aliasing, we saw a smooth 34.2fps, compared to 41.5fps from the more expensive card. In Dirt 3, the HD 7950 has around 84 per cent of the performance of the HD 7970 for 75 per cent of the price.

Next page – Crysis 2, overclocking and verdict

However, the card was particularly impressive in Crysis 2, which we run at 1,920 x 1,080 with Ultra detail and using the high resolution texture pack. In this test the HD 7950 was slightly faster than the HD 7970, with 45.4fps compared to 42.9fps. We re-tested the HD 7970 with several different sets of drivers but were unable to make it match the HD 7950’s score. Crysis 2’s high-resolution textures take up a large amount of graphics memory, so both cards’ 3GB of RAM may be the bottleneck, and there may still be some teething problems with the HD 7970’s drivers.

Unfortunately, the HD 7950 doesn’t have the HD 7970’s overclocking prowess. While we could push the HD 7970 up to 1,125MHz core speed and 1,575MHz memory speed – increases of 200MHz and 195MHz respectively – we could only get the HD 7950 up to 900MHz core and 1,350MHz RAM, which are increases of just 100MHz for both the core and graphics memory. At these speeds Crysis 2 jumped up to 51.7fps, but this couldn’t match the HD 7970’s 57.5fps overclocked score.

The HD 7950 is a highly capable card which is good value compared to the HD 7970; it can play current games smoothly at their highest detail levels, even with three monitors in Eyefinity mode, so we don’t see much reason to spend the extra £100 on the HD 7970. There is some competition from the last-generation Radeon HD 6970, which is currently £250, but that card’s 2GB of RAM hampers it in the hugely-demanding Crysis 2 test. For the moment, the Radeon HD 7950 is the high-end graphics card to buy.