Sapphire Radeon HD 6770 FleX review

The ATI Radeon HD 5770 was one of our favourite cards from last year, with plenty of DirectX 11 gaming power at a reasonable price. For this reason we were keen to get our hands on the HD 6770 (now AMD rather than ATI-branded) to see if it could work the same mid-range magic. We've reviewed the more expensive FleX version of the card, from Sapphire, which has more versatile video outputs than the standard card (see below). You can buy a standard, non-FleX Sapphire HD 6770 here for just £76.

A quick look at the specifications shows that the HD 6770 is identical to the HD 5770 in almost every way. It has the same 800 stream processing units, 850MHz core clock speed and 1GB of 1200MHz GDDR5 memory. AMD is candid about this; its website says the HD 6770 is "based on the same hardware as the ATI Radeon HD 5700 Series". There is one key difference; the newer card has HDMI 1.4a support and the latest version of AMD's Universal Video Decoder (UVD) chip. The combination of these two factors means the card is now capable of Blu-ray 3D playback.

The FleX edition has a larger number of ports on the rear than most HD 6770 boards - you get a dual-link DVI port to connect to monitors with resolutions higher than 1,920x1,080, a single-link DVI port and HDMI and DisplayPort connectors. There are HDMI-to-DVI and DVI-to-VGA converters in the box, so you can connect three DVI monitors, DVI, VGA and HDMI, or HDMI, DVI and DisplayPort and so on - the card allows a flexible monitor configuration, hence the name.

It's also useful for AMD's Eyefinity triple-monitor gaming system. Stock AMD cards require that one of your monitors have a DisplayPort input, but such monitors are rare. Sapphire's FleX cards let you use the two DVI and the HDMI port in Eyefinity mode, so you can play games on two DVI and one HDMI monitor, or three DVI monitors using the included HDMI adaptor. With three 1080p monitors plugged in we could play Dirt 3 at 5,760 x 1,080 with High detail but no anti-aliasing at an average of 31.4fps, rising to 34fps at Medium detail.

If you don’t need the advantages that FleX offers, you're better off with the £76 non-FleX card. This price makes it around £35 less than the AMD Radeon HD 6850 which, while an older card, has currently dropped in price enough to make it a potential mid-range rival for the HD 6770.

In our Dirt 3 test, which runs the racing game at 1,920x1,080 at its absolute highest settings of Ultra detail and 4x anti-aliasing, the HD 6770 managed a smooth 35.6fps, which compares favourably with the HD 6850's 42.7fps. In our Crysis 2 benchmark the card could only manage 15fps, and the HD 6850, while faster, was still jerky with 19.7fps. Once we turned detail levels down to 'High', where the game still looks pretty but doesn't have the fancy DirectX 11 tessellation effects which add realistic bumps and craters, we saw a smooth 39.2fps from the HD 6770. Considering its low price, the card certainly punches above its weight.

The Radeon HD 6770 may not be anything earth-shatteringly new, but by releasing an already-competent card at a lower price AMD has produced our new favourite mid-range card. The standard, non-FleX card is very good value for its performance, and the FleX version makes it easy to game on three monitors at reasonable resolutions.