Sapphire’s version of ATI’s latest graphics card may appear to be just another release in the 4000-series, but it’s the first graphics card to have a 40nm Graphics Processing Unit (GPU).
This new manufacturing process results in smaller, cooler chips than those made with the 55nm process.
The HD 4770 costs a little less than ATI’s Radeon HD 4830. That card is our current top choice for gamers on a budget, so the HD 4770 has a lot to live up to. In many ways the new card is similar in design to the HD 4830. They have the same number of stream processors and the same amount of memory. The key difference is in the GPU speed, with the HD 4770’s running at an impressive 750MHz, compared with the HD 4830’s 575MHz.
Design differences make it very hard to compare the cards’ memory speeds directly. The HD 4770 uses a narrow 128-bit memory interface. This could cause a bottleneck, but it’s largely offset by the use of fast GDDR5 memory. In comparison the HD 4830 has a 256-bit memory interface but uses slower DDR3 memory. According to ATI, the HD 4830’s overall memory bandwidth is slightly higher.
It’s results that count, though, and here the HD 4770 takes a slim lead. It produced 52fps in our Call of Duty 4 benchmark at a resolution of 1,680×1,050 with 4x anti-aliasing enabled. This is around 3fps quicker than the HD 4830. The pattern was similar in our Crysis test, too, and by reducing the resolution to 1,440×900 we achieved a playable 30.3fps.
The 40nm manufacturing process should result in a cooler-running GPU, but it seems that ATI has already pushed the card to something approaching its limit. We had high hopes for its overclocking potential, and tweaked the card using ATI’s own OverDrive AutoTune tool, but we could only raise the GPU and memory speeds by small amounts, with performance gains of a handful of frames per second. Its heatsink became very hot to the touch when running our tests.
Like the other 4000-series cards, this one has two DVI outputs, either of which can be converted to VGA or HDMI with an adaptor. The onboard audio controller can output audio over HDMI without any additional hardware. The card uses a single slot in your PC, although the heatsink may block the slot below.
The graphics card market is very price sensitive, but the HD 4770 seems to be positioned just right. It’s a worthy replacement for the HD 4830, as it’s both a little cheaper and a little faster, but it’s hardly the exciting product we’d hoped for given the new technology at its heart. Despite this, it’s the best graphics card for playing games on a budget.
|PCI Express x16 2.0
|Slots taken up
|ATI Radeon HD 4770
|GPU clock speed
|640 stream processors
|Power leads required
|1x 6-pin PCI Express
|3DMark Vantage 1680
|Call of Duty 4 1680 4xAA
|Call of Duty 4 1440 4xAA
|Crysis 1680 High 4xAA
|Crysis 1440 High 4xAA
|one year RTB