AMD Radeon HD 7770 review

When we reviewed the Radeon HD 7970 and HD 7950, we said AMD’s 28nm architecture was promising but expensive. We’re pleased, therefore, to report that the next release comes with a much more palatable price: the Radeon HD 7770 should launch at around £125 inc VAT.

It also has a 1GHz core clock, which is a highly impressive figure, even if the rest of the specification is more reserved. There’s 1GB of GDDR5 RAM clocked at 1,250MHz, and only 640 stream processors – down by 160 from last year’s HD 6770 – which means ten Graphics Core Next clusters, rather than the 32 included in its top-end cards.

Our benchmarks returned middling results. An average of 31fps in our 1,920 x 1,080 Very High quality Crysis test is playable, but it’s only 4fps better than the HD 6770, and 4fps slower than the HD 6850. There’s a similarly small gap in Crysis 2, with the HD 7770’s 30fps average in the Very High benchmark a mere 5fps more than the HD 6770.

At 1,920 x 1,080 and Very High quality in Just Cause 2, the HD 7770 ran at 47fps, 8fps faster than the HD 6770, and the same gap was replicated in DiRT 3. Our final games test, the blockbuster Battlefield 3, saw the gap narrow: the HD 7770 averaged 38fps at its highest settings and 1,920 x 1,080, with last year’s card 4fps behind.

It isn’t groundbreaking, then, but it did perform well in our thermal tests. Our test rig consists of an Intel Core i7-3960X processor, 8GB of RAM and an SSD, and when the card was pushed to its limits the whole machine drew 171W from the mains. That’s a huge reduction on the HD 6770, which required 251W. A peak temperature of 66°C is nothing to be concerned about either, and it’s hardly an imposing physical specimen: it has a dual-slot cooler, but needs only one six-pin power plug.

Good power draw only goes so far, though. It isn’t a big leap forward from last year’s hardware in performance terms, and it’s only just capable of topping 30fps at 1080p in the latest games, so the £125 price looks simply too high. For only a few pounds more you could get an HD 6870, which will blow this card away in any benchmark. Several cheaper cards also remain faster, which makes the HD 7770 a tough sell until AMD cuts its price.

Author: Mike Jennings