AMD’s new Radeon HD 7750 and 7770: Benchmark Roundup

Although the benchmark-shattering Radeon HD 7970 and 7970 have occupied the bulk of our attention over the past few weeks, AMD hasn’t forgotten about those individuals who would like to get in on the new Southern Islands game but haven’t got half a grand to spend just on a video card. To that end, AMD has released the more down-to-earth 7750 and 7770 cards, aimed at the enthusiast who wants power, but not excess. Based on their new 28nm Graphics Core Next architecture, both these cards promise a range of features both to boost performance and to cut power consumption.

First, though, a short history lesson. When AMD launched their Northern Islands series of GPUs (more commonly known as the 6000 series), the midrange cards–the HD 6700 series–were just  rebadged 5700 series cards. As such, the 5700, initially released back in late 2009, has not had a proper upgrade until now. With such a storied and reputable predecessor, then, the 7700 series–codenamed Cape Verde–has quite a lot to live up to. Also, given the recent advances in integrated GPU technology and the resulting cannibalization of low-end GPU sales, AMD has decided to merely rebrand the Caicos and Turks cards (6400 and 6600 series, respectively) as 7000 series counterparts, making the 7700 series released today the very bottom of the 28nm Southern Islands GPU stack.

Cape Verde comes in two flavors, both sporting a 123-square-millimeter die packing 1.5 billion transistors and 10 Compute Units. All told, the 10 CUs give us 640 stream processors and 40 texture units. This full configuration will be available as the HD 7770, while and lesser 7750 has two of its CUs disabled, giving 512 stream processors and 32 texture units. Compared to the HD 7970’s Tahiti, Cape Verde has 31% of its big brother’s stream processors and texture units, half its ROP partitions, and a third of its memory bandwidth. While that may seem like a considerable drop, AMD has claimed that its goal for Cape Verde is playable 1080p performance, so single-screen gaming should be perfectly acceptable. Of course, if that’s still not enough, and the Tahiti monsters are just too dear for your budget, there’s still one GPU that hasn’t yet been released–the 7800 series, codenamed “Pitcairn.”

So what are reviewers saying about the 7700 siblings? Well, let’s start with the 7770. Officially called the Radeon HD 7770 GHz Edition in honor of its 1000MHz core clock speed, the full-fledged Cape Verde provides, according to AnandTech, “90% of the 6850’s gaming performance for 90% of the 6850’s launch price.” That is to say, in the year and a half that the Northern Islands GPUs have been on the market, AMD has improved its performance-per-dollar by exactly 0%. This sentiment is echoed by TechSpot, who compared the 7770 to NVidia’s GTX560 and declared that, despite the 7770’s 15% price advantage, the the GTX560’s performance gain–on average, 18% higher framerates–turns the tables in the green-and-black card’s favor. Furthermore, GTX560s can be found for as low as $170, effectively eliminating the only reason you would have to purchase a 7770 over it. Of course, a 7770 consumes 25W less power than either the HD 6850 or the GTX560 and offers DX11.1 support, PowerTune, Fast HDMI, and other new features, but none of these will provide the same performance boost as the straightforward power increase afforded by the two older cards.

The HD 7750, however, was more favorably received. In a comparison to a GTX550Ti, the 7750 delivered 2% lower framerates (small enough to be a rounding error), despite costing $20 less and consuming 30% less power. Its low profile design, lack of auxiliary power requirement, and commendable performance make it a very viable HTPC video card.

All in all, then, it seems that the HD7770, despite its reduced power consumption and expanded feature set, is still thoroughly spanked by the less-pricey 6850 as well as the comparably-priced but more powerful GTX560. We’re predicting a fairly sizable drop in price from its current $159 MSRP, although the 7750 seems to hold its own well enough that its $109 price tag seems justified.

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Sources: Anandtech, TechSpot, Tom’s Hardware