HD 5750 & HD 5770 Review - PAGE 3

Specifications

The HD 5700 series is designed to give a great amount of gaming punch, for around the $150 mark. While it doesn't have the raw shader processor count as do the bigger brothers of the series, the HD 5800s, all of the GPUs share many of the same elements of architecture.

The secret to keeping the HD 5770 inexpensive is the same factor that made the HD 4770 such a bang-for-buck performer: fast GDDR5 memory is quick enough to keep games moving even with only the 128-bit memory interface. About two generations ago, the 128-bit memory interface was sporting on both Nvidia and ATI mid-range offerings -- but for the most part, it had proven incapable at delivering high performance for the demanding games of about 2006 onwards. But that was when GDDR3 memory was your only option; now, with GDDR5, 128-bit memory interface gaming cards are a reasonable proposition.

Nvidia and ATI have different methods of coming up with the shader count. For ATI, the HD 4700 series has 10 SIMD banks, 40 texture units, 64 Z/Stencil ROPs, and 16 color ROP units. Which is great news for fans of ROPs (Raster OPerators.)

While compared to Nvidia's line-up, the HD 5770 doesn't have an insurmountable advantage over Nvidia options around the same prices, when it comes to chip horsepower -- but  when you consider the costs of manufacturing involved, ATI is currently sitting a bit prettier. Nvidia will have to find success at 40nm in order to stay competitive with their coming generation of chips. 

 * denotes cumulative effective efforts coming from 2 GPU's (i.e GTX 295: two GPUs with 240 cores equal 480)

Overclocking

Many of you are probably interested in the overclocking potential of the HD 5700 series. The HD 4770's were capable of performing close to a HD 4850 level with the right amount of tweaking and a little luck. We were interseted to see what these cards were able to reach.

For the HD 5770, it was good news. Like the HD 5870, we are able to max out of the core clock in the CCC, to the top speed of 960 MHz. Whew -- not much under that golden 1 GHz mark; great stuff. With a robust cooler you might even be able to reach 1GHz with a HD 5770, which would be quite something. As for the memory, we ended our overclocking adventure at 1300 MHz. (Compare these numbers to the default speed of 850 / 1200 [core / memory] ).

We were hoping for great things from overclocking the HD 5750 -- it seems a likely candidate for high O/Cing potential. But we had to settle for merely really good, instead of incredible. What a let-down!  From a default speed of 700 / 1150, we were able to find stability in loops of Far Cry 2 with a core clock speed of 805 MHz, and 1195 MHz for the memory. The GDDR5 has little cooling to keep it stable so we would not recommend pushing the memory far on this card.  

Both of these video cards clocked over %10 higher, which is good. We look forward to getting some OC models in the future to see if the limits might be higher.

Keep in mind, that for our tests, we ran the fans at 100%. This is too loud for most people to put up with in regular use.