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Overclocking and Power Consumption: Knowing how a GPU performs at stock is only half the battle; we all know we can save a little cash if we can squeeze out more performance with some overclocking. Normally, I test out the built-in OverDrive feature in the Catalyst Control Center to see how close it comes to our final real overclock, and then follow up with RivaTuner if I need to exceed the imposed limits in OverDrive. In the case of the HD5770, the maximum limit is set to 960MHz on the core and 1445MHz on memory, and Auto-Tune took us to 950MHz/1435MHz. Actual testing showed this number to be right on, as the card was able to do some testing at a core of 960MHz, but would occasionally hang. Of course, there is no RivaTuner support yet for the new cards, so to do any further testing will require some patience. Some users have had some luck with AMD GPU Clock Tool, however I was not one of them.
Vantage Performance:
With a 12% core clock advantage, the overclocked HD5770 boosts its overall score by 10.4% in the Performance Preset. Vantage High:
For the High Preset, the overclock boosts the score by 11.4% Vantage Extreme:
At the Extreme setting, the score is increased by 11.9%. 3DMark06:
Finally, in 3DMark06, overclocking boosts scores by 5.3%. What it looks like here is that, with some good overclocking, the HD5770 will achieve about the same level of performance as the HD4890's stock clocks. Now, in terms of power, you will notice something in the above screenshot that we have not seen before. Need a hint? Look at the memory clock. The new generation of ATi cards now support dynamic memory clocking, which means that more power is saved by reducing the memory speed when the card is in idle mode. Let's measure the HD5770 against the HD4890 2GB and see what the difference is:
The Idle test is defined by sitting at the Windows desktop without any work being done. Load is defined as the end of three loops of the Crysis: Warhead bench at 2560x1200, 8xAA. Measurement is performed at the socket with a Kill-A-Watt meter. Here, the HD5770 consumes 56W less at Idle, which equates to 23%. At load, the HD5770 consumes 28% less, which translates to 95W saved. Not shabby at all. Having read many of the rumors and speculations posted around the web the last few weeks, I am sure that there will be some disappointment, after all, many sites were pumping up the HD5770 as a replacement for the HD4890, and the HD5750 as being on par with the HD4870. In reality, the HD5770 performs on the same level as the HD4870, which makes sense. When overclocked, it can touch the reference 4890's performance, but then, we all know the 4890 can be one heck of a monster overclocking GPU. In reality, the limitation lies within the 128-bit memory bus, and no amount of overclocking is going to overcome that. 4870s and 4890s will not be on store shelves for much longer, and it looks like the 5770 will directly replace them. With the HD5850s coming in at the $260 price point, and the HD5870s coming at $380, I can't help but think that the HD4890s will be sticking around a little longer at the $200 range, at least until another SKU comes along (5830, maybe?) or nVidia gets aggressive enough with pricing to force the 5850 down. I suppose it is all conjecture at this point, however what remains is that the HD5770 carries about the same price to performance ratio as the 4890, not greater like so many people were expecting. Of course, the power savings carries its own value into the equation, as does the support for DX11 and the advanced Blu-Ray audio codecs, as does the bundled DiRT 2. It's decreased size and heat are also vast improvements, and I am sure these things, combined with the TSMC 40nm process are doing wonders for ATI's profit margin. This means that when nVidia wants to put pressure on the market, ATI will be able to be more aggressive with price cuts as time goes on. That being said, the timing and execution of the new generation of GPUs is going exceedingly well for ATI. Other than some availability issues for the HD5850 and HD5870, it appears that the ATI is firing on all cylinders, and for now, nVidia seems to be on the ropes until its GT300 can be seen sometime next year. I think its safe to say that AMD has the rest of 2009 locked up; and I can't wait to see what new cards will be on their way. Pros:
Cons:
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