|XFX Radeon HD5770 Video Card HD-577A-ZN|
|Reviews - Featured Reviews: Video Cards|
|Written by Bruce Normann|
|Tuesday, 27 October 2009|
Page 8 of 19
Overclocking the Radeon HD5770
Time was, overclocking was sort of a mysterious pastime of a small group of fanatical techies. Then the Intel Core2 Duo CPU hit the market and suddenly overclocking became less of a dangerous adventure and more of a birthright. In the video card world, it was not the arrival of overclocking friendly hardware that broke the ice, it was software utilities. They were supplied initially by third parties, then by the card vendors themselves, and now they come direct from the GPU manufacturer. For the first couple years, some had pretty awful interfaces and some didn't work too reliably, but these days the software from all three sources is of decent quality. I've reviewed the ASUS iTracker and msi products and they were both useful, and there's always the old stand-by, Riva-Tuner.
After reviewing my options, since XFX does not publish their own version of an overclocking utility for the new ATI 5xxx series of cards, I used Catalyst Control Center supplied by ATI, which works with every 5xxx series card. It doesn't allow the user to change GPU voltage, but it does have a fan control setting integrated in the application. I bumped the fan up to 100% at the beginning; better to explore the overclocking limits with all available cooling than to overcook the card while testing. There is an auto tune feature included, but I'm the impatient type, who likes full control, so I just dove right in and started cranking things up.
One of the anxious moments every overclocker has, is when the CPU, GPU, or memory locks up or starts spitting out random bits. The second anxious moment follows soon after, when it's time to restart the system. Especially with video cards, because they don't provide access to BIOS screens during POST and boot sequences. Most cards don't even have a way of resetting the BIOS, with a hardware jumper or otherwise. So, there is a possibility of turning that shiny new hunk of high tech into what is known in the industry as a "brick". Fortunately, although I crashed the XFX HD5770 several times while pushing it over the limit, it rebounded each time and asked for more....errr, less. Eventually the XFX HD5770 and I came to the conclusion that a 930MHz GPU clock and a 1250 MHz memory clock would be stable in all gaming and benchmarking situations. I had hoped for a bit more speed on the memory, but I think a few extra millivolts are required, and that capability is not currently available.
Leaving well enough alone is NOT the way most gamers and computer enthusiasts think, it's more like, "If it ain't broke, crank it up some more." So, we did that already, what now? The answer for the last several years has been, "Buy another one and hook ‘em together." CrossfireX and a spare HD5770 came to the rescue, and the combination did not disappoint. The 5770 scales very well in CrossfireX, and the installation and setup could not have been any easier. Once the system was running with one HD5770, I shut it down, plugged the second card in, attached the flexi-bridge, and restarted. Once Windows started up, Catalyst Control Center popped open and informed me that I had two GPUs running in CrossfireX, and asked if that was alright. I said yes; who wouldn't? From that point on, it was seamless, and the performance was amazing, even with stock, reference clocks. Once you see the results, I think you'll agree that this is a giant killer, in the ATI tradition. Remember the HD4770 in CrossfireX?
Now we're ready to begin testing video game performance on these video cards, so please continue to the next page as we start off with our 3DMark Vantage results.