As for the cooling systems, the Radeon HD 7770 GHz Edition is equipped with an aluminum heatsink and a black fan under a plastic casing:
The Radeon HD 7750 has a flat vapor chamber with a 60mm fan and some fins at the sides. It’s manufactured by NTK Limited.
Considering the low heat dissipation of both cards, these coolers seem to be quite sufficient for the task.
We run Aliens vs. Predator (2010) in five cycles at the highest settings (1920x1080, with 16x anisotropic filtering and without antialiasing) to check out the temperature of the tested cards. We used MSI Afterburner 2.2.0 Beta 15 and GPU-Z 0.6.0 as monitoring tools. This test was carried out with a closed system case at an ambient temperature of 25-26°C. We didn’t change the cards’ default thermal interface.
Unfortunately, our traditional method didn’t work with the Radeon HD 7750 because Aliens vs. Predator (2010) wouldn’t start on it for some reason. However, the card’s temperature was no higher than 62°C during other tests. As for the Radeon HD 7770 GHz Edition, here’s its temperature:
Automatic fan mode
Maximum fan speed
With its fan regulated automatically, the peak GPU temperature of the AMD Radeon HD 7770 GHz Edition was 72°C at a fan speed of 2010 RPM. When the fan was rotating at its maximum 4730 RPM, the temperature wasn’t higher than 64°C.
Then we measured the level of noise using an electronic noise-level meter CENTER-321 in a closed and quiet room about 20 sq. meters large. The noise-level meter was set on a tripod at a distance of 15 centimeters from the graphics card which was installed on an open testbed. The mainboard with the graphics card was placed at an edge of a desk on a foam-rubber tray.
The bottom limit of our noise-level meter is 29.8 dBA whereas the subjectively comfortable (not low, but comfortable) level of noise when measured from that distance is about 36 dBA. The speed of the graphics card’s fans was being adjusted by means of a controller that changed the supply voltage in steps of 0.5 V. We’ve included the results of a reference AMD Radeon HD 7850 into the next diagram:
The reference cooler of the Radeon HD 7770 GHz Edition turns out to be louder in the automatic mode than the far-from-quiet cooler of the reference Radeon HD 7850. Alas, reference cooling systems are generally noisy and only comfortable in 2D applications. As for the Radeon HD 7750, its cooler lacks a tachometer, so we can’t build its noise level graph. However, we could measure its peak noise at 12 volts: 58.8 dBA. Its minimum noise was 31.4 dBA at 3 volts.
The AMD Radeon HD 7750 behaved oddly during our overclockability test, too. Our testbed would hang up as soon as we tried to change the graphics card’s clock rates. Considering that other reviewers could overclock such cards to the level of the HD 7770 or even higher with the same software and drivers, we suspect it’s just a problem of our specific sample. So, we have to postpone this test until we get an off-the-shelf sample of that card.
As for the Radeon HD 7770 GHz Edition, we could overclock its GPU from 1000 to 1170 MHz (+17%) and its graphics memory from 4500 to 6280 MHz (+39.6%).
Further overclocking would require increasing the voltage of the GPU chip and this would call for a better cooler since the temperature of the overclocked Cape Verde XT was as high as 82°C.
Then we measured the power consumption of computer systems with different graphics cards using a multifunctional panel Zalman ZM-MFC3 which can report how much power a computer (the monitor not included) draws from a wall socket. There were two test modes: 2D (editing documents in Microsoft Word and web surfing) and 3D (the benchmark from Metro 2033: The Last Refuge at 1920x1080 with maximum settings). Here are the results:
The systems with the new cards from AMD indeed consume less power than the systems with the other graphics cards we’re going to benchmark today, although the difference isn’t large. A 450-watt power supply is going to be enough for every configuration, especially as our testbed is equipped with a well-overclocked six-core Intel Core i7-3960X Extreme Edition.