Sapphire HD 4770 Reviewccokeman , ClayMeow - May 31, 2009
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The Sapphire HD 4770 is slightly smaller than the average performance video card. It is designed for use in a 16x PCIe slot and is PCIe 2.0 compliant. Instead of a single slot cooling solution, the HD 4770 comes with a large aluminum heatsink and takes up the space of two expansion slots. Quite different from the reference design. The back side of the red PCB contains no memory chips.
The front end of the HD 4770 contains pretty much standard fare when it comes to display connectivity, with two Dual-Link capable DVI ports and an HDTV output. HDMI is supported through the supplied DVI to HDMI adapter. The mounting bracket contains ventilation slots to allow some air to to be discharged out the back of the chassis instead of discharging it all inside the case. The rear end of the HD 4770 holds the 6-pin PCIe power connection and a flat heatsink over the power regulation circuit.
Cooling the HD 4770 is the job of the copper-colored aluminum heatsink. The cooler only directly pulls heat from the RV740 core instead of the standard reference solutions that cool the memory, GPU core and voltage regulation components. The fan contains nine fins and is inaudible over the rest of my case fans when the drivers are controlling the fan speeds. When the fan speed is pushed to 100 percent you can hear it, but it is not nearly as loud as the reference design. Load temperatures are quite acceptable with this cooling solution at 50 degrees Celsius under load with the fan at 100%. Drop the fan speed down by letting the driver control the fan speeds and you end up at 60 degrees Celsius. Both pretty reasonable. The HD 4770 is Crossfire X capable and can be used in up to a four-card Crossfire solution with the appropriate motherboard.
Once you pull the heatsink off, you can see just how small the RV740 core really is. The RV 740 GPU is packed full with 826 million transistors and 640 shader cores and is the first GPU based on the 40nm process manufactured at TSMC. The memory ATI chose to use on the HD 4770 is GDDR 5 manufactured by Qimonda and is rated for operation at 1000MHz. The GDDR5 memory is 512MB in size and runs though a 128-bit bus. The extra bandwidth allows for more memory bandwidth than GDDR3 at a comparable speed. Clock speeds come in at 750 MHz on the CPU and 800MHz on the GDDR5 memory.