The graphics card comes with 1 gigabyte of GDDR5 memory in eight FCFBGA chips on the face side of the PCB.
Manufactured by Elpida, the W1032BBBG-50-F chips have a rated access time of 5 nanoseconds which means a clock rate of 5000 MHz. However, the card clocks them at 4200 MHz, which is 200 MHz above the memory frequency of the reference Radeon HD 6870 but far from the chips’ rated frequency. Perhaps they can be overclocked even more. The memory frequency is lowered to 600 MHz in 2D applications; the memory bus is 256 bits wide.
Here is a summary of the Sapphire Radeon HD 6870 DiRT 3 Edition specs:
The Sapphire card can’t boast serious factory overclocking or a double amount of memory, so the only original thing we can found about it is its cooler.
The cooler has an aluminum heatsink with a copper base and two 8mm heat pipes.
The copper base is no thicker than 2 millimeters, so there are no grooves in it. The pipes are somewhat flattened (to enlarge the area of contact) and soldered to the base.
We can notice some soldering where the pipes contact the heatsink fins. The whole arrangement is high quality.
The cooler has two 9-blade fans set within a plastic frame:
The fans are manufactured by FirstD.
The speed of the fans is PWM-regulated automatically within a range of 1250 to 3250 RPM.
We checked out the card’s temperature while running Aliens vs. Predator (2010) in five cycles at the highest settings (1920x1080, 16x anisotropic filtering). We used MSI Afterburner 2.2.0 Beta 8 and GPU-Z 0.5.5 as monitoring tools. This test was carried out with a closed system case (you can view its full configuration in the appropriate section of the review) at an ambient temperature of 24.5°C. The default GPU thermal grease was replaced with Arctic MX-4.
Let’s see how efficient the cooler is.
When the cooler's fans are regulated automatically, their speed is 2070 RPM while the peak GPU temperature is 74°C. At the maximum speed of the fans the temperature wasn’t higher than 68°C. Both numbers are good, but not impressive. On the other hand, we are yet to check out how noisy the cooler is. We’ll do this right after the next card's description. Right now, let's see if we can overclock the Sapphire Radeon HD 6870 DiRT 3 Edition any further.
The clock rates of 980/4780 MHz are just what you can expect when overclocking a Radeon HD 6870. Alas, our GPU couldn’t notch 1000 MHz whereas the memory chips were not stable even at their rated 5000 MHz.
When overclocked, the card’s GPU got only 2°C hotter (to 76°) while the fan speed was 2180 RPM.
And that’s a very nice result.