XFX Radeon HD 7950 Double D Black Edition 3GB (FX-795A-TDBC)
The third graphics card in this review comes from XFX. Although a lower-class product than the other two, the Radeon HD 7950 Double D Black Edition 3GB (FX-795A-TDBC) is no less interesting. As is typical of XFX graphics cards, it is packaged into an upright cardboard box with lots of information all over.
Besides documentation, the card is shipped with an HDMI-DVI cable, a CrossFireX bridge, a CD with drivers and utilities, an XFX badge, and a door tag.
There are no games included in the box. The product’s warranty period is 1 year and its retail price starts at $439.
The XFX Radeon HD 7950 Double D Edition looks exactly like the XFX R7970 Double Dissipation Edition we tested a couple of months ago:
It’s got the same steel-like casing, two glossy-black fans and a red edge with the word GHOST. Like the graphics cards from Gigabyte and Sapphire and also like the reference Radeon HD 7950, it is equipped with one dual-link DVI-I, one HDMI and two mini-DisplayPorts:
The XFX-shaped vent grid in the mounting bracket is a special feature of XFX products. The shape of the grid isn’t important for the employed cooler design anyway.
Everything’s standard in terms of the CrossFireX and 6-pin power connectors:
The PCB is black, copper interconnects standing out well against this background.
Like the Gigabyte card, the XFX Radeon HD 7950 Double D Edition boasts high-quality DURATEC components: solid-state capacitors and ferrite-core chokes.
The power system is built according to a 6+2+1 formula (GPU+PLL+memory), just like on the reference card.
The same CHL8228G controller is responsible for managing the power system.
The card’s Tahiti Pro GPU is clocked at 900 MHz in 3D mode, which is 12.5% higher than the reference card’s clock rate.
The GPU voltage of our sample of the XFX card is 1.031 volts in 3D mode and 0.949 volts in 2D mode when the clock rate is dropped to 300 MHz.
The card’s got 3 gigabytes of GDDR5 memory in twelve FCBGA-packaged chips from Hynix Semiconductor.
Labeled H5GQ2H24MFR T2C, the chips have a rated frequency of 5500 MHz and this is indeed the memory frequency of the XFX card. We can remind you that the reference Radeon HD 7950 has a memory clock rate of 5000 MHz and the reference HD 7970, 5500 MHz. The memory bus is 384 bits wide, providing a peak bandwidth of 264 GB/s. In other words, the XFX card is as fast as in terms of memory bandwidth as the reference HD 7970. The card drops its memory clock rate to 600 MHz in 2D applications.
The GPU quality level of our XFX Radeon HD 7950 Double D Black Edition is 69.9%:
We discussed XFX’s exclusive Double Dissipation cooler in our earlier review, so we’ll give you but a couple of photos here:
There is a generous amount of thermal grease on the GPU:
The heatsink with two 90mm fans is the same as before:
Let’s see how efficient this cooler is with the slightly pre-overclocked XFX HD 7950:
Auto fan mode
Max fan speed
So, the GPU is 74°C hot when the cooler’s fans are regulated automatically and… the same 74°C hot at the maximum speed of the fans. It’s because the fans were actually working at their maximum speed in the automatic mode, too. The card was quite noisy, but we’ll discuss the noise factor later on. Right now let’s check out its overclocking potential.
Our XFX Radeon HD 7950 Double D Black Edition was stable at a GPU clock rate of 1015 MHz (+12.8%).
The graphics memory didn’t fail until 7320 MHz, so we limited ourselves to 7280 MHz to be on the safe side. The overclocked GPU was 76°C hot at the maximum speed of the fans.
Then we increased voltage to 1.25 volts and made the GPU stable at 1100 MHz (+22.2% above the default clock rate of the XFX card and +37.5% above the reference HD 7950). Steadily lowering the voltage after that, we found that the GPU could be clocked at 1100 MHz even at 1.1 volts.
The GPU got as hot as 86°C at such settings, the fans roaring at 3560 RPM.
We wouldn’t recommend overclocking this card like that permanently. It would be a stress for the hardware as well as for your ears.