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PCB Design

PowerColor’s product is big. It is a mere 1 millimeter shorter than the longest reference card, the 305-millimeter Radeon HD 6990. Well, its PCB is actually only 294 millimeters long while the rest of its length is due to the cooler’s plastic casing.

The Radeon HD 6870X2 isn’t extraordinary in terms of its other dimensions (38 x 111 millimeters) if you don’t count in the thick copper heat pipes sticking out of the cooler’s heatsink. Take note that some of the memory chips are installed on the reverse side of the PCB.

The graphics card has two dual-link DVI connectors, one HDMI, and a couple of mini-DisplayPorts (version 1.2).

There are plastic caps on the card’s connectors to protect them against dust. The rest of the mounting bracket is a vent grid for exhausting the hot air out of the system case.

You can find one CrossFireX connector and two 8-pin power connectors on the PCB.


As we know, the reference AMD Radeon HD 6870 has a peak power draw of 151 watts, so the dual-chip card is going to require more than 300 watts. PowerColor recommends a 600W or higher PSU for a computer with a Radeon HD 6870X2.

The cooling system is fastened with screws around the GPUs. We undid the screws to have a closer look at the PCB.

The two Barts XT chips are turned around by 45 degrees. Each is surrounded by four memory chips (four more are on the reverse side of the PCB). You can also see a switch chip in between the GPUs. The card is fitted with a 13-phase power system and features high-quality components (the so-called Platinum Power Kit). The ferrite chokes and the Texas Instruments 59901M DrMOS packs (driver and MOSFET combos) are expected to ensure stable operation of the graphics card throughout the entire service life.

The power system is managed by two CHiL Semiconductor CHL8214 controllers.

The two identical Barts XT chips were manufactured on 40nm tech process in Taiwan on the 46th week of 2010.


Each chip has 1120 unified shader processors, 56 texture-mapping units and 32 raster operators. In 3D applications they are clocked at 900 MHz and have a voltage of 1.172 volts. In other words, this card uses the same GPUs as you can find on the majority of ordinary Radeon HD 6870s. In the power-saving mode the GPU clock rate is dropped to 100 MHz and the voltage to 0.95 volts.

The Lucid HydraLogix 200 (LT22102) chip you can see between the GPUs is revision A1 and supports up to 48 PCI Express 2.0 lanes. Besides linking the GPUs in CrossFireX mode, it allows you use the dual-processor card together with Nvidia-based products (you’ll need to install the HydraLogic driver for that).

As opposed to most AMD-based graphics cards that use Samsung or Hynix memory chips, the PowerColor Radeon HD 6870X2 comes with GDDR5 memory from Elpida. The chips are marked as W1032BABG-50-F.

Their rated access time is 5.0 nanoseconds, which means a clock rate of 5000 MHz. The card’s actual memory clock rate is 4200 MHz, the same as with the reference Radeon HD 6870. There is a total of 2048 megabytes of graphics memory on board but each GPU can only access 1024 megabytes. The memory bus is 256 bits wide.

GPU-Z doesn’t make it clear that we’re dealing with something other than an ordinary Radeon HD 6870.

The line “ATI CrossFire = Enabled (2 GPUs)” provides a hint, but you can just as well suppose that there are two separate Radeon HD 6870 cards installed in the system. :)

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