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PCB Design

The PowerColor Bravo X700 seems to resemble the RADEON X700 PRO at first sight, but there are still some important differences. Particularly, it has two DVI connectors and a SiI1162 transmitter from Silicon Image that is responsible for the second DVI output. The elements in the power circuit are placed in a different way and the circuit itself includes more electrolytic capacitors.

The complexity of the power circuit is justifiable as this graphics card uses GDDR2 memory that consumes more power than GDDR3. Despite the number “2”, GDDR2 is in fact a version of ordinary DDR and, like DDR, works at VDD = 2.5V, but has a lower VDDQ (1.8V). GDDR2 memory works at higher frequencies than typical PC3200 modules, so its power consumption and heat dissipation are much higher. And these are the reasons why GDDR2 is rarely employed on modern graphics cards.

We know about three cases when GDDR2 was ever used: on ATI RADEON 9800 PRO 256MB, on NVIDIA GeForce FX 5800 Ultra and on GeForce FX 5700 Ultra (in the latter case the manufacturers soon gave up this memory type and replaced it with the more economical and cold GDDR3). GDDR3 traces its origin to DDR2, works at a 1.8-2.0V voltage (both VDD and VDDQ) and generates much less heat. We have no idea why PowerColor used GDDR2 in the reviewed product, but it is a fact that the memory they put on the PowerColor Bravo X700 is not of the best type possible.

The placement of the memory chips is unique, too. At least we haven’t seen a similar PCB layout on any other card. Like the RADEON X700 PRO, the PowerColor Bravo X700 carries eight 256Mbit chips on board that yield a total of 256 megabytes of graphics memory. The chips are placed in pairs on both sides of the PCB crosswise rather than along the edges, as usual. Again, it’s the first time we see this way of placing memory chips and we don’t know the reasons for using it.

 
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