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Inside the £1,000 Asus Mars

Identifying the hardware

On the side with the PCI-Express connector, the PCB has not only the usual GTX 285 hardware: GPU, 16 Hynix GDDR3 chips and NVIO chip, but also an NF200 chip too. This chip is present to feed both GPUs from the single PCI-Express x16 connection.

Just like previous dual PCB cards from Nvidia, the SLI connector is actually a tiny connection of two ultra-thin cables. Ths conenction is sufficient to connect the second PCB to the first, with the data flowing to the NF200 chip from the PCI-E connector and then getting distributed to both PCBs as that chip sees fit.

The two GPUs and the NF200 chip are are glued in, as well as soldered down, to withstand the heat from the relatively small heatsink.Without this belt-and-braces approach, the heat of the heatsink could expand the organic substrate and break the BGA balls underneath: it's a trick Microsoft used for the hot-running Xbox 360 GPU.

*Inside the £1,000 Asus Mars Identifying the hardware *Inside the £1,000 Asus Mars Identifying the hardware
*Inside the £1,000 Asus Mars Identifying the hardware *Inside the £1,000 Asus Mars Identifying the hardware
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Typically for a GTX 285 there is 6+2 phase power hardware, but Asus has reduced this to four-phase for the slave card and only five-phase for the master. Presumably this is to increase the power density, but then the Mars has a larger PCB than the standard GTX 295, so we're a little puzzled by Asus' VRM design. However, because two GPUs and an NF200 chip are being squeezed into such a small space, we're not surprised that our efforts to overclock the Mars didn't result in any more performance.

*Inside the £1,000 Asus Mars Identifying the hardware *Inside the £1,000 Asus Mars Identifying the hardware
Click to enlarge

Putting the card back together, the hardest part was connecting the two fiddly SLI cables that connect the two PCBs; there's very little extra length to play with to press them in. After that, it was just a case of working backwards, screwing everything back in (remembering to plug in the fan as well!).

*Inside the £1,000 Asus Mars Identifying the hardware *Inside the £1,000 Asus Mars Identifying the hardware
Click to enlarge

And there we have it! OK Asus, you can have the cards back now!

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