Folding Rig May 2010

In line with the article educating us as to what makes the perfect folding farm, we've opted for a range of the best value components for folding. Nothing really changes this month and we expect this to stay the same for a few more months until mainstream Nvidia 4-series cards arrive and/or the Folding client finally gets an update for Radeon HD 5000-series graphics cards.

 Folding Rig
 ProductUK Price (inc VAT)US Price (ex tax)
Graphics Card(s)4 x Nvidia GeForce GTS 2504 x £954 x 110
CoolingAntec Big Boy 200mm fan£20$20
MotherboardMSI 790FX-GD70£135$125
CPU2.8GHz AMD Athlon II X2 240£45$55
Memory2GB 1,333MHz DDR3£45$110
PSUAntec TruePower New 750W£100$115
CPU Cooler (UK)Akasa AK-876£15NA
CPU Cooler (US)Arctic Cooling Freezer 64 Pro(£15)$30
Storage (HDD)160GB SATA£30$50
 Overall Price:£770$860

We can still buy four GeForce GTS 250s and the price-for-ppd output is very good. They are perfect for either getting started with a couple, or adding to a farm that needs to grow. And don't forget... every farm needs to grow!

Be careful for the 'green' cards - they maybe undervolted and consume less power, but they're also underclocked so generate less ppd. They could actually be less efficient for our farm's needs.

The Athlon II X2 240 is sufficient to drive data to all four cards - the CPU doesn't need to do that much in reality, and if you're looking for something slightly lower wattage (remember it won't be at full load, so not reaching the TDP) then you can pay more for a energy efficient Athlon II X2 240e, or simply experiment with undervolting a normal Athlon II.

Our favoured motherboard is still the MSI 790FX-GD70, and the recent AMD8-series chipset launches haven’t shifted our opinion. We've used 2GB of the cheapest branded memory we could find, as there's no gain from fast and expensive memory when folding. In fact, a single stick of 2GB DIMM of 1,333MHz DDR3 is fine (we'd have opted for 1,066MHz, but couldn't find any in stock). To cut power consumption, you might consider using low voltage memory, such as a Kingston LoVo kit or some 1.35V OCZ Low Voltage memory but weigh the extra cost of the kit against the power savings before ordering, and also check that your motherboard allows you apply low memory voltages.

We've forgone the case too, because it's almost impossible to find one that fits four dual-slot graphics cards. In place of a case, we've opted for just a simple solution: one huge fan. Sit the 200mm Antec Big Boy on top of the graphics cards and it should stop them roasting to an early death. We've used this setup in our own labs with seven GeForce 9600GTs in a single Asus X58 WS motherboard and it's worked perfectly and continuously for almost a year now. If you do have a case to recommend us, please let us know!

A cheap 250GB hard drive from the usual suspects will suffice for an OS, since not much storage is needed - simply the OS and small Folding programs are needed. Using an SSD won't cut much from your power bill, so don't bother with one.

We've opted for the Antec TruePower New 750W as power provider, given how excellent the 650W was, however the Seasonic X-750W will be more efficient for its 80Plus Gold rating, so it's also worth considering. For the £45 price difference, that's half way to another graphics card but overall efficiency and reliability should certainly be considered, because since the system is sitting at full load all day every day, it will rack up the savings on the electricity bill.

Finally, drop on the same Akasa AK-876 or Arctic Cooling Freezer 64 Pro that we also used in the Affordable All Rounder PC for ample cooling. If you want to save a few quid, the reference AMD cooler will suffice - those graphics cards are likely to be pretty loud anyway, so noise isn't a huge concern.
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