WHS System Build: Power Supply

I started out by using a couple online power calculators in order to get an idea about the size power supply I needed. My requirements are pretty basic, the biggest power user would be the 12 drive capacity I wanted. Beyond that it was a single CPU with 4 sticks of memory on a regular desktop motherboard. I figured a simple memory card and an additional SATA controller. The Thermaltake Power Supply Calculator is where I started and it estimated I needed 477 watts. The Newegg Power Supply Calculator is more conservative (but simpler to use) and even though it could only go to 8 drives it suggested 496 watts. So I needed a minimum of a 500 watt power supply. Read more to find out what I picked.

Corsair AX 850 Power SupplyI covered the case I chose along with the cpu/ram/motherboard combination I picked for my Windows Hone Server Vail build. Now it’s time to talk about my choice of power supply.

I started out by using a couple online power calculators in order to get an idea about the size power supply I needed.  My requirements are pretty basic, the biggest power user would be the 12 drive capacity I wanted. Beyond that it was a single CPU with 4 sticks of memory on a regular desktop motherboard. I figured a simple memory card and an additional SATA controller. The Thermaltake Power Supply Calculator is where I started and it estimated I needed 477 watts. The Newegg Power Supply Calculator is more conservative (but simpler to use) and even though it could only go to 8 drives it suggested 496 watts.  So I needed a minimum of a 500 watt power supply.

I’m conservative when it comes to estimates so I’d be overestimating and starting my search at 750W.  Since I’d probably have a lot more power available than I’d be using after the initial surge to power up all those hard drives I’d want something that extremely efficient. I’d also want a quality power supply that would last through any server expansions and into my next build(s).

I spent some time going through the reviews at JonnyGuru.com among other sites. I eventually decided on the Corsair AX850 Power Supply. It’s pricey, coming it at just under $200 from most locations (Amazon or Newegg) with Newegg currently having a $10 mail-in rebate.

The JonnyGuru review gave the power supply a glowing review. As the name implies it’s a 850 watt power supply. Other features includes:

  • Rated 80 Plus Gold efficiency (although the JohnnyGuru test brought it in just under that.
  • The fan only spins after the temperature reaches a certain level which reduces the noise
  • Fully modular which was a plus for me as I’m looking to keep the build as neat as possible and only need power to the motherboard and the drives. I won’t be needing cable power to any cards.
  • The power supply comes with 12 SATA power connectors which meets all my needs so I won’t be needing any splitters.

I won’t know until I start the build, but the 600mm cable length for the power supply seemed as if it would be a stretch in my case. The motherboard has the power plug about as far away from the bottom mounted power supply as it could be so I ordered a couple extension cables to be prepared. I’ll want to be able to route the cable behind the motherboard.

The only downside was the price although in this case I think I’m getting a quality product that will last many years and into my next build. I suspect I could have saved $30 or so and gone with the 750watt power supply. I’ll put a Kill A Watt monitor on it to see what the power draw is after my build. I won’t have to worry about a power shortage, put hopefully I haven’t over-provisioned to the point of wasting power and  money.

This almost completes my parts list. I still want to add a SATA controller to get my 12 drive capacity but I won’t need that to start the build. I’ve got a few  misc. pieces such as cables and a NIC card. I shouldn’t be too long before I start the build and will find out whether or not I made good choices.

Any comments or suggestions about my choice?