The server runs 6 Western Digital 3TB green hard drives. They are quiet, cheap, run cool, and have sufficient speed for my storage needs. I also installed an LG Bluray combo drive into the optical slot, and a OWC 60GB SSD into the slot underneath the optical bay.
The motherboard has only 4 SATA connectors and I needed to plug in 8 drives. I needed a SATA card. This page gives a nice overview why you do not need an expensive RAID card for a ZFS-based system. I needed a 4 port HBA card that would work with Mac OS X. Officially, the only computer where you would use such a card is a Mac Pro and Mac Pros already have as many SATA ports as hard drive slots. The market for Mac compatible HBA cards with internal SATA connectors is very small and only a few cards are available. One of them is Sonnet Tempo. It is quite expensive though. I took a gamble and bought HighPoint Rocket 640L for about a third of the price of the Tempo. It is not officially supported by HighPoint as a Mac card, but it’s twin 644L that has 4 external SATA connectors is supported. It turned out I was lucky! The card works with Mac OS X out of the box and I could even boot from it.
The CPU is rated for 95W of power. The drives are rather efficient, using around 6W on peak. The total power consumption of the system is well below 200W. Finding a good inexpensive PSU proved to be a challenge. Finally I ended up with SeaSonic S12II 380W. It is 80 Plus Bronze certified and has very positive reviews around the web. There are a few issues with the supply, though. Firstly, it’s Bronze certified and you can get platinum certified PSUs now, which produce from one half to one third less heat at the server power levels. Less heat means less work for the cooling system and less current draw from the wall. These PSUs result in quieter and more efficient systems. Alas, they were not available when I was building the system. The second problem is that it is not modular. It means all the wires are firmly attached to the box and you have to deal with the wires you are not using by finding a place to stuff them inside the case. The place is not easy to find in a case that small. I wanted to put in a modular PSU. I even had my eyes on Seasonic 400W fanless PSU. However, it looks like that most of the modular PSU are also long: 160mm. The case is rated for 140mm long PSU. You can put in 150mm long one, but 160mm long PSU is very tight fit and the cables are likely not going to bend well.
Finding a CPU cooler was interesting as well. The distance between the PSU and the motherboard is about 110mm. You cannot put a tower heatsink in that space. Reading the Silent PC Review articles I found a number of good heatsinks that would fit the case. It looked like Noctua NH-L12 would fit and provide some exceptional cooling performance. I looked over the compatibility page on the Noctua web site and found out that the cooler block PCIe slot on the Intel board. I needed that slot for the HBA card. I got one of the other coolers in that list: Scythe Samurai ZZ.