- Ability to host at least six SATA drives on a fast bus (i.e. motherboard southbridge, or expansion cards on PCIe)
- Low power (generally implies BIOS voltage controls)
- Gigabit network (2x would be ideal, especially with Intel chips, but not necessary)
- ECC RAM support
- Free PCIe slot for future upgrades
One popular NAS motherboard here on SPCR is the Gigabyte GA-MA74GM-S2. I have this motherboard. It's not bad, but there are a couple things that annoy me about it:
- No ECC support. In theory, AMD Athlon CPUs are supposed to support ECC (since the memory controller is on-chip), but it still requires BIOS support. The ga-ma74gm-s2 doesn't have any ECC BIOS options to suggest ECC is supported. (To be fair, this is conjecture, as ECC might be supported "behind the scenes".)
- The PCIe x16 slot is for video only. I tried using a 2 port SATA card in this slot, and the machine would reboot whenever data was written to a disk on this card. I contacted Gigabyte, and they explicitly said that the slot is for video only
- Four phase VRM. Since I intend to use the least-power CPU and/or undervolt/underclock, fewer VRM phases are better. Fewer phases mean lower power consumption
- Three phase VRM (can't use high-power CPUs over 95W)
- Explicit ECC options in the BIOS
- EDIT: both PCIe slots can be used with non-video cards (see follow up below)
- G.Skill F2-6400PHU2-1GBHZ (2 x 512 MB modules, 1 GB total)
- Boot drive: 8 GB Compact flash via PATA-to-CF adapter
- AMD Sempron LE-1250 CPU (G2 stepping)
- PicoPSU 120W w/8.5A EDAC power brick (from mini-box.com)
I went through the BIOS, and made the following changes:
- Set base CPU frequency to 200 MHz
- Set multiplier to x4.0 on the Biostar, and x5 on the Gigabyte (that's the lowest BIOS setting)
- Disabled sound and floppy
- Set memory to DDR-533
- Lowered GPU clock as low as possible: 200 MHz on Gigabte, 150 MHz on Biostar
- Lowered CPU voltage to 0.85 V
This is another good thread on the same topic (low power motherboards for NAS).
I also have a BE-2350 CPU that I might play with, if I have time. If anyone has any questions about any of this, I'm happy to (try) to answer them!
Thanks,
Matt