My current best guess as to ideal dedicated hardware for farming:
- Hardware on the FreeBSD supported hardware list (https://www.freebsd.org/relnotes/CURRENT/hardware/index.html)
- A low end Haswell or later CPU, preferably with ECC RAM support. These have really excellent idle power consumption, if you don’t care about power consumption then Ivy or Sandy Bridge CPUs are fine. Note that FreeBSD currently has poor support for Haswell CPUs.
- As fast and low latency a network connection as you can afford.
- Running FreeBSD 10 64 bit or later.
- ZFS as the filing system (ZFS - Wikipedia) with 4k alignment during config.
- As many hard drives as you can afford for the main ZFS backing. Ideally mirrored so they can self heal bit rot, but not strictly necessary.
- A small but fast SSD as the ZFS log intent device. This makes synchronous (fsynced) writes very fast. You don’t need it bigger than the largest amount of synchronously written data to occur at once, so even a 16Gb SSD is probably way overkill. Make sure you only allocate half of the device to the intent log leaving the other half trimmed empty, ZFS does a ton of writing and will wear out a SSD quickly if you give it the full device.
- As much (preferably ECC) RAM as you can afford for read caching by ZFS. 32Gb is probably enough. Some like to add another SSD for this, you can if you want.
That is probably a good best estimate for ideal dedicated farming hardware in terms of balancing power consumption, earnings and cost. I hope that helps.
Niall