Note: the following are preliminary considerations on putting together a small Linux cluster based on multiple "La Frite" SBC's.
General idea
The idea here is to put together a fully functional Linux cluster based on a small number of "La Frite" SBC's. While such a "personal Linux cluster" won't break any computing performance records, it will allow for the development, prototyping and testing of High Performance Computing (HPC) applications, benchmarks and system tools, for a relatively modest cost and with negligible impact on one's monthly electricity bills. This "personal Linux cluster" can also be used as a low-TDP AArch64 build farm.
Why the "La Frite" and not any other SBC?
Quite simply because the "La Frite" packs the most computing performance in the smallest volume for the least expense and with very reasonable power dissipation, among all 64-bit SBC's presently (Q4 2018) available. And the "La Frite" can boot Linux using PXE, which as we shall see, makes it an excellent choice for small clusters. You can check this excellent benchmarking initiative to see how the quad-core Cortex-A53 "La Frite" would compare with other SBC's in the case of a build farm.
Which is better for putting together a personal Linux cluster, the 512MB or the 1GB "La Frite"?
It really depends on the future applications you intend to develop and test on your personal Linux cluster. In most cases the 512MB "La Frite" will do fine, but you may want to invest the extra few $ to have 1GB of RAM per node.
Bill-of-materials (BOM) for a 20-core, 5-node personal Linux cluster based on "La Frite" SBC's
This is a tentative BOM for putting together a small personal Linux cluster based on "La Frite" SBC's. Shipping costs are not included.
| Item No. | Item | Quantity | $ Cost/Unit | $ Cost |
|---|---|---|---|---|
| 1 | 512MB "La Frite" SBC | 5 | $10 | $50 |
| 2 | 10A USB charger | 1 | $10 | $10 |
| 3 | Micro-USB power cable | 5 | $1 | $5 |
| 4 | 8-port Fast Ethernet Switch | 1 | $10 | $10 |
| 5 | CAT5E Ethernet patch cable, 1m or less | 5 | $1 | $5 |
| 6 | (optional) USB 2.0 key, 8GB or more | 5 | $3 | $15 |
| Total cost | $95 | |||
Yes, a 20-core 64-bit Linux cluster for less than $100!
Note that the USB keys (one per node) are entirely optional, since the "La Frite" nodes can boot the Linux kernel using PXE and access their root filesystems on the controller laptop/PC/workstation using NFS.