So if you want to Chia farm, I do think a smart choice to get started is an inexpensive external USB drive enclosure. Even one of the founders said as much:
All of that said, for my personal plotting I use a 2017 iMac and a 12TB Western Digital external drive on USB 3.0 for both temporary and final directory and I get a k32 about every 10 hours.
I had forgotten about this, but some people buy the enclosures, “shuck” them of the enclosure hardware, and take out the drives – which you can often get cheaper (!) as part of an enclosure bundle than you can when you buy the drive directly! If you are looking for inexpensive external drives, here’s a cool site that tracks the lowest prices for large drives offered as part of enclosure bundles:
Note that pretty much any modern computer will have a surprisingly fast connection via USB 3, but if you want to plot, I strongly recommend going for a Thunderbolt 3 enclosure, if your desktop or PC has that port. Here’s why:
Even ye old 2015 era computers will likely have a 5 Gbps (0.6 GB/sec) USB 3 port. It’s a very, very old standard. Newer computers will have a USB 3.1 10 Gbps (1.25 GB/sec) port, maybe even USB 3.2 20 Gbps (2.5 GB/sec) port, but you’d need to check the docs, or look for the little “10” marker near the port. Sometimes they’re a different color.
For a garden variety large external 4, 8, 12, 16 TB hard drive enclosure, the raw USB interface speed (and there’s always overhead!) isn’t too big a deal, because you’re gated by relatively slow spinny rust disk HDD speeds anyhow.
But if you want an external SSD for faster plotting, I’ve found that the quality of the interface hardware on the external enclosure matters a lot. Read reviews and look for the enclosures that have documented excellent performance under heavy workloads, both pure transfer speed as well as random read/write, etcetera. A lot of research turned up these Thunderbolt 3 enclosures:
Kind of pricey, but the lower cost ones do have terrible throughput, such as a Sabrent one that I liked a lot … maxed out at 1.6 GB/sec!
If you prefer bundled storage (not extractable, so if you wear the drive out, that’s a negative), the Samsung X5 and TEKQ Rapide perform very well in benchmarks.