I'm inclined to follow what you said, Bjorn. Looking into LVM cache and bcache and there's a lot of useful information. I noticed a lot more people leaning towards bcache, though. It seems simple enough to setup (relatively speaking), so what kind of configuration or tuning would be needed past that? If it doesn't end up working, I could always just return the drive to its previous state as an OS X drive, but I'd rather not.
I'm considering taking the 2 identical HDD's and re-raiding them into a 2TB RAID0 like I have on Windows. I use this as a scratch/cache disk for apps, it especially comes in handy for simulations. In an effot to remain consistent with what I already use, here's the setup I'm looking at:
250GB SSD = / and /home (coding projects or small media projects)
250GB SSD = Main work drive for projects
1TB HDD = Main Media drive (where I transfer older projects and host things like movies, etc) Projects will likely get compressed before going here.
2TB RAID0 = Cache disk for all apps and simulations. I would look into NVME drives, but their limited capacity don't warrant the swtich yet.
120GB SSD = bcache disk
A question about bcache: Can I use bcache for both the RAID array and the media drive? Would I have to create 2 partitions on the SSD, one for each backing device? Or should I exclude the RAID from this completely; I usually get upwards of 300MB read/write on it, and I can't think of why it would be read/written non-sequentially. One of the benefits I saw of bcache was that it ignored sequential reads or something like it, which would be super useful when reading media files and could reduce the wear of the SSD. This will be done on a completely clean system, all data will be dumped into dropbox before installation.