What's the fastest filesystem (and/or filesystem options) for a drive where I don't care about whether the data survives a crash or power-off, such as /tmp?
The data is a few hundred gigabytes so won't all fit in RAM. There is a mix of small and very large files (think HTML files and videos).
Is it best to just create a massive swap partition and use tmpfs? (Will that even work?) Or should I use ext2/3/4 or XFS or Btrfs? What are the optimization options I should use to turn off all the safety features and get the most performance out of the filesystem?
The disk is a HDD. An SSD is not feasible: This is a build server, so data is always being deleted and recreated, so the number of bytes written per day is a few times larger than the disk size. That means a consumer SSD is unlikely to last, and datacenter class SSDs designed for the high write load are too expensive.