You shouldn't actually need that much disk bandwidth to run something like a reddit though. 192 GB of RAM (which gaming motherboards can support) costs under $1

You shouldn't actually need that much disk bandwidth to run something like a reddit though. 192 GB of RAM (which gaming motherboards can support) costs under $1k and should be enough to keep several weeks worth of threads warm. On the other hand, a large thread might need to transfer ~100 kB, so at 10k requests/second, that's ~8 Gb/s. I can't find stats on how many page views/second they get, but I imagine it's more than 10k/s and less than 100k/s, so presumably somewhere between 10Gb/s and 80Gb/s you have more than you need for that use case.