I don't know of any hard drives that can do a seek+read in 0.2 milliseconds. Keep in mind that the reads are distributed randomly - you're almost certainly goi

I don't know of any hard drives that can do a seek+read in 0.2 milliseconds. Keep in mind that the reads are distributed randomly - you're almost certainly going to need more than one disk if you have less than a terabyte of RAM for your datastore.