^ Fair advice but not very specific, and will not apply to everything. Gam3r01 is right in that different games have wildly different CPU needs.
I'd argue that if we're even going to take Passmark seriously (which we shouldn't), I'd probably put the single-threaded cutoff at about 2000, which is approximately what a 6-7 year old Core i3 scores... which is still going to provide a very poor experience in some games. My i5 is getting a bit long in the tooth, and at stock speeds it's around 2100 / 7200.