[Klathmon]

It sounds to me like they are testing it on slower machines (specifically slower hard drives), as they specifically call out one of the "smaller" optimizations as having a significant impact on machines with slower hard drives.

[foota]

It sounded to me like they were extrapolating though, "This resulted in a ~100ms improvement on a fast machine with an SSD but, since most of this work was I/O bound, we expect it to be even more noticeable on slower hardware." This in fact was where I drew the inspiration for my comment from.