I don't know what you mean by "quantization". I guess you're asking to explain how they measure "performance", but that kind of thing often won't neatly fit in a title.

I do think the phrasing is weird, though. The performance may be improving, but it isn't the thing getting "faster" (e.g. responses to queries might get "faster"). And the dollars aren't getting cheaper; the performance is. "Performance per dollar" is a rate; it is not getting faster or cheaper. It should just say "Performance per dollar is increasing".