(Optional, a whole number) How much a host's free CPU as a percentage of the host (relative) counts when automatic host selection looks for the "most available" host. Weights are relative to each other: only their proportions matter, so 1 and 1 mean the same as 50 and 50. Zero ignores the measure.

Every host gets a score between 0 (nothing free) and 1, the weighted average of four measures: free CPU in MHz, free CPU as a percentage of that host's capacity, free memory in MB, and free memory as a percentage of that host's memory. The host with the highest score wins. The two absolute (MHz, MB) measures are compared with the best of the candidate hosts, so the host with the most free MHz gets 1 for that measure; the percentage ones use each host's own capacity.

Raise this to favour the hosts that are the most idle by percentage, whatever their size.

If all four weights are zero (the default), the original ranking applies: the host whose busier resource, CPU or memory, is the least used by percentage. The build console log lists every host considered with its score, and why any host was ruled out.