Typically, the quorum of successful machines doing WCG work units will all claim within about 15% of the average. (ie. the greediest might at most claim 130% of the amount the most generous machine claimed.) About the most divergent case I'd seen was for an HPF work unit where the range was 52-78 credits. (150%)

With AC@H, ranges are huge, such as 65-128 (197%). I guess that the way it hammers the hard drive writing checkpoint files 1000 times the size of other projects or the way it usually uses about 120MB RAM, but sporadically uses 3x this much, could significantly affect the credit system, since those activities are very different to a CPU benchmark, but I was wondering whether anyone with a good knowledge of the credit system could enlighten us?