Last 5% of scans take forever

This seems to happen with every scan I run. The first 95% of machines scanned during any scan go by very quickly, however the last 5% take a rediculous amount of time. Right now I'm scanning 229 computers for one MS patch. The first 221 finished in about 15 minutes. The remaining 8 have been ticking by 1 every 10-15 minutes.

First, how can I see exactly which computers are taking so long?

Second, how can I alleviate this issue?

Thanks!