Server using a lot less processing power?

My system specs are as follows:

2 Intel Xeon dual core 2.8GHz processors
6GBs DDR2 RAM
Dual 73GB 15,000RPM SCSI drives

Yesterday, running Bukkit version 250, I think, all four processing cores were bouncing back from 0 to 50% utilization. However, when I updated to Bukkit version 271, none of the cores went over 10% utilization. Also, the '[WARNING] Did the system time change, or is the server overloaded?' error thingy is coming a lot less. What's going on? Did Bukkit add CPU optimization or something? It's very strange.

 

I have a close setup to yours, dual opteron dual core 2.4GHz procs, 16GBs of DDR RAM, and dual 75GB SCSI drives. I still am seeing the can't keep up as I have one cpu pulled as it is being replaced. Still, it seems that it is utilizing dual core processors much better now. Can't wait to get the replacement CPU in.

 

They could have done that, or they could have simply fixed a bug that was eating up CPU needlessly.