Yes, the AAS CPU graph on the OEM Performance Page is correlated (R2 of .80) with the CPU core usage (CPU_COUNT=24 for Exadata X2).
AAS = 18.6 / 24 cores
= 77.5% CPU Util
ORACPUPCT = (78.95 * 24 cores) / 100
= 18.948 AAS
Pretty much the same
On the right side shows outliers that are caused by CPU Wait due to high wait IO due to kswapd or a bunch of processes blocked due to not enough CPU.
I'll detail more on CPU stuff at Oracle Closed World http://