Since iTunes isn’t thread optimized, it doesn’t benefit from the Atom 330’s additional core.
Something similar happened with the Lame MP3 encoder: it doesn’t scale on the dual core.
Cinebench graphics rendering performance almost doubles on the Atom 230 dual core.
WinRAR shows a nice performance increase when compressing files with WinRAR. The increase is still small, though.
WinZIP is not thread optimized, hence is takes the same time to process our workload.