to quote a wise man:
QUOTEthe rating means it is comparable to the AMD Thunderbird processors of the past, which had about equal performance to that of intel counterparts of the same speed. So 2500+ means it would perform at the level of a Thunderbird if it were at 2.5ghz and around that of a P4 @ 2.5.
This was mainly so buyers wouldnt be completely sucked in by Intel having 2.5 where AMD had 1.8, even though they have around the same performance. But now that Intel is using the 3xx, 5xx abd 7xx... AMD has the bigger numbers to woo the unenlightened public. W00T!
That A64 would run better than the P4 in most areas however