That old Apple could (with a tail wind) almost manage a theoretical 0.5Mb of memory bandwidth per second; while the P4/i850/RDRAM combo does not reach the theoretical 3.2Gb/sec bandwidth, I've measured almost 1.8Gb/sec... memory bandwidth wise the performance is almost 4,000 times faster than the old Apple.
FULL STORY @ CPUREVIEW (http://www.cpureview.com/rev_p4-2GHz_a.html)
