IDE64 Performance Comparison
This page sumarizes the results of the performance test program PerfMon
As you can see from the graph (shorter bars are faster) IDE64 is much more than 100 times faster than plain 1541 floppy drive. There is only one device for stock C64 with comparable performance. It is the CMD RamLink.
This graph (longer bars are faster) compares performance of the IDE64 with IDE64-DOS V.895, hard disk drive Quantum Fireball TM1280A (1.2GB) vs. CMD RamLink with 4MB RAM.
You can see the IDE64 is the FASTEST device for a stock C64 that's currently available (found out on Forever 4 thanks Soci/Singular and JTR from Protovision).
This graph (longer bars are faster) shows performances of the C64 floppy drives 1541, 1541 with the floppy speeder (build in the IDE64 DOS), 1581 and PC-Link. Parallel PC-Link is not as fast as an Serial PC-Link because Serial PC-Link uses powerful DUART RS-232 card based on 68C681 chip which increases the performance.