Disk slower in 755CX

[David Hite <dhite@mitre.org>]

Here's a weird one: I have a 755CSE and I just got a 755CX to replace it.
While transferring files from one machine to the other, I noticed that the
CX disk seemed to be a little slower than the CSE disk. Both are 810MB disks. 

I did a Norton sysinfo for the disks and came up with 12.4 for the CSE and
10.0 for the CX, confirming my subjective feeling that the CX disk was slower. 

So I tried switching disks. I put the CSE's disk in the CX, and vice-versa,
then ran sysinfo again. The disk in the CX was still rated at ~10.0 and the
one in the CSE was still rated at ~12.4. So I guess the slower speed of the
disk comes from the machine, but I don't understand why. I guess I assumed
that the 100Mhz CSE and the 75Mhz CX would have similar disk bus speeds, or
at least that the CX would not be _slower_ than the CSE, but that appears
not to be true. Has anybody else done a similar experiment? Are other
explanations possible?

David