ROBERT SAYRE wrote in a message to ROY J. TELLASON:

CA> I have read that if you mix a faster hard drive setup with a slower
CA> one the entire system will drop to the rate of the
CA> slowest hard drive.

RJT>  I had thought this to be the case too,  but it's not happening on
RJT> the linux box here,  where the system tells me that it's using two
RJT> different modes with two HDs that are in there...

RJT> Dunno about other platforms,  though.

RS>  My understanding is that the drives must be on the same cable to
RS> cause the slowdown.

RJT> They are...

RS>  Are they using PIO modes?

RS>  I'm guessing, but DMA modes may allow them to coexist without the 
RS> slow down. The info about the slow down was around before DMA was 
RS> available.

I'm not sure now.  I went looking in various places like /proc and /dev, 
and couldn't quite find the info I was looking for...

---