higher RPM drive slower?!

[zimu]

i just ran some tests on my new 40gig 5400RPM notebook drive, and realize that its transferring data slower than my older 30 gig 4700 RPM dirve! (i think i have the rpm's right).


why?! shouldn't the 5400rpm be a lot faster?! uncached speeds show it to be faster, but cached speed the 30 gig drive was faster. and they both have the same cache size.

anything i could use to diagnose potential problems/ transfer rates?

p.s. both drives had the exact same amount of data in them, and both were completely defragmented at time of test.

 

Mabey one drives cashe is faster than the other.

 

[thraxes]

perhaps the data density on the 30GB drive is higher? 1 30GB Platter in the drive as opposed to say 2 20GB platters in the other.

 

[Amorphus]

uncached speed seems to be all in line - the heads read from the platter faster in the case of the 5400rpm drive. methinks it's just a lower-speed cache in the 40gigger.

 

[johnjkr1]

maybe DMA isnt turned on?

 

[Abhi]

As john said.. check for DMA...

 

[zimu]

Originally posted by: Abhi
As john said.. check for DMA...

DMA is enabled

 

[helpmeout]

You don't say where you tested your drives, but did you use PC Pitstop? I have found that site often gives erroneous (IMHO) HD figures. I have a 40gig, 7200 RPM HD in the computer, and a 40 gig 5400 RPM drive in a USB 2.0 enclosure running off a USB2.0 port. The 5400 is very often reported with faster cache speed. The 5400 is just storage. Actually, I can't see a difference in drive speed, but possibly I blink, LOL.