hdparm decreases performance
 

I ran hdparm -tT /dev/hda on my system with the following results:

Timing buffer-cache reads: 128 mb 0.89 sec = 143.82 mb/sec
Timing buffered disk reads: 64 mb 1.69 sec = 37.87 mb/sec

After reading a couple post and the man pages I tried the following:

hdparm -X34 -d1 -u1 -m16 -c3 /dev/hda

After running hdparm -tT /dev/hda again I now I get the following:

Timing buffer-cache reads: 128 mb 0.97 sec = 131.96 mb/sec
Timing buffered disk reads: 64 mb 5.30 sec = 12.08 mb/sec

I'm new to the Linux world but this does not seem like an improvement to me. Am I missing something or did I do something wrong?

Thanks in advance for the help.

buddhahat

P.S. - I'm running RH 9.

turning dma on (d1) is typically a big improvement if it was previously off.
did you check to see if it was off first ?
I reckon the other switches are going to be minor speed improvements in comparison, which would reflect what you're seeing.