Is it true that secondary IDE is slower than Primary? I have a brand new
Western Digital 120 GB 7200 RPM HD, and because I don't have a place on the
primary IDE, I unplug the (unused) CD-ROM and use the secondary IDE as the
harddrive connection.
I checked with "hdparm -tT" and the Timing buffered disk reads is horrible:
about 25 MB/sec. This is of course in linux single mode.
On my other machine, the same WD HD (80 GB) on primary IDE gives me almost
twice the troughput. I checked all options that can be enabled in hdparm to
be enabled (multcount, dma, 32-bit I/O) , so I ended up have all the same
options enabled for those 2 system, but the one with the HD in secondary IDE
has considerably slower I/O.
Anything that I might overlook? Any info is greatly appreciated.
RDB
--
Reuben D. Budiardja
Department of Physics and Astronomy
The University of Tennessee, Knoxville, TN
Hi Reuben,
Actually, the primary bus is considerably faster if it is a UDMA 66 or faster bus. This depends on the motherboard, but most recent motherboards have UDMA 66 or faster transfer rates and 133s are common. To use them you must use the 80 pin ribbon cable, rather than the standard 40. Usually the primary IDE connector is colored differently from the secondary on motherboards that support UDMA 66 or faster.
The Western Digital hard drive you have chosen should have an on-board 8MB cache, which also greatly increases access rates. I have two of those drive in my server and they are extremely quick, like almost SCSI speeds (~35 MB/sec).
The one I'm anxious to see is serial ATA, as I am told that the speeds exceed SCSI in most read/write operations. The Linux drivers are still beta, so I haven't begun testing yet.
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Tom Thomas S. Fortner Burleson, Texas thomas.fortner@xxxxxxxxxxxxx "but we preach Christ crucified..." 1 Corinthians 1:23 |
