View Full Version : [xubuntu] UDMA/33 using a 40-wire cable - correct drive read speeds? using hdparm

April 24th, 2009, 08:51 PM
I'm trying to work out if I'm getting the best speed I can out of my HDD as my system can be a little slow somedays... (I'm using hdparm to test the read speed)..

The system (xubuntu 8.04) is running from a 133x Compact Flash Card, connected by a 40-wire cable to the motherboard.

my dmesg states:

[ 24.610923] ata1.00: ATA-4: ELITE PRO CF CARD 4GB, 20071207, max UDMA/66
[ 24.610934] ata1.00: 7831152 sectors, multi 0: LBA
[ 24.610958] ata1.00: limited to UDMA/33 due to 40-wire cable
[ 24.627191] ata1.00: configured for UDMA/33
[ 24.627281] ata2: port disabled. ignoring.

I have found other people referencing a bug with what UDMA mode Ubuntu 8.04 recognises, and my hdparm -i for the drives states:

UDMA modes: udma0 udma1 *udma2 udma3 udma4
Drive conforms to: Unspecified: ATA/ATAPI-4

...and obviously it isn't managing to use UDMA4 / ATA4 - but am I to assume that as I AM actually using a 40-wire cable, that UDMA/33 is the best I will ever get out of it? Can a 40-wire cable go no faster? As I was thinking of replacing the card with a 266x speed one?

Also, my hdparm -tT dev/sda1 gives:

Timing cached reads: 356 MB in 2.00 seconds = 177.91 MB/sec
Timing buffered disk reads: 66 MB in 3.04 seconds = 21.74 MB/sec
Are these speeds reasonable - or is it likely to be causing things to run a little slowly?

Bit of a n00b question I'm sure - so apologies!

October 11th, 2009, 04:12 PM
You've probably worked this out already - but I just stumbled across this... What you need is an 80 wire IDE cable. Then you can go upto udma6 (if your controller supports it).