On Sunday August 10 2003 06:21 pm, Joeb wrote:
> Just to add to this, if he's using /dev/hda and /dev/hdb aren't
> they both on the same IDE controller on most systems? Since IDE
> can only write to one drive at a time per controller, improved
> performance would result in using the secondary IDE controller.
> To further complicate it, since they're both on the same
> controller (and cable) and one is UDMA 133 and the other UDMA
> 100, the fastest they will go is 100 and maybe only 66 because of
> the mismatch (although I'm not positive on the 66 part).
> Finally, I believe Windows is caching it's writes which will
> speed things up, at the expense of safety.
>
> Joeb
There's two parts involved, the drive firmware (controller
interface) and the controller on the motherboard. So unless you've
got separate PCI controller cards, all the drives use the one
controller, whether they're on the same cable or not. What is to be
avoided is putting a CD drive and HDD on the same cable. In any
event, no matter the number of controller cards you might have,
they all use the one old and tired 33mhz PCI bus. There's a new PCI
spec comin, PCI eXpress with a 66mhz bus. Like the AGP gimmick tho,
it only marginally (+5%) improves performance.
>[root /tom] $ hdparm -tT /dev/hd[ab]
>
>/dev/hda: (ata/133, udma6)
> Timing buffer-cache reads: 1232 MB in 2.00 seconds = 616.00
>MB/sec
> Timing buffered disk reads: 140 MB in 3.00 seconds = 46.67
>MB/sec
>
>/dev/hdb: (ata/100, udma6)
> Timing buffer-cache reads: 1252 MB in 2.00 seconds = 626.00
>MB/sec
> Timing buffered disk reads: 122 MB in 3.02 seconds = 40.40
>MB/sec
Both hda and hdb are on ide0. I have a cdrom and a burner on
ide1. BTW I've got a week old motherboard. Aopen AK77-400 Max/n,
KT400a chipset, IDE controller. It has 3 ide ports, ide0, ide1,
ide2 and a Serial/ATA port. So I could'a separated the HDD drives,
one to a cable (ide port). But I knew there's no point in that. I
believe the hdparm numbers back me up on that opinion ;) OTOH,
hdparm spits out burst numbers. In the real world I get about
20mb/sec transfers, ReiserFS to RieserFS, whether just moving files
on the same HDD, or hda to hdb.
I didn't wanna try separating the HDD's. When I installed the
new mobo/cpu/ram, I configured the ide's just as they were on the
old mobo. So when I booted up for the first time, my existing
Mandrake 9.2 install found the new onboard NIC, and then went on
like nothin was amiss. If I had Windoze, I'd still be installing
new drivers ;) The latest cooker 2.4.22 kernel has support for the
Serial/ATA port, but I don't have a S/ATA drive to try out.
--
Tom Brinkman Corpus Christi, Texas
Want to buy your Pack or Services from MandrakeSoft?
Go to http://www.mandrakestore.com
