Promise PDC20276 in ATA133 mode: High CPU usage?

Hello,

I've got a GA-7DXR+ that has an onboard Promise PDC20276 (MBUltra133)
controller. It can be set for either RAID mode or ATA133 mode in the
BIOS.

When in ATA133 mode, I've noticed that the CPU usage is very high when
copying a large test file from a drive on it to a drive on my normal
onboard IDE controller. According to the Win2k task manager, it's about
80% CPU usage, with nearly all of that Kernel time.

In a older thread, somebody recommended using the controller in RAID
mode with just the single drive, using the Promise RAID driver. This
actually did fix the CPU usage problem for me, but I'm concerned that I
cannot access the drive's SMART data in this configuration. And my
Acronis TrueImage recovery CD seems to be somewhat unstable when reading
an image off of the drive on the 20276. (At least in RAID mode...
haven't gotten around to testing ATA133 stability)

I'm currently using the 2.00.1020.41 version of the MBUltra133 driver.
A user in another old thread mentioned that he was using the "20"
version of the driver without any abnormal CPU usage, but I could not
find that version anywhere.

Is anybody here using their PDC20276 in ATA133 mode without any
excessive CPU usage? If so, what's your secret?

Would I be better off getting a PCI IDE controller and using it instead?
Any models to avoid? (Promise??)

thanks!
-WD

Will Dormann wrote:
When in ATA133 mode, I've noticed that the CPU usage is very high when
copying a large test file from a drive on it to a drive on my normal
onboard IDE controller. According to the Win2k task manager, it's about
80% CPU usage, with nearly all of that Kernel time.

Just a follow up to my original post...

I tried setting up the PC so that the two hard drives were both on the
onboard IDE controller (different channels), and the CPU usage was
pretty similar. I thought that the CPU usage should be lower because
of DMA and such, but I guess I was wrong.



And my
Acronis TrueImage recovery CD seems to be somewhat unstable when reading
an image off of the drive on the 20276. (At least in RAID mode...
haven't gotten around to testing ATA133 stability)

ATA133 mode has the same problems. I think it's an issue with linux
and the PDC20276 chip.


-WD

i think its more likely an issue with IDE RAID.. they all have high CPU
util, no matter what OS.

Now SCSI Raid has virtually no CPU overhead which is why real servers use
SCSI and not IDE raid.

NuTs

"Will Dormann" wrote in message
...
Will Dormann wrote:
When in ATA133 mode, I've noticed that the CPU usage is very high when
copying a large test file from a drive on it to a drive on my normal
onboard IDE controller. According to the Win2k task manager, it's about
80% CPU usage, with nearly all of that Kernel time.

Just a follow up to my original post...

I tried setting up the PC so that the two hard drives were both on the
onboard IDE controller (different channels), and the CPU usage was
pretty similar. I thought that the CPU usage should be lower because
of DMA and such, but I guess I was wrong.



And my
Acronis TrueImage recovery CD seems to be somewhat unstable when reading
an image off of the drive on the 20276. (At least in RAID mode...
haven't gotten around to testing ATA133 stability)

ATA133 mode has the same problems. I think it's an issue with linux
and the PDC20276 chip.


-WD