I have a PC which is 3 months old.The CPU usage shoots up sometimes to 60%
when almost no processes are running.I downloaded the Process Explorer and
found the usage by Hardware Interrupts is very high,about 90% of total usage.
I checked the IDE channels under Device Manager and they are DMA,not
PIO.What could be the possible reason?
In the event log,it's event No.9-atapi which occurs at the same time as the
shoot up of CPU usage.Can anyone help?I am under severe mental stress due to
this as my system becomes very slow
If IDE drives are slow to respond x number of times (I think the number is
3), XP will gear down from UDMA to PIO. The only way that I know of to
re-enable UDMA is to delete the controllers from Device Manager and reboot.
Device Manager may require you to remove the drives first, then the
controllers.
If your system has a master entry for the IDE channels (some chipsets add
this as an additional item or use it instead of individual listings), you
may or may not need to delete that too. If it's the only entry, delete it.
If it's an extra : Check its settings first. If you can select UDMA, do so.
Delete IDE channels only and restart. If no change, delete the IDE channels
and the master entry. Then restart. (You shouldn't have to but may need to
reinstall the chipset drivers after the reboot.)
NOTE: PIO mode is acceptable for supporting slower devices such as some
older cd/dvd readers and writers or older hard drives. Some newer systems
can run a fast device and a slow device on the same channel. But some will
do better with them separated - fast on one controller, slow on the other.
If successful, be aware that PIO mode may return. You may want to check
BIOS settings. If it's an available option, allow a few extra seconds for
the drives to spin up. Hopefully those few extra seconds will make sure
that they are always "ready" when XP finally sees them - keeping a return
of PIO mode at bay.
Also check that correct cables are being used and their connection is snug.
Example: 80 wire instead of 40 wire.
One more thing that could be looked at - standby or hibernate settings. If
this is a desktop and the drives are slow to return from a rest state,
consider disabling standby and hibernate. If this applies, keep an eye out
for a BIOS update from the system manufacturer that addresses power
management. Then decide if you want to give it a try to see if the issue
has cleared up enough that standby and hibernate can be used again on this
system.
If this is a laptop, contact tech support immediately to get this resolved.
In my opinion these features should be rock solid on a mobile system.
