Re: High CPU Usage on software raid 0

Look, if this was a virus, I'd say it's showing pretty peculiar
symptoms. I'd be very suprised if you've ever heard of a virus that
describes what I've explained. Only stopping one hard drive from
performing at its regular level.

Thankyou for making me look into the problem further. I've made some
interesting discoveries.

Normally I've got Seti@home running in the background, which makes my
CPU usage at 100% all the time on the Performance tab. Not that all the
CPU is going to seti@home. Looking at the kernel times (the red graph
in the performance tab), it doesn't really do much.

When I close Seti@home everything pretty much goes dead and before
doing any reading or writing on the raid 0, my system is running with
the following processes using 0-2% usage.

Opera.exe
Explorer.exe
javaw.exe (Azureus.exe)

Copying large files between the other hard drives on my computer make
explorer.exe work anywhere from 5-10% of my CPU. Noting here that the
kernel cpu usage can go anywhere between that 5 and 10% depending on
what seems to be random to me.

However when I copy files to or from (do any read or write access) on
my raid 0, one thing always occurs, my CPU & Kernel usage hit the roof,
going to around 80% but can go to 100 or 60.

Then either one of two things occur with the processes using my system.

1. My System Idle reports using most of the CPU anywhere from 50-95%
and the other processes look normal, or

2. All other processes are now using a lot more, and all in equal
amounts.

So where before it would be
Opera 1
Explorer 2
javaw 1

now it's

opera 17
explorer 34
javaw 17

or

opera 50
javaw 25
explorer 12
winamp 12

It seems to be as if the 50 or 25, are actually the 1 and 2 but
multiplied by 25 (or 17 or some arbitrary number)

Those processes are certainly not doing that much work, I've never seen
opera use 50% of my CPU when it's idle.

One thing is very clear though, in the performance graph, the red
kernel graph is always matching my green graph. Normally teh kernel
graph is 0 to 10 under all regular operations, but to see it match the
green graph says to me that the kernel is using up everything.. and
leaving little else for all teh other processes.

I'm making stabs in the dark here when I say that it says to me that
why the other processes show that they are using 50, 25, 12, 17 percent
of the CPU is because that, they are using 50% of what is actually left
after the kernel has been using it all.

I'm going to try doing some of these tests in safe mode and see if it
does the same things

.

Relevant Pages

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