Author Topic: "Interrupts" - killing my CPU! (Read 22299 times)

nosh · « **on:** February 16, 2008, 08:56 AM »

My system really choked today while copying a few large files from a DVD on my machine to another PC on the network.
Process Explorer showed "Interrupts" lingering between 30 and 45(!)% CPU. I disabled the firewall which was eating another 20% but the PC still somewhat stuttered. Once the copying finished it immediately reached its normal idle state ~80% free. I realise hardware interrupts are integral to hardware access but is there some way to alleviate the situation? Perhaps a BIOS/firmware/system setting that could be tweaked? Maybe better quality media?

I've never had the PC slow down this bad under similar circumstances in the past.

f0dder · « **Reply #1 on:** February 16, 2008, 10:33 AM »

Check device manager and see if any of you IDE ATA/ATAPI controllers are set to PIO mode rather than DMA - my guess is that they are, and this query will help you

Carol Haynes · « **Reply #2 on:** February 16, 2008, 10:42 AM »

80% idle is normal ??? Is that 20% for your Firewall - if so what the heck are you using?

Darwin · « **Reply #3 on:** February 16, 2008, 11:04 AM »

Good piece of advice on the PIO/DMA check. I *just* fixed this problem on my wife's laptop after months of beating my head against a wall and two days after doubling the RAM (my 5 year then dumped it on the floor and broke both the monitor and the power connection...). This made a machine that was almost unusable a SPEED DEMON. Stupidly, I used to have this problem with an old notebook and should have thought to check it long ago...

Darwin · « **Reply #4 on:** February 16, 2008, 11:06 AM »

PS This is the tip page that finally allowed me to fix my wife's notebook (it was refusing to change to DMA prior to working through the advice on this page): http://winhlp.com/node/10 - first hit on f0dder's search

f0dder · « **Reply #5 on:** February 16, 2008, 11:14 AM »

Btw iirc it's not necessary to reboot, I'm pretty sure I found a workaround where you can just disable+reenable the controller, and new DMA settings would be applied... but reboot is the safe way

nosh · « **Reply #6 on:** February 16, 2008, 11:15 AM »

Bang on the money, f0dder! Thanks. I had a optical media recovery software that would do this every time so I did know about the PIO issue killing burn speeds but I never would have guessed it could cause interrupt spikes too. This probably happened coz a friend got a DVD-RW to my place a couple of days back that kept coastering for some reason, I generally just stick to DVD+R. Why can't these momos atleast warn me when they do this?

Carol, the firewall was off but yeah 70-80% idle is not that unusual if I'm in hands-off mode.

I try and stay away from any kind of realtime scanners or (content) indexing programs as far as possible. It's not always like that of course - I run Firefox, after all.

f0dder · « **Reply #7 on:** February 16, 2008, 11:23 AM »

80% idle when not doing anything? That's 20% CPU usage

With Process Explorer running (spends a little cpu time on every update), firefox idling in the background, PuTTY connected to my server and showing rTorrent (which updates a couple of times per second?), and some other apps (sitting idle), I generally sit between 0 and 1.15% CPU usage. 20% CPU usage on idle sounds very very wrong.

wreckedcarzz · « **Reply #8 on:** February 16, 2008, 11:26 AM »

I hit 7-20% CPU usage idle, and all programs are sitting in my tray except Firefox, Windows Task Manager, Pidgin and Xfire. I don't see how you can get such a low CPU usage, f0dder

f0dder · « **Reply #9 on:** February 16, 2008, 11:35 AM »

Well, I do have a quadcore CPU now, but back on my dualcore it was max ~3.5% CPU or so.

nosh · « **Reply #10 on:** February 16, 2008, 11:51 AM »

Thanks for the link Darwin, the method I knew to work was - Delete Device -> Reboot - and it didn't fail me this time either.

f0dder, between the startup folder, HKCR/Run & HKLM/Run I have 42 items enabled (just counted) and I have a P4 3GHz so I can't exactly afford to complain.

I do have a "Minimal" startup profile that I use for gaming, I'm sure the results are somewhat better then.

Deozaan · « **Reply #11 on:** February 16, 2008, 01:08 PM »

Right now I have 3 Windows Explorers, WhatPulse, Internet Explorer, Firefox (with 7 tabs open), Hamachi, Google Talk, uTorrent, WinAmp, Microsoft Groove, FileHamster, Active Desktop Calendar, PowerISO, UltraMon, and Symantec AntiVirus running or in the tray. With a total of 55 Processes running.

My System Idle Process is usually at 98 or 99% with an occasional dip down to the mid 80s for about a second.

I don't know how it's possible to get 20% CPU usage when you're not touching anything.

EDIT: My CPU is a single core AMD 64 3500+ 2.2Ghz running on WinXP SP2 (32-bit)

nosh · « **Reply #12 on:** February 16, 2008, 01:27 PM »

Well, CPU strength would be an obvious contributing factor.
I notice that if I let the PC just sit for a minute without touching anything it does go better than 80%. Sygate seems to be the consistent offender here, it's on its way out shortly anyway.

Disclaimer: Haven't disabled anything for the screenshot.

Carol Haynes · « **Reply #13 on:** February 16, 2008, 01:55 PM »

That's very strange - I used to use Sygate on my old Athlon XP 1600 and it used to idle at < 1% (usually registering 0%).

Something is screwed up if Sygate ever even spikes at 20% CPU !

nosh · « **Reply #14 on:** February 16, 2008, 02:11 PM »

The 20% spikes were partly because of the network transfer, Comodo seems to like uTorrent much better so it'll be substituting Sygate for good shortly.

J-Mac · « **Reply #15 on:** February 17, 2008, 12:59 AM »

I used to be at around 98% most of the time my PC was idle, but now that I use DOpus I haven't seen that for a while. DOpus seems to constantly be at around 4 - 5%.

Jim

f0dder · « **Reply #16 on:** February 17, 2008, 06:39 AM »

The 20% spikes were partly because of the network transfer, Comodo seems to like uTorrent much better so it'll be substituting Sygate for good shortly.
-nosh (February 16, 2008, 02:11 PM)

Well, if you're leeching with µtorrent, your system isn't setting idle - especially not if you're downloading at high rates

. 20% CPU usage still does sound like a lot, but torrent downloading means a lot TCP connections...

nosh · « **Reply #17 on:** February 17, 2008, 08:32 AM »

Not exactly on high speed broadband but yeah, quite a few TCP connections established at the moment.

J-Mac, DOpus is notorious when it comes to resource consumption but it actually does seem to put what it takes out of your system to good use. I'm not a DOpus regular but I remember its GUI being more fluid than most of the competition from when I tried it, especially when it came to stuff like browsing heavily populated folders in thumbnail mode. It's probably doing a lot of internal cacheing to stay a step ahead of the user.

Lashiec · « **Reply #18 on:** February 17, 2008, 01:29 PM »

I hit 7-20% CPU usage idle, and all programs are sitting in my tray except Firefox, Windows Task Manager, Pidgin and Xfire. I don't see how you can get such a low CPU usage, f0dder
-wreckedcarzz (February 16, 2008, 11:26 AM)

Heh, that's the CPU usage I got on my old PIII

BTW, µTorrent does not get along with almost every security app out there, so nosh figures are normal, I suppose.

cmpm · « **Reply #19 on:** February 17, 2008, 04:10 PM »

3-10% here, usually around 5%
2 p3's running 40 or so process' each,
including firefox idling in the tray

got rid of some auto updaters
google, apple, real, java....
manually update those occasionally
took out itunes, don't use it anyway

Darwin · « **Reply #20 on:** February 17, 2008, 04:52 PM »

Thanks for the link Darwin, the method I knew to work was - Delete Device -> Reboot - and it didn't fail me this time either.
-nosh (February 16, 2008, 11:51 AM)

No worries! Actually, I've just realised in re-reading the thread that you were concerned about your optical drive and not a harddrive, which is what I was referring to...

Darwin · « **Reply #21 on:** February 17, 2008, 05:03 PM »

All right, then, I'll come clean: at idle my P-M 1.4Ghz single core anachronism chugs along at anything between 20 and 100% CPU utilization... Often it's a cocktail of BitDefender (via an svchost.exe process), Notezilla, and IndieVolume that "do it". I should probably take a look at all this, but I live with it because the computer remains fully "useable" and it's old. Very old.

nosh · « **Reply #22 on:** February 17, 2008, 05:05 PM »

Shite! Where were you yesterday when I took so much heat?

Grorgy · « **Reply #23 on:** February 17, 2008, 10:02 PM »

my laptop with a 1.5 celeron m sits around 2 to 6 % with occasional spikes around 20 -25%, with 44 processes currently running, including outlook 2003 notezilla eset security suite, firefox and so on. I get nervous if its working hard doing nothing, seems to me its not doing what it should be, any piece of software that has to run all the time had better do not much when its not doing its job or its life on the virtual grorgy world is short. I have enough trouble with things i need but dont need to run all the time taking all my processor.

Darwin · « **Reply #24 on:** February 17, 2008, 11:04 PM »

Oh yeah... at idle, but with Outlook minimized to the tray, my notebook has 69 processes running. Don't worry, folks, I've seen the light and have already uninstalled 20 apps this afternoon and am still plugging away ("only" 337 installed at the moment...) at it. Next up is a re-evaluation of what runs on system start - the little Bluetooth app that hogs about 50 MB of RAM continuously is looking attractive for the axe - I only use it to grab pictures off my phone!