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LTR-48125w sudden increase in CPU usage

PostPosted: Sun Aug 17, 2003 1:33 pm
by Dmayner
Greetings All,

I was wondering if any of you could explain why my LTR-48125w (most recent firmware) drive (CDRW) would suddenly start using more cpu? Also when I do a burn the leadin and leadout time has greatly increased. I am using XP Pro Sp1 and yes the drive is set to DMA. Windows reports that it is using UDMA 2. I have this drive as a slave to my Asus 52x. This drive is OK. The CD I used to test with was made by the drive using CDSpeed data test.

The rest of my system include:

K7T Turbo2 v5
VIA Chipset - most recent drivers installed
True power 330
Matrox g450
512 pc133

Here is what CDSpeed reports:

Seek Times

Random 1873 ms
1/3 2011 ms
Full 2728 ms

CPU Usage

1X 36 %
2X 28 %
4X 63 %
8X 100 %

Thanks for your help

Dave

PostPosted: Sun Aug 17, 2003 3:42 pm
by CDRecorder
Did you make any changes to your system recently?

Have you checked to make sure that all optical drives and hard drives in your system are using UDMA?

Also, you might want to try using the Microsoft drivers for your IDE controllers.

I hope this helps! :D

PostPosted: Sun Aug 17, 2003 4:13 pm
by Dmayner
CDRecoder,

Thanks for the reply. No I have not made any changes to my system. I recently did a clean install of XP Pro Sp1. I am using Microsoft drivers and they are set to UDMA. Any other sugesstions would be appreciated. Is this characteristic of a drive going bad? Again thanks for oyur help.

Dave

PostPosted: Sun Aug 17, 2003 4:18 pm
by UALOneKPlus
Back to basics - unplug your optical drives, start windows XP and play.

Then shut down, reinstall the Optical drives, and try again.

If that doesn't work, give the PC a kick!

Seriously, Microsoft's got some 'xp'lainin' to do!! :evil:

PostPosted: Sun Aug 17, 2003 5:56 pm
by Inertia
WinXP has a bug which they consider a feature. See DMA Mode for ATA/ATAPI Devices in Windows XP. If more than six DMA errors are received, WinXP will turn off DMA and revert to PIO mode 4. High speed transfers using PIO 4 are very inefficient and have very high CPU utilization due to the lack of DMA (Direct Memory Access).

The symptom you have described is consistent with this WinXP "feature". You may have originally checked the settings and confirmed that DMA was enabled, only to find later that it has been reset to PIO mode without user intervention.

This is the most likely cause of your problem. If this is the case, the usual temporary fix is to uninstall the ATAPI device from Device Manager and reboot. When the burner is redetected, usually DMA will be reenabled.

If Device Manager continues to show DMA as enabled, the high CPU utilization indicates that something is probably interfering with the proper implementation of DMA and it is still not working. In this case I would double check the system BIOS for the proper DMA settings. Auto-detect is usually preferable, but if the problem continues with this setting try changing to a forced UDMA setting if available.

If UDMA worked OK before the most recent VIA drivers were installed, try an earlier version of the drivers.

PostPosted: Sun Aug 17, 2003 10:02 pm
by Inertia
There is an interesting and plausible explanation of the WinXP DMA bug in the last post by AngelDeath in the thread at http://forum.cdfreaks.com/showthread.ph ... adid=60218

PostPosted: Sun Aug 17, 2003 10:33 pm
by dodecahedron
Inertia wrote:There is an interesting and plausible explanation of the WinXP DMA bug in the last post by AngelDeath in the thread at http://forum.cdfreaks.com/showthread.ph ... adid=60218

thanks for that, Inertia!
now all we have to do is wait for SP2 hum! :o

PostPosted: Mon Aug 18, 2003 8:29 am
by Dmayner
Thanks everyone,

This has been a very good thread. I learned a lot. I did delete the drive and have XP reinstall it. It did seem to work. I think I will try to wait for SP2 before messing with the registry. Thanks again for all the help.

Dave