Direct Memory Access DMA

Ohne DMA muss die CPU die Speicehrblöcke zwischen den Geräten hin- und herschaufeln. Mit DMA können das machen Geräte direkt tun. Besonders bei Laufwerken und Grafikkarten wirkt sich das erheblich in der Geschwindigkeit aus.

For „ruckelfreie“ DVD: hdparm /dev/hdc (when DVD is hdc) 32-bit access and DMA should be on (1)

else try to turn it on:

hdparm -c 1 /dev/hdc (32bit)
hdparm -d 1 /dev/hdc (dma)

see configuration of dma etc. /eg. harddisc): cat /proc/ide/hda/settings

By the way, if you want to review the boot messages, run „dmesg“ just after booting up.

It's probably that the kernel is disabling DMA transfers, because they often don't work right on many IDE controllers. You can try reenabling it by installing „hdparm“ and running „hdparm -d 1 /dev/hda“. If you want to test the speeds that you're getting, run „hdparm -T -t /dev/hda“ before and after the change.

To make it permanent you'll have to put the hdparm command in your startup scripts

/etc/rc.d/rc.local
 
Nach oben
dma.txt · Zuletzt geändert: 2024/02/29 13:36 von 127.0.0.1
chimeric.de = chi`s home Creative Commons License Valid CSS Driven by DokuWiki do yourself a favour and use a real browser - get firefox!! Recent changes RSS feed Valid XHTML 1.0
DFmW2CEce3htPL1uNQuHUVu4Tk6WXigFQp   Dogecoin Donations Accepted Here    DFmW2CEce3htPL1uNQuHUVu4Tk6WXigFQp  DFmW2CEce3htPL1uNQuHUVu4Tk6WXigFQp