Re: music can't play smoothly with xmms
Thus spake jqdkf@zju.edu.cn (jqdkf@zju.edu.cn):
> Hi,
>
> When there is a file transfer with the speed of more than 400k/s on my
> machine, like ftp download or upload, the music I play with xmms will
> flicker irregularly. My system is woody 3.0r1 with P4 2.4G, 512M DDR,
> ASUS P4PE, and I use alsa driver for my integrated sound card.
>
> What may be the problem? How can I solve it?
Check to see whether DMA is enabled on your hard disk. I'd always
imagined it would be by default - my mistake - until the other evening
when I was (for the first time) playing a DVD on my system. The video
was jerky and I discovered (via hdparm) that DMA was off for
/dev/hdc. Turned it on and - voila! - smooth video.
Out of interest, I checked my hard disks and found that it was not
enabled for them either. So, I did an experiment. Copied a ~130MB
audio file from one partition to another. Then turned out DMA for the
drive, deleted the target file, sync'ed (to flush disk buffers) and
ran it again.
The comparisons (from time) are illuminating:
without DMA:
real: 0m30.612s
user: 0m0.00s
system: 0m8.600s
with DMA:
real: 0m3.379s
user: 0m0.00s
system: 0m1.170s
an elapsed time improvement of 9-fold and a system overhead
improvement of 7-fold.
--
|Deryk Barker, Computer Science Dept. | Music does not have to be understood|
|Camosun College, Victoria, BC, Canada| It has to be listened to. |
|email: dbarker@camosun.bc.ca | |
|phone: +1 250 370 4452 | Hermann Scherchen. |
Reply to: