Hello,

I have problems with dvd playback performance on my laptop: movies freeze
every 2 seconds for about half a second. I have read that other people
having the same problem, got their troubles solved by enabling dma, but
unfortunately this does not seem to fix anything in my case.
I must say that I have also a windows partition on my laptop and movies are
smooth on that partition.
I have an ATAPI 24X DVD-ROM CD-R/RW drive, 2048kB Cache, DMA.
When I run
> hdparm -tT /dev/hdc

I get the following:

/dev/hdc:
Timing buffer-cache reads: 408 MB in 2.01 seconds = 203.32 MB/sec
Timing buffered disk reads: 6 MB in 3.12 seconds = 1.93 MB/sec

It seems to mee that 1.93 MB/sec are too slow. Can anybody suggest me what
to do?

--giadem

google is your friend
http://www.linuxdevcenter.com/pub/a/...29/hdparm.html

Thanks for replying!
...Well, I've tried all that staff already, but no success.
The output of
hdparm /dev/hdc

is the following:

/dev/hdc:
HDIO_GET_MULTCOUNT failed: Invalid argument
IO_support = 3 (32-bit w/sync)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 1 (on)
readahead = 256 (on)
HDIO_GETGEO failed: Invalid argument

It is strange that I do not have such a problem under windows on the
same machine. There should be something to speed up the execution
that I don't know.

Any help is very much appreciated!

--giadem

In your /etc/hdparm.conf near the bottom of the file is an example for the first cdrom0 uncomment it and use /etc/init.d/hdparm restart and see if this helps. If it does not work then try this after commenting out the previous suggestion.

According to your output above it should already be working but trying these should not hurt and can only help.

Thanks a lot Stephen,

I've implemented your suggestions but unfortunately I did
not notice any improvement.
One more thing that I've experimented is the following:
if I reduce the movie window to about 320x240 then
the problem disappear: the playback becomes really fluid;
as soon as I switch back to fullscreen mode, it becomes to
freeze again.
Moreover, I noticed that there is almost no difference in performance between dma enabled and not. Namely, here are the two respective outputs of 'hdparm -tT /dev/hdc'

dma enabled:

/dev/hdc:
Timing buffer-cache reads: 392 MB in 2.01 seconds = 195.25 MB/sec
Timing buffered disk reads: 6 MB in 3.12 seconds = 1.93 MB/sec

dma not enabled:

/dev/hdc:
Timing buffer-cache reads: 396 MB in 2.00 seconds = 197.93 MB/sec
Timing buffered disk reads: 6 MB in 3.87 seconds = 1.55 MB/sec

I repeat that I have no problem under windows on the same machine
and with the same dvd. So it cannot depend on my laptop.
That is very frustrating. But I don't want to give up. Please help!

--giadem

its not dma or your dvdreader it has to do with your video driver thats why its ok at 320x240 ..you may need to load the proper driver from the manuf rather than the generic xfree or x.org

You may want to check and make sure that the DMA is getting turned on when you boot for the drive and for the chipset on the motherboard.

Otherwise I'm agreeing with wrat here what driver are you using for the video?

The output of dmesg is the following:

DMA zone: 4096 pages, LIFO batch:1
VP_IDE: VIA vt82c686b (rev 42) IDE UDMA100 controller on pci0000:00:07.1
ide0: BM-DMA at 0x1840-0x1847, BIOS settings: hdaMA, hdbio
ide1: BM-DMA at 0x1848-0x184f, BIOS settings: hdcMA, hddio
hda: 78140160 sectors (40007 MB) w/2048KiB Cache, CHS=65535/16/63, UDMA(100)
hdc: ATAPI 24X DVD-ROM CD-R/RW drive, 2048kB Cache, DMA

So I think DMA is working.
Anyway, I've installed kaffeine (before I've been using okle) and now the playback is
improved a lot, although not as smooth as under windows.
The best performance is reached when using the 'very low cpu usage' option.

Concerning my video card, I have a ProSavage VIA Twister-K/KT133x/KM133 chipset.
I use the xfree86 x server and I've the 'savage' driver installed.
I don't know if this is the best setting for my video card...

Thanks a lot to HappyTux and wrat for helping me!!

for the best video performance got to the manuf web sie get their driver and install it with the instructions