_________________
Retired KM user (R4 - R6.04); friend to LH users.

on Asus A7A266 mobo with Athlon 1.33Ghz, Maxtor 80Gb
206MB/sec and 40.51 MB/sec

on Tyan Trinity371 BX mobo with P3-600EB 133FSB, Maxtor 40Gb
203MB/sec and 29MB/sec

I would say DMA is enabled

This is a Seagate 160 gig disc on an Asus A7N8X-VM board.

$ hdparm -c1 -m16 /dev/hda

/dev/hda:
multcount = 16 (on)
IO_support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 19457/255/63, sectors = 312581808, start = 0



/dev/hda:
Timing buffer-cache reads: 128 MB in 0.35 seconds =365.71 MB/sec
Timing buffered disk reads: 64 MB in 1.63 seconds = 39.26 MB/sec

EDIT - Fri May 27, 2005 6:57 pm
On my new WD Caviar SE 320 gig:

/dev/hda:
Timing cached reads: 1360 MB in 2.00 seconds = 679.08 MB/sec
Timing buffered disk reads: 182 MB in 3.03 seconds = 60.15 MB/sec


EDIT - Mon July 14, 2008 7:13 pm
On my new WD Caviar SE 500 gig:

/dev/hda:
Timing cached reads: 734 MB in 2.00 seconds = 366.46 MB/sec
Timing buffered disk reads: 190 MB in 3.01 seconds = 63.16 MB/sec

EDIT - Sat Oct 11, 2008 9:51 am
One my old old WDC WD800JB-00CRA1 80 gig:

/dev/hda:
Timing cached reads: 1142 MB in 2.00 seconds = 570.72 MB/sec
Timing buffered disk reads: 140 MB in 3.01 seconds = 46.48 MB/sec


EDIT - Sun Oct 12, 2008 5:30 am
My old Hitachi Deskstar HDS722516VLSA80 (SATA1)

/dev/sda:
Timing cached reads: 1120 MB in 2.00 seconds = 559.78 MB/sec
Timing buffered disk reads: 176 MB in 3.01 seconds = 58.42 MB/sec

EDIT - Sat Jan 3, 2009 2:41 pm
Relatively new Gen 11 Seagate (SATAII): ST3750330AS under Ubuntu 8.10

/dev/sda:
Timing cached reads: 15880 MB in 2.00 seconds = 7952.77 MB/sec
Timing buffered disk reads: 344 MB in 3.01 seconds = 114.19 MB/sec

EDIT - Tue Mar 24, 2009 3:54 pm
Relatively new Western Digital Caviar Black WD7501AALS (SATAII): ST3750330AS under Ubuntu 8.10

/dev/sda:
Timing cached reads: 13626 MB in 2.00 seconds = 6823.61 MB/sec
Timing buffered disk reads: 246 MB in 3.00 seconds = 81.88 MB/sec

_________________
Retired KM user (R4 - R6.04); friend to LH users.

graysky, you rule for posting that link. I just got a 200 gigger to throw into my myth box and have been having huge performance problems with it (can't access it for like 2 minutes at startup, horrid transfer rates once it decides to quit flaking out, etc.) I knew it just needed a little tuning but didn't have a good source of info.

Short story long, I can finally use the drive for more than one thing at once. My #s aren't as good as yours, but my mobo is old, so the pci bus is slow (I forget the speed).

Anyhow, thanks! My myth box is much happier now!

I get:
root@mythtv:~ # hdparm -c1 -m16 /dev/hda

/dev/hda:
setting 32-bit IO_support flag to 1
setting multcount to 16
multcount = 16 (on)
IO_support = 1 (32-bit)
root@mythtv:~ # hdparm -Tt /dev/hda

/dev/hda:
Timing buffer-cache reads: 128 MB in 0.15 seconds =853.33 MB/sec
Timing buffered disk reads: 64 MB in 1.09 seconds = 58.72 MB/sec

root@mythtv:/home/mythtv# hdparm -X66 -d1 -u1 -m16 -c3 /dev/hda

/dev/hda:
setting 32-bit IO_support flag to 3
setting multcount to 16
setting unmaskirq to 1 (on)
setting using_dma to 1 (on)
setting xfermode to 66 (UltraDMA mode2)
multcount = 16 (on)
IO_support = 3 (32-bit w/sync)
unmaskirq = 1 (on)
using_dma = 1 (on)
root@mythtv:/home/mythtv# hdparm -Tt /dev/hda

/dev/hda:
Timing buffer-cache reads: 128 MB in 0.96 seconds =133.33 MB/sec
Timing buffered disk reads: 64 MB in 2.64 seconds = 24.24 MB/sec

I have DMA enabled on my HD:

/dev/hda:
Timing buffer-cache reads: 128 MB in 0.47 seconds =272.34 MB/sec
Timing buffered disk reads: 64 MB in 2.01 seconds = 31.84 MB/sec

But, I don't believe it is enabled on my DVD drive, as DVD playback through Xine is very jerky. Running xine-test (of whatever it is, I'm at a windows box at present) showed that it couldn't tell, because it showed possibly an IDE drive running in SCSI mode? I can post exeact output if needed. How can I DMA for sure?

_________________
Where all think alike, no one thinks very much.
- Walter Lippmann

Perhaps reading the article...
hdparm -d1 /dev/hdX

_________________
cesman

When the source is open, the possibilities are endless!

well the thing is that the dvd/cdrom etc on knoppmyth is an ide device running in scsi mode, and is probably accessed at /dev/scd0 now I'm not sure if turning on dma on /dev/hdc (if it's the secondary master) would work or not. I've never had any trouble so I haven't had to look into this one.

Yes, it will work.

_________________
cesman

When the source is open, the possibilities are endless!

Yes, it works. I had to do it on my dvd drive.

Hi,

Use hdparm -i to to determine what the drive is capable of:

look for the highest "udmaX" where X is a number. For example, if X is a "6":

hdparm -c1 -k1 -u1 -d1 -m16 -a8 -Xudma6 /dev/hda

for a cdrom/dvd, drop the "-m16 -a8" as it doesn't understand it:

hdaparm -c1 -k1 -u1 -d1 -Xudma2 /dev/hdc

put this in the /etc/init.d/bootmisc.sh if you're running debian or a derivitive. For others, look for a harddisks in /etc/sysconfig.d or similar

_________________
Jason L. Froebe

HealthyPals (http://www.healthypals.com)
Bookcrossing (http://www.bookcrossing.com)
WebBlog http://www.livejournal.com/users/jfroebe

Hi,

One more thing.. if your system supports it, don't forget to add "idebus=66" to the append line of lilo (grub, etc)

for example:
append="idebus=66"

this will allow you to utilize the higher ultra ide speeds (i.e. 66, 100, 133). Please note that the "66" in the idebus line is for activating the 66MHz PCI bus (normally it is 33MHz).

Jason

_________________
Jason L. Froebe

HealthyPals (http://www.healthypals.com)
Bookcrossing (http://www.bookcrossing.com)
WebBlog http://www.livejournal.com/users/jfroebe

This is a very interesting thread! Thanks for posting that - just built a prototype KnoppMyth box Today just to test it (from an boggo E-machines Celery 1200 with 384Mb RAM) and after finally getting it to play DVD's (the libdvdcss issue - also solved by searching this board) I had a feeling that the drive wasn't delivering the data fast enough, as the video soon lagged behind the sound and stopped and started all the time.

Sure enough, after reading that article, and experimenting with the settings, it now works almost flawlessly (still some pauses but the hardware is fairly low powered).

Curiously, my numbers got worse on the hdparm test (on hda) after changing to 32bit DMA66 et al, but actual performance got better... hdparm did suggest that the test results (before applying the changes) were bogus though.

Got it playing DVDs, DIVX AVI's, mp3's over an NFS to my music server - I'm encouraged enough to build a proper box (in a spouse friendly case ) for this after Today - very impressive.

Like the article said - I assumed that the kernel modules and drivers probed for this sort of thing these days and optimised themselves for the hardware. I think this bears some further research and testing!

I am having a problem with my new Myth box.

1. Everytime I change the channel the video and sound skip some. Sometimes this continues, but can be fixed by pausing the video and waiting a few seconds
2. Both Live tv and recorded seem to have extremely low frame rates. The video is much more choppy than it should be

I don't think it is my system (see specs below) and the TV Tuner should have hardware encoding.


I think these problems are both related to the HDD. When I run the hdparm -Tt test I get a cached read in the 400's (MB/sec), but the timing buffered disk reads only gives me between 9 and 20 MB/sec.
The drive is extremely old and only supports ATA 33.

Could this be the problem?? I'd like to upgrade to get more space, but it won't be worth it if it's not going to give me a full 30 fps. Also, is it perhaps a setting in MythTV that I have missed?


My specs -
Athlon Sempron 2400+
512 MB DDR 333
20 GB ATA-33 HDD
Hauppauge PVR-150 (non MCE)

Machine Status:
Load: 1.30, 0.61, 0.23
RAM: 501MB, 396 MB used, 105 MB (20%) free
Swap: 490 MB, 0 used