[mythtv-users] Re: Nova-T ac-tex damaged etc.

[Scammell, David]

Martin,

I'm seeing this, the errors appear to kill the backend as well.

I've got a UDMA 133 drive (MAXTOR 7Y250P0), running at UDMA 100, UDMA
support is compiled in (sis5513-sis735) and (appears) is auto activated by
the kernel. Unmasking interrupts didn't really make any difference to the
transfer rate, ~10MB/s.

I suspect this motherboard supports UDMA 133 transfers but this kernel,
vanilla 2.4.22 inc dvb support doesn't grok it. I think I will have to look
for a bios upgrade, then possibly tweak the sis driver to understand it.
Name of the motherboard is not to hand though right now.

Should I see <much> better throughput than this? 

I'm surprised that the UDMA configuration of the machine causes so such an
issue, the bandwidth needed to disk from the nova-T shouldn't be so much,
even with a slightly mis-configured disk. I'll have to try dvbsteam again,
it did stream data perfectly to disk before, no significant errors. Why
should it have such a problem when Mythtv is in charge?

I think getting the correct channel info of Freeview from xmltv will be the
next challenge!

David Scammell
Unix System Administrator
Global Tech. OPS (Chichester)
Mercer HRC - Extension 22525
+44 (0)1243 522525 Desk
+44 (0)7789 030182 Mobile



-----Original Message-----
From: Martin Brown [mailto:Martin.Brown at macquarie.com] 
Sent: 16 December 2003 21:31
To: mythtv-users at mythtv.org
Subject: [mythtv-users] Re: Nova-T ac-tex damaged etc.


Just to let people know who might have the same problem that I had: large
scale quantisation break 
up, streaming "ac-tex damage" errors, etc.:

Check that DMA is enabled on the disk storing the Myth data. I had to
recompile my kernel with 
support for my IDE controller before I could do this, but then turning DMA
on with hdparm boosed the 
disk speed 10 fold and got rid of the errors I was seeing.

Thanks to those who responded to my quenstions.

Now on to the next challenge...

Martin Brown


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