[mythtv-users] X2 5000 enough to play HD?
Michael T. Dean
mtdean at thirdcontact.com
Wed Aug 27 18:36:22 UTC 2008
On 08/27/2008 01:24 PM, kanetse wrote:
> I have recently built myself a new MythTV system, which will
> eventually become a master backend/frontend. However, for now, I'm
> testing it in frontend only mode. I seem to be unable to play HD on
> it without either stuttering or severe audio-sync issues.
> The system is a:
> AMD Athlon 64 X2 5000
> Gigabyte GA-MA78GM-S2H (AMD 780G)
> 2 GB RAM
> CentOS 5.2
> MythTV-0.21 (from ATrpms)
> I was originally running it with ATI's proprietary drivers (Catalyst
> 8.8); however, there were other issues with, which I attribute to the
> quality of the driver itself. Recently, I popped in a nVidia GeForce
> 6600 (PCI-E), and set up XvMC.
> XvMC is, by all accounts, working properly (for example, I see a B&W
> OSD). However, HD playback is very poor. If closed captions are on,
> the audio stutters and movement is not smooth. Skipping ahead or back
> (using the arrow keys) causes audio to get severely out of sync with
> the video. All the while, CPU utilization is around 50% on one of the
> cores only; the other is nearly idle. SD seems to play fine.
> Could it be an issue of streaming the HD streams over the network?
> Maybe the master backend can't supply data fast enough?
> There don't appear to be any error messages in the mythfrontend.log,
> except a lot of NVP: Prebuffering pause message.
> My config should be able to handle HDTV even without XvMC, right?
Your timing is impeccable.
Assuming you're talking about MPEG-2-based HDTV (i.e. like in the US),
your processor will work without any issues for HDTV decoding. I had a
frontend with an AMD X2 4800+ (with 2GB RAM on an Asus A8N-E (with
NVIDIA chipset), using the integrated sound card (an ALC662, IIRC) and
the integrated LAN (a forcedeth GigE NIC)). It played HDTV perfectly,
and I could go up to 1.5x without stuttering.
However, I've been maintaining a Myth system for a friend (with software
that's identical to mine), and I've been trying to convince them to
switch to HDTV. I finally got them interested enough to switch,
and--since I had been wanting an upgrade so I could get better than 1.5x
timestretch--I donated my mobo/CPU/RAM to them and replaced them.
When I set up the system at their house (by taking an image of my
frontend and putting it on their HDD), we were able to get 2x
timestretch without issue... :) I'm pretty sure it's due to LAN
configuration and I/O issues.
Then, to make matters even stranger, I found the exact same issues
you're having with my new setup (and without modifying /any/ of the
software on the system).
My new setup started with an AMD Athlon X2 6000+, 2GB RAM, a Biostar
A740G M2+ (with AMD chipset). The state of the audio drivers for the
integrated sound (intel-hda) left something to be desired, so I tried a
MadDog ICE724 and a SoundBlaster Live! Value--neither of which helped.
The integrated NIC (a Realtek 100Mb using the r8169 driver) seemed very
slow, so I tried a PCI 100Mb one (forgot which driver) and a PCIe Gig-E
one (using via-velocity). Neither helped.
So, I thought, perhaps I just need a nicer mobo. I got an Asus M3A
(with AMD chipset) and swapped out the hardware. This one also uses the
intel-hda audio drivers, but has an integrated Gig-E NIC (using atl1
driver). Again, I tried the SB Live! Value and the ICE1724 and the 2
other NIC's without effect
What I've noticed on /both/ systems was that NIC performance drops to
unacceptable levels (about 4MB/sec between my frontend and
backends--where both backends have 100Mb NIC's) after transferring
several tens of gigabytes of data (around 50GiB received--generally,
while I've been testing it, within one day).
The big overlap on the two motherboards (and the big disconnect from the
previous) is the AMD chipset (versus the NVIDIA nForce on the previous
mobo). The AMD chipset is only /very/ recently supported (sometime
after 2.6.21), so I'm starting to think that the chipset support is
still too immature for the kind of work a Myth HDTV frontend needs to
do. I'm considering getting another mobo with an NVIDIA chipset. (The
really annoying thing is each time I do, I have to get another AM2+
processor and some RAM so I don't waste the other mobo--which seem to
work more than well enough for a "normal" non-Myth computer. Oh well,
the Biostar has become my new Myth dev box and was >>4x faster at
compiling Myth than my old Athlon XP 1700+ dev box. :)
I'll let you know once I figure it out.
In all the above configurations, I'm using Linux kernel 220.127.116.11 and
Moral of the story, don't mess with a working Myth system... :)
What chipset are you using?
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