[mythtv-users] CPU performance governor vs disabling AMD Cool n Quiet

[Michael PARKER]

> -----Original Message-----
> From: mythtv-users-bounces at mythtv.org [mailto:mythtv-users-bounces at mythtv.org] On Behalf Of
> faginbagin
> Sent: 23 October 2010 19:49
> To: mythtv-users at mythtv.org
> Subject: [mythtv-users] CPU performance governor vs disabling AMD Cool n Quiet
> 
> First some background to my questions, and to hopefully help anyone who
> encounters the same problem:
> 
> I "upgraded" my sister's mythtv box, replacing an older ECS mobo/AMD
> Sempron 32 bit single core CPU with an ASUS M3N78 PRO mobo/AMD Athlon X2
> 4850e dual core cpu. The "new" computer used to be my mbe/fe and had
> worked fine with two HVR-1600 cards. But with her PVR-150 and a HD-5500,
> she's been having trouble with the PVR-150 choking after a few days of
> recording. I think the problem was due to me enabling AMD Cool n Quiet
> in the BIOS (it was disabled by default). She's been sensitive to fan
> noise, so although it wasn't enabled when the computer was mine, I
> thought I would enable it for her.
> 
> The problem manifested itself with an incomplete recording after 2-7
> days of uptime, followed by completely failed recording attempts plus
> dmesg output filled with messages like:
> ivtv0: DMA TIMEOUT 00000001 0
> 
> Turning on debug output in the ivtv driver showed these two messages of
> interest at the time recording began to fail:
> ivtv0:  warn: DMA ERROR 00000003 00000000 00000013 0
> ivtv0:  warn: DMA ERROR 00000003 00000000 00000011 2
> 
> The only way to get the PVR-150 to work was to reboot. Stopping the
> mythbackend, unloading/reloading ivtv and restarting mythbackend didn't
> clear the problem.
> 
> I think I have solved the problem by changing the CPU frequency governor
> from ondemand to performance. It's only bee a week, so I'm going to give
> it another week, and if I get no more failed recordings, I will declare
> success and make the change permanent. My questions are:
> 
> Should I change the BIOS setting to disable AMD Cool n Quiet or do
> something to make the CPU frequency governor = performance at boot time?
> 
> Is there a difference, any advantage using one method over the other,
> any gotchas?
> 
> Also, has anyone seen a difference in the performance of the M3N78's IGP
> (nVidia 8300) with these various tweaks?
> 
> I ask because the performance of the IGP has been disappointment with
> Cool n Quiet enabled and the ondemand governor. I never used the IGP
> since I've still got an SD TV. The IGP is barely able to play 1080i
> content with the VDPAU slim profile. Such content is unwatchable with
> VDPAU normal. I'll get a chance to see if it's any better with the
> performance governor tomorrow. If not, it looks like I'll have to get
> her a GT 220 GPU.
> 
> TIA,
> Helen
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Helen,

How much main memory are you allocating to the IGP? 

I'm running a M3N78-EM mobo and noticed that a recent BIOS update permitted up to 512MB to be allocated (vs. the 256MB permitted by the as-shipped BIOS). My M3N78-EM is running with 4GB of DDR2-1066, an AthlonII X4 605e, and Cool n'Quiet enabled. 

1080p playback with VDPAU appears to work without problems - the only graphical issues I'm aware of relate to the x64 Beta Flash plug-in apparently being unable to display some Flash content fullscreen (horizontal flashing/breakup).

Mike