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

[Jarod Wilson]

On Sat, Oct 23, 2010 at 7:49 PM, David Asher <asherml at gmail.com> wrote:
>
> On Oct 23, 2010, at 6:56 PM, Jarod Wilson wrote:
>
>> On Sat, Oct 23, 2010 at 5:44 PM, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
>>> On 24 October 2010 08:44, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
>>>> When AMD Coon n'Quiet is enabled, the default governor set the bus
>>>> speed too low to properly feed the nvidia card for VDPAU usage. As
>>>> such, VDPAU is unusable. Set the minimum frequency to be around
>>>> 1.8GHz.
>>>>
>>>
>>> Forgot to add that it wouldn't be any different with a GT220
>>
>> Interestingly enough though, my main frontend box is an athon 64 x2
>> (~2.7GHz, iirc) with a GT220. It runs with the ondemand cpufreq
>> governor enabled, with both cores pretty much always throttled back to
>> 1GHz, and it never has a single issue with vdpau playback...
>
> Doesn't that make sense if the GT220 has dedicated memory, but the integrated chipset is using shared main memory?
>
> Shared main memory would be subject to the processor scaling back the bus frequency, but dedicated memory would be clocked by the GT220 itself and not subject to the processor.

Well, memory speed isn't the only consideration, there's also system
bus speed, pcie bus speed, etc -- could be that video can't be fed to
the card fast enough due to some sort of system-level bus choking
(before even hitting graphics memory). Not sure what the supposed
bottleneck is. Whatever it is though, I'll just consider myself
fortunate to have a system that isn't affected. :)


-- 
Jarod Wilson
jarod at wilsonet.com