[vdr] Vdr or driver performance dropout

Steffen Barszus st_barszus at gmx.de
Sun Mar 11 19:25:40 CET 2007


Kartsa schrieb:

> Stefan Huelswitt kirjoitti:
>
>> On 01 Feb 2007 Reinhard Nissl <rnissl at gmx.de> wrote:
>>
>>  
>>
>>> Heikki Manninen wrote:
>>>
>>>    
>>>
>>>>> I've noticed that earlier when I was using PIII 550 MHz and vdr 
>>>>> 1.3.22 (or something about) I made a test by recording nine 
>>>>> channels simultaneously and watching a recording at the same time. 
>>>>> I remember there seemed to be no trouble doing it. Now when I have 
>>>>> vdr 1.4.4 after fourth recording starts vdr becomes sluggish and 
>>>>> there starts to come errors on log:
>>>>> dvb-ttpci: warning: timeout waiting in LoadBitmap
>>>>> when pushing menu button. And ofcourse no menu appears or menu 
>>>>> appears only partly.
>>>>>         
>>>>
>>>> Exactly the same thing here and with the latest and the second latest
>>>> firmware. My FF 2.1 TT card starts to die after third simultaneous
>>>> recording. But then again, I think that budget cards are much 
>>>> better in
>>>> this area.
>>>>       
>>>
>>> Most likely, it's me who has to be blamed. Around 1.3.27, 
>>> cVideoRepacker
>>> was introduced which has an impact on CPU load. This could be a reason
>>> why the menu is slow when running several recordings at the same time.
>>>     
>>
>>
>> I don't think that the problem is related to anything on VDR
>> side.
>>
>> AFAIK the bandwidth from ARM to PCI bus is very limited on
>> full-featured cards. With 3 recordings being transfered to VDR
>> there is simply not enough bandwidth left for the OSD transfers.
>> Hence the LoadBitmap timeout.
>>
>> I experience the problem since VDR introduced concurrent
>> recordings and I cannot believe that there is any VDR / firmware
>> combination which doesn't show this behaviour as it's IMO a
>> hardware limitation.
>>
>> Budget cards doesn't have this limitation, they can transfer the
>> full transponder without problems.
>>   
>
> I know the performance was better when I was using vdr-1.3.22. I know 
> I had 9 recordings going on and still I was able to watch a previous 
> recording and I was using a slower cpu and a ff card. Ofcourse my 
> recent test does prove your point, hence the question "what is the 
> best combination of hw and sw?".
>
Guess the best would be if you could/would be able to limit the possible 
number of recordings on a single card (or one would be able to set a 
limit for FF Cards or a fixed limit would be set in VDR at compile time) 
Then you could have a combination of FF and budget cards like most here 
have most likely.



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