[mythtv-users] 2 analog capture cards pushing AMD64/3200 to >=100%?

Poul Petersen petersp at mail.alleft.com
Fri Jun 24 20:46:09 UTC 2005

> Now, in these last couple of days I've solely been struggling to get
> audio working.  Finally, it looks like that's a go.  However, during
> this testing, I see the system crawling.  The backend is sucking up
> ~55% of CPU time (according to top) for a single recording for a
> single card.  But I've got 2 cards, and I expect this machine to also
> be a FE for HDTV.  Yes, the cards are cheapo analog cards using bttv
> drivers (WinTV Go cards).  But I thought if I spent the money on a
> decent CPU, I wouldn't have to worry about the amount of cycles
> absorbed by the lesser card.

	Hmm. That does seem a little high for a frame grabber, but
then it all depends on what settings you are using. I've got a
XP 2200+ with two WinTV Radio cards (and an Air2PC card incidentally).
I have the bttv cards set to capture 480x480 Mpeg4 and when they
capture they use about 38% of the cpu each. 

	Personally, I'd ditch the bttv cards and get some flavor
of PVR. I had weird crashes that seemed to be the result of
starting simultaneous bttv recordings on a single backend. 
When I "stripped" my bttv cards across backends, the problem
lessened, but every now and then I would be recording three 
shows at once (so at least two on one of the backends) and it
would blow up (not everytime mind you - and if I rebooted the
machines regularly it would further lessen the problem) But since
I added a PVR250, my machine has been up for months. I'll
probably buy a PVR500 or two shortly and throw away my WinTV


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