[mythtv-users] *Solution* Capture Card Power Requirements

[James Crow]

James Crow wrote:
> Greetings all,
>
>
> Short question: Does anyone know what the power requirements for PCI 
> capture cards are?
>
> Long version with background:
> I am having some problems with my Myth backend. My initial thought is 
> PSU related, but I wanted to tap some of the smart minds here.
>
> I have an AMD Athlon 64 x2 3800+ (89W TDP) on an ASUS nForce 4 based 
> motherboard. The system has 5 hard drives, two Pinnacle 800i ATSC/QAM 
> tuners as well as a PVR-500 tuner. The PSU is an Antec 430 watt with 
> 28A on the 3.3V, 36A on 5V, and 26A on 12V.
>
> Everything was working fine until I added a 500GB Seagate drive and 
> the PVR-500. Both components were working fine in another system, but 
> I wanted to consolidate both my BE machines into a single system. Once 
> I added those two components I booted back up and walked out the door 
> for four days. The system ran fine and recorded during that period.
>
> When I returned the system started experiencing hard locks quite 
> frequently. The system will boot sometimes and others it will hard 
> lock. If the system boots all the way the first FE that tries to 
> connect hard locks the BE. I first thought that the 12V rail might be 
> overloaded. The Seagate drives need 2.8A on 12V so I should need only 
> 15A for all 5 hard drives. That should leave plenty left over for the 
> rest of the system.
>
> That leaves the 5V and 3.3V rails. The CPU should pull from the 3.3V 
> rail and the PCI cards may as well. I am not sure how to tell which 
> rail they pull from and how much power they need.
>
> If anyone knows the power requirements of the Pinnacle 800i PCI 
> ATSC/QAM/NTSC capture card I would like to know. I also want to know 
> how much power the PVR-500 needs.
>
> Of course I may be chasing a ghost with the PSU. The system is plugged 
> into a APC battery backup that should filter any power spikes or other 
> power issues. The cable input is not filtered, but is grounded 
> (multiple places). I could have gotten a surge through it, but all 
> recorders work. Two weeks ago lightning struck a tree ten feet away 
> from the house, but I have seen no issues with any electronics inside 
> the house.
>
> Any thoughts welcome.
>
> Thanks,
> James
After several helpful replies I found two problems with my setup.

1) The Antec PSU (vintage 2004 I think) had at least two bad caps. I 
have no idea if it caused any other problems. It has since been replaced 
by an OCZ 600W 80 Plus unit. I am now drawing 118 watt at idle vice ~145 
watt with the Antec. Probably will save me $2/month in power. Not enough 
to pay for the supply, but at least I have stable power now. In a few 
months if finances permit I plan to replace three existing hard drives 
with a 1TB or 1.5TB unit. That will drop my power draw a little as well.

2) My PVR-500 card still causes lockups  even with a good PSU. I have 
removed it from the machine and the system was stable all weekend. My 
digital tuners can record analog cable as well, but the quality is 
nothing close to what the PVR-500 could do. I will start a new thread 
asking for help on getting a better picture from the v4l tuners.

Thanks,
James