[mythtv-users] 2 of 3 HD-5500 cards seen on power up, all 3 on reboot?

[Tom Dexter]

On Fri, Oct 8, 2010 at 8:18 PM, Brian Wood <beww at beww.org> wrote:
> On Friday, October 08, 2010 06:05:17 pm Tom Dexter wrote:
>> This one's been driving me insane forever.  My backend has three
>> HD-5500 cards.  When I power up, without fail, it sees only two of the
>> three cards.  However it always sees all three on reboot...drives me
>> nuts.
>>
>> Any idea what could be causing that?  I always figured it was some
>> sort of anomaly regarding power or something.  I was hoping there
>> might be some sort of udev configuration that might affect this.
>>
>> At a bare minimum I'd like to at least know if there's a udev command
>> I could use to find the card without rebooting.
>>
>
> Is this something new? Did it work properly once?
>
> If it worked once:
>
> First thing I'd start looking into is a PSU problem. Those cards draw a fair amount of power (for a non-graphics PCI
> card). The PSU might be struggling to power them all, and might take a while to do so. The voltage might drop while the
> drives are spinning up, and be OK after they are all up to speed, and you might have a card that's not happy with the
> sagged-down voltage. On a reboot, the drives are already spinning, and would not pull the voltage down as much when
> rebooting.
>
> If you have anything you call pull to reduce the total power draw, see if that makes a difference.
>
> Might also be interesting to run lspci when in the "failed" condition, to see if all 3 cards are seen.
>
>
> If it never worked correctly, there might be an issue with process timing at boot up.
>
> This is just speculation, but experience tells me that most "odd" problems are often PSU-related.
>
You're probably correct.  I'm pretty sure the issue used to be
sporadic whereas now it always happens.  A couple of years ago I has
the PS go and replaced it in a hurry with what I know know is probably
a pretty cheap power supply.  It's a 400W PSU where the original Dell
was only 250 I believe, but it is more a less a cheap-o.

I've been thinking about replacing it with something good.  You're
also right that I should power up and see if lspci sees it.

Tom