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

[James Crow]

Michael T. Dean wrote:
> On 08/24/2009 02:22 PM, James Crow wrote:
>> 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.
>
> 80 PLUS ftw!  I saw similar savings (though my before/after were a bit 
> lower): http://www.gossamer-threads.com/lists/mythtv/users/371460#371460
>
> Note, also, that 80 PLUS only guarantees 80% + efficiency from 20% to 
> 100% load, so if you're only drawing 118W, you're just under the 20% 
> marker.  I recommend getting the 80 PLUS lab tests for the specific 
> PSU you're using to see if that's A Bad Thing.  Although they don't 
> test at below 20%, you can usually extrapolate for a "small" interval 
> beyond the 20% load line:
>
> http://www.80plus.org/manu/psu/psu_join.aspx
>
> I'm guessing: 
> http://www.80plus.org/manu/psu/psu_reports/SP169.1_OCZ_OCZ600MXSP_600W_Report.pdf 
>
> which wouldn't be too bad to use with your current draw, though a 
> lower-power PSU might actually increase efficiency by a percent or 2.  
> And, if you do decrease the number of HDD's (or otherwise reduce power 
> requirements), you may actually use more total power due to efficiency 
> losses (as many PSUs--even the 80 PLUS units--tend to lose efficiency 
> quickly when "out of range")...
>
>> Not enough to pay for the supply, but at least I have stable power now.
>
> Not in the short term, but...  ;)  Note, also, that it's not difficult 
> to find 80 PLUS PSU's in the $40 and lower range if you buy when 
> they're on sale.  I've bought all 7 of mine for $29.99 or $39.99 with 
> free S&H.  Mine are also all 400W-430W PSU's.  At that rate, saving a 
> couple dollars per month can recoup cost before too long.
>
> I'm not saying it's worth replacing your brand new PSU at your own 
> expense for the efficiency savings (even for those who are using 
> non-80-PLUS-PSUs).  However, if you need to replace a PSU for another 
> system that uses more power, you might want to buy a smaller PSU and 
> use it for this system, then put the OCZ 600W in the other system.
>
> Mike
>
That is the supply I have, Mike. The 118 watt is from idle with no 
recordings/comm flagging/other power draining activities. This system is 
fairly busy round the clock so I expect the power usage to climb higher 
once it is in back in full production.

I recall reading your posts about replacing your PSU's with 80Plus units 
and decided at that time to wait until my PSU died. I'm not sure if it 
was you or another poster that had a thread about the power required to 
transcode versus just installing another disk. That was an interesting 
read.

I could have gone with a smaller PSU, but I plan to upgrade to a newer 
quad core system and may need the extra power.

Thanks,
James