[mythtvnz] FrontEnds Controlling Audio Mains Power

[Tortise]

----- Original Message ----- 
From: Steve Hodge
To: MythTV in NZ
Sent: Wednesday, October 06, 2010 10:12 PM
Subject: Re: [mythtvnz] FrontEnds Controlling Audio Mains Power


On Wed, Oct 6, 2010 at 9:29 PM, Tortise <tortise at paradise.net.nz> wrote:

>>I measured the full off mains power current from a (FE) desktop PC.  Much to my surprise it is a full 25 W (0.11A) when off.

>That seems unusually high. Mines showing a peak 0.05-0.06A, 11-14W. I'm using one of these to measure: 
>http://www.dse.co.nz/dse.shop/4cac38c201b747b82740c0a87f3b06fb/Product/View/M7319

A 2nd 3G Intel box is same, both gigabyte motherboards.

>What make is the powersupply? What's the motherboard? My guess is that one of those two is to blame.

>>Measuring tool: Fluke 73 Digital multimeter. A brief on test to the mythtv menus pulled 130 to 200W.  (460W PS, 3G Intel CPU and
9400 GT PCI)  Sorry I should have run some HD as well....

A 3.1G C2D FE idles at 0.28A and plays 1080i at 0.32A. (A mere 74W, which surprises me, as I thought it would be much more!  That is 
50% power saving over the 3G single cores!!!)   Suspend and off power is 0.05, as for Steve, so it maybe the motherboard / CPU class 
that determines the idle load?

All machines I reported on have CF HDD and 9400GT's in the single core boards and a 8500GT in the Dual.

>On my machine copying a 4GB file from an SSD to a mirrored pair of SATA drives added approximately 20W to the consumption. Pretty 
>trivial in comparison to the CPU or GPU.

Perhaps, but it is also double that of an idling vdpau card vs it playing 1080i, which surprises me.  Were the drives off before the 
copy?.

BTW if anyone wants to know another easy and safish way to do the measurement, (Steve's tool is probably good also!) I cut some 
probes off a test lead set and wired them into a "Plug Top Interrupted Phase Tapon" which makes it easy - just plug in much same as 
Steves kit.