[vdr] power consumption, powertop and wakups per second with a af9015 device, vp7045, and various plugins

Antti Palosaari crope at iki.fi
Tue Mar 24 14:13:25 CET 2009

Heinrich Langos wrote:
> For completeness and comparability:
> The Fujitsu Stick (vp7045) still by far beats the af9015 
> in terms of resource usage with vdr. (13% vs 19% with or
> 37% without hw pid filter) 
> It doesn't seem to hava a hw pid filter ( at least it doesn't 
> react to the force_pid_filter_usage option. so here are 
> the results with the same setup, using the same channels and 
> the same vdr plugins:

vp7045 does not have PID-filters.
I think difference comes from different USB-transfer settings. vp7045 
uses BULK packet size 4096 and af9015 uses BULK packet size 512 for 
USB2.0 and BULK packet size 64 for USB1.1. Therefore af9015 sends 8 
times more packets than vp7045 (I guess).

One thing more you can test - use USB1.1. To force USB1.1 remove USB2.0 
driver by rmmod ehci_hcd. After that plug af9015 stick and look from 
logs it detects USB1.1 and uses PID-filters. af9015 driver now uses 
smaller packet size for transfer that can change load (bigger?).


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