Experiences with RaspberryPI system loads?
(SOLVED, looks like the issue was SD Card related)
I have been turning my attention to some raspberrypi basestation development and have been a bit hampered by high system loads and I wonder if we could collect data on this from several pi's running the default setup: http://wiki.openenergymonitor.org/index.php?title=Raspberry_Pi
I have 4 wireless nodes: 3 low power temperature nodes posting every 20s and 1 emontx posting every 5 seconds. Which means there can be several new packets arriving in a short space of time.
Im currently logging only two inputs to feeds with one multiplication by 0.01 to scale down a x100 temperature reading. Which is a relatively small amount of input processing
With sudo top I get a 1 minute, 5 minute and 15 minute load of ~ 4.17 4.09 3.93. With the 1 minute load generally variable from 3.3 to 5.0. This level of load makes the pi quite sluggish, although it is possible to load and explore visualisations with a slow response time.
I had this result last thursday and at the time started exploring different ways of implementing the input stage. To begin with the load seemed to go down to around 2.5 but 3 days later it was up at 6-7. Changing back to the current implementation put the load up higher still.
Back to the drawing board, determined to take better notes this time, I have started again with a fresh sd card install and the loads appear to be back around 4.17 4.09 3.93 with about 12 hours of logging so far.
What are your experiences with raspberrypi +rfm12pi + emoncms system loads? If you can give details of number of nodes connected and level of input processing that would be great.
Thanks,
Trystan
Re: Experiences with RaspberryPI system loads?
Trystan, you don't mention anything about overclocking, I have mine overclocked and it works pretty snappy now. I haven't tested with sudo top, will have to try.
Re: Experiences with RaspberryPI system loads?
Hello Martin, thats interesting, no I haven't, what's the best procedure for doing that?
Re: Experiences with RaspberryPI system loads?
It's part of the rasppi-config of raspbian. Run rasppi-config and select overclock.
Re: Experiences with RaspberryPI system loads?
Thanks! what level do you set it at?
Re: Experiences with RaspberryPI system loads?
The recommendation on the RaspberryPi Forums is to slowly increase the overclock setting, and only when the Pi has run stable on one setting, under heavy load (try Quake3), should you try the next higher setting to see if that also works well.
There are some reports that it can corrupt the sd card (card can't keep up!) and make the Pi more sensitive to power.
Re: Experiences with RaspberryPI system loads?
Its looking like it might have been an SD card problem, I have just tried a SanDisk SDHC 16gb Grade 4 Card and the loads are now much lower 0.50 0.48 0.24 with the exact same input setup. The SD cards I was using where kingston sdhc 4gb grade 4 cards.