S6BucketFU2UB Sawtooth CPU Utilization
29 Apr 2015 10:54:42 UTC
Topic 198072
(moderation:
Hello!
While exclusively processing S6BucketFU2UB WUs (i4770k, 16 GBy RAM, no OC, Win 8.1/64, BOINC 7.4.42, task checkpoints to HDD every 200 sec), I noticed my daily average credit began to drop from a steady 8000 for S6BucketFU1UB WUs to now 7000 and falling (moving average).
While I don't give a rat's B hind about credits, I was curious as to the reason and began investigating.
With other background processes consuming less than 2% total accross all 4 CPUs, I noticed S6BucketFU2UB CPU utilization was following a sawtooth wave pattern:
1. CPU Utilization gradually rising from 20% to 100% during 70 seconds, then
2. CPU Utilization rapidly falling from 100% back to 20% during the next 20 seconds.
While this sawtooth wave is a mere curiosity probably not due to GWs traversing my CPU's silicon, it does mean my total CPU utilization is only averaging (100 - 20)/2 + 20 = 60% and, more importantly, that 40% of my crunching capacity remains unused by science.
Please note previous S6BucketFU1UB WU processing (also exclusively) did not exhibit this strange behaviour.
Any ideas? Anybody else exhibit this trange behaviour?
Cheers,
- jahman.
S6BucketFU2UB Sawtooth CPU Utilization
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Do you by any chance have a setting enabled or run some software which expressly tries to control the CPU temperature? Tthrottle is one such application and gives behavior somewhat similar to that which you describe.
Good call! (And thanks for
)
Good call! (And thanks for pitching in.)
Alas, CPU temps rise and fall (in step with the sawtooth) between 27ºC and 37ºC, so no temperature throttling (CPU is massively watercooled for an OC that I never got around to doing.)
Also as I mentioned "previous S6BucketFU1UB WU processing ... did not exhibit this strange behaviour", and the hardware/software config of my rig has not changed at all.
There is another new symptom I'm noticing: In the BOINC Manager/Tasks tab, the "Elapsed" (time) column for S6BucketFU2UB tasks stutters rather than steadily increment the elapsed time at the expected rate of one second per second (as the SETI@Home task that I'm running on my GPU does, and all previous S6BucketFU1UB tasks did).
Cheers,
- jahman.
Anyone? Please?
)
Anyone? Please?