highFreq or lowFreq
22 May 2017 6:03:04 UTC
Topic 207795
(moderation:
Hi
Why are some computers only counting highFreq tasks and not being able to download lowfreq tasks? Other computers only counting lowFreq tasks and not being able to download highfreq tasks. What is going on?
The amount of memory used
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The amount of memory used varies by frequency, from a few hundred MB at the low end to two GB at the high end; the scheduler splits computers into low and high end buckets and sends low frequency tasks to the former and high frequency to the latter.
In the last round of Gravity
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In the last round of Gravity wave work they also split the work into two types. They used CPU cache memory and available RAM to determine which machines could do what.
As mentioned by Danneely the Lo work units are sent to less capable machines. The Hi go to the more capable machines. The Hi work units can use up to 1.8GB of memory each depending on the work unit frequency (above 1420Hz).
BOINC blog
I have a high capacity
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I have a high capacity machine and only see low units.
Nick_43 wrote:I have a high
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"Measured floating point speed:3264.54 million ops/sec"
I'm not sure if that FP speed is considered, but maybe that is not fast enough.
Nick_43 wrote:I have a high
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While the intent is to distribute by capability, I think the actual distinction is made rather simplistically from something as simple as the text string reported as the CPU model, with the matching code built up from early trial experience. I agree it does not always match actual capability.
The distinction between the
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The distinction between the two application is indeed made by the CPU model that is reported by the BOINC Client. You can read more about why this was necessary here: https://einsteinathome.org/content/gravitational-wave-search-o1as20-100-f-and-i-faq
I monitored per task runtimes for both searches and they are in the expected 8-10h range for the majority of hosts in each search.
I would think my 8MB of cache
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I would think my 8MB of cache would be considerable, maybe it isn't these days...
Nick_43 wrote:I would think
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That's a Nehalem EP which was quite a fearsome chip when new. It is no longer new, nor even middle-aged. I've just retired my system which was running a Xeon E5620 Westmere, which is a quick redraft of Nehalem on the next generation manufacturing process (32 nm down from 45 nm for yours).
The proof of the pudding is not in any single parameter, but in elapsed time to finish a WU of a given type. You appear to be generating valid 1Spot1TLo work with elapsed time in the 40,000 to 50,000 second range. That is not markedly fast.
For comparison, my Skylake laptop, which is running a single instance of THi is finishing them in about 34,000 seconds. I consider that surprisingly fast. Perhaps this application likes Skylake for some reason.
My Sandy Bridge desktop, my oldest model in continuing service, is being giving Thi work and finishing them in about 33,000 seconds. Again this is single instance.
My Haswell desktop, which is more modern than the Sandy Bridge model, but an i3 variant, which may distract the selection method, is getting TLo work and finishing them in about 25,000 seconds, also on single instance (but supporting two GPUs, which keeps the two physical cores of that chip pretty well occupied).
My Devil's Canyon desktop which is my most capable machine, but a generation less modern than my Skylake laptop, ran some THi work in about 32,000 seconds, but I stopped that work type the better to support my two most capable graphics cards on that host.
Nick,
Boinc reports your host as having 16 processors. But Intel lists that CPU as a four physical core part with hyperthreading. Are you running a motherboard with two CPU sockets? Plus have hyperthreading turned on?
ARCHAE86 Boinc reports your
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ARCHAE86
Boinc reports your host as having 16 processors. But Intel lists that CPU as a four physical core part with hyperthreading. Are you running a motherboard with two CPU sockets? Plus have hyperthreading turned on?
Yes to all of the above.
The X5570 also does not
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The X5570 also does not support AVX, so that may also be a factor.