home page
Posts by Evans CPAH

Posts by Evans CPAH

1) Message boards : Number crunching : "No tasks sent" (Message 62411)
Posted 8 May 2020 by Evans CPAH
This is a clean install of Lubuntu 20.04. CPDN now running happily. The first job started spontaneously, at random. A second started immediately I gave it another core.

There were no similar messages in 19.04.
2) Message boards : Number crunching : "No tasks sent" (Message 62410)
Posted 7 May 2020 by Evans CPAH
The solution is obviously to post to the forum, because I now have a task running...
3) Message boards : Number crunching : "No tasks sent" (Message 62408)
Posted 7 May 2020 by Evans CPAH
Currently getting this response under Linux and BOINC 7.16.6. Status page says there are 1744 jobs available. No other relevant-looking messages.
4) Message boards : Number crunching : Ryzen Performance (Message 58648)
Posted 26 Aug 2018 by Evans CPAH
I didn't bother running CPU jobs on Bulldozer/Piledriver. The poor CPU floating point performance meant that they were better employed running GPU jobs like Einstein. I ran CPU jobs on Intel.

Switching to a Ryzen 2200G has been kind of interesting. Not only is the FP performance in the same ballpark as Intel, but it also meant in this case a healthy jump in memory throughput (to 3000 MT/s). And my hypothesis is that given acceptable FP performance, CPDN is mainly memory bound, not CPU bound. Given that it's a giant matrix that has no hope of fitting in any data cache, that wouldn't be too surprising.

For various reasons, I haven't tested this (CPDN outages, other projects running). But if it's true, it leads to two further observations: first, SMT/hyperthreading will mainly help other (non CPDN) processes, that are not memory bound. They can execute during the numerous cache misses caused by traversing a giant data structure. Second, running your CPU at full speed all the time for CPDN is a waste of power. My results seem (anecdotally) to be similar whether the 2200G is running at 3.6GHz or throttled to 2.4GHz, at a third of the power.

And yes, the 2200G has no SMT. With a lot of experience running BOINC and VMs, and BOINC in VMs, I'm not a big fan.
5) Questions and Answers : Windows : Visual Fortran run-time syntax error (Message 2757)
Posted 2 Sep 2004 by Evans CPAH
Come on, guys.

Win32 4.05

forrtl: severe (17): syntax error in NAMELIST input, unit 57, file

This is the first cp work unit I\'ve (tried to) run. BOINC has not handled this error, thinks the wu is running.