PrimeGrid Races 2018

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StefanR5R

Elite Member
Dec 10, 2016
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The August 10-13 Solar Eclipse Challenge results went final earlier today.

Top 6 team stats, and deductions of invalid tasks during the cleanup stage:

1 ... Czech National Team ...... 11,515,077.92 ..... (-3,676.79)
2 ... Aggie The Pew .................. 10,883,409.65 ........ (-160.51)
3 ... SETI.Germany ..................... 9,147,840.90 ........ (-800.61)
4 ... TeAm AnandTech ............... 7,332,960.63 ........ (-319.91) — that's 2 invalid tasks, and OK in my book
5 ... Sicituradastra. ..................... 4,187,374.12 ........ (0)
6 ... Crunching@EVGA ............... 3,737,656.56 ........ (-320.12)

(Rather than doing the math myself, I stole the numbers from pschoefer.)
 

Ken g6

Programming Moderator, Elite Member
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Thanks, Stefan!

I just noticed that big GFN race (say that three times fast) in December is going to be a long one, in the middle of our F@H race. :(

But for now I updated the OP for next week's race.
 

Ken g6

Programming Moderator, Elite Member
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We're off! An hour and a half ago. Nobody replied to this yet?
 
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zzuupp

Lifer
Jul 6, 2008
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We're off! An hour and a half ago. Nobody replied to this yet?
oops. Thanks for the heads up. I've switched one box over. I'm letting it run out of it's TN-Grid cache. So, sometime late tonight or very early Sunday morning it will be really in.
 

crashtech

Lifer
Jan 4, 2013
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The earlier than customary end to the Sprint caught me flatfooted, but I'm correcting course now...
 
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Ken g6

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Day 1 stats:

Rank___Credits____Username
31_____95560______Howdy2u2
50_____63092______Ken_g6
88_____16659______crashtech

Rank__Credits____Team
7_____373322_____Crunching@EVGA
8_____236316_____The Scottish Boinc Team
9_____225088_____The Knights Who Say Ni!
10____175312_____TeAm AnandTech
11____127135_____L'Alliance Francophone
12____126280_____BOINC@Poland
13____110241_____BOINCstats

Well, I guess 10th is OK with just three of us. I hope things pick up now that the FB sprint is over.
 

Markfw

CPU Moderator, VC&G Moderator, Elite Member
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May 16, 2002
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Is the TN-grid race over ??
 

StefanR5R

Elite Member
Dec 10, 2016
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Well, I guess 10th is OK with just three of us.
Obviously you three manage just fine.
You already worked your way up to 8th!
Oops, I looked at outdated stats... now you are 11th. :-|
Rankings are still rather volatile with these long task runtimes.
 

Rudy Toody

Diamond Member
Sep 30, 2006
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I'm on PG, but my 16 WUs still have 7d10h to go. I'm not even sure they will upload in time.
 

Ken g6

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I'm on PG, but my 16 WUs still have 7d10h to go. I'm not even sure they will upload in time.
If you are running with hyper threading, suspend or abort two or three tasks.

Edit: Better make that four.
 
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Ken g6

Programming Moderator, Elite Member
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It's a Ryzen. It has SMT. Should I change ncpus?
Go to Options -> Computing Preferences in BOINC Manager. On the Computing tab, set "Use at most ___% of the CPUs" to 75.

Edit: Or suspend all but 12 PrimeGrid WUs.
 
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StefanR5R

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Dec 10, 2016
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@Rudy Toody, @lane42, llrCUL needs to be run multithreaded (i.e. with several program threads per task; not to be confused with HT or SMT which is two hardware threads per processor core).
If you run it singlethreaded, which is the default, the processor caches are insufficient, and total host performance tanks.*

Enabling multithreading means you can run only fewer tasks at a time. But each task is accelerated more than you lose by having fewer tasks. IOW total host throughput goes up. And with heavily decreased task run times, you may also be able to fit more tasks into the challenge's time window.

The challenge thread http://www.primegrid.com/forum_thread.php?id=8194 has an app_config.xml example for 4 threads per task.**

Intel 4-core i7 of Haswell and later run best with HT on and one task at a time, and 8 threads per task is probably the best config (with 7 or 6 threads per task having similar performance). I don't know what the best config for 6-core i5 Coffeelake is (2 tasks at a time with 3 threads each, or 1 task at a time with 6 threads; I suspect it is the latter).

I have no idea what the best config for Ryzen is. But even if you shoot in the dark and run 2 tasks at a time with 4...8 threads per task, performance should be quite a bit better than 16 tasks at a time with 1 thread per task (or than 12x1 for that matter).

--------
*) In other words:
1st) The number of tasks per processor socket needs to be limited.
2nd) While running only few tasks, give each task as many threads such that all or nearly all hardware threads are utilized.

This applies to all LLR subprojects with longer CPU times. They only differ somewhat in regard of the precise sweet spot of task count per socket, especially on many-core/ large-cache processors. On processors with few cores and respectively small cache, the sweet spot soon becomes 1 task at a time as you go from one LLR subproject to another in order of increasing CPU time.

--------
**) After you edited /var/lib/boinc{,-client}/projects/www.primegrid.com/app_config.xml, do a "sudo service boinc-client restart". You can do this safely even with already running LLR tasks; they will be resumed at their current completion percentage after the restart, but with the new cmdline parameter applied.
 
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StefanR5R

Elite Member
Dec 10, 2016
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By the way, to those who try different app_config settings (or look at forum posts of others who tried different settings) and how they affect task run times:

According to a post in the challenge thread, there are llrCUL tasks with different FFT sizes out there. This means that they will have different run times with same app_config settings. (The longer tasks will also get proportionally more credits per task.)

In other words, due to variability between tasks, comparing the performance of different app_configs based on run times alone is imprecise. One rather needs to compare based on PPD.

On the other hand, even if you miss the very best config, any reasonably good config should be quite close in performance to the best config. No need to lose sleep over this. :-)
 

biodoc

Diamond Member
Dec 29, 2005
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It's a Ryzen. It has SMT. Should I change ncpus?
With a Ryzen, I would leave SMT on and run 8 threads per task. To do that you'll need an app_config.xml in your www.primegrid.com directory.

<app_config>
<app_version>
<app_name>llrCUL</app_name>
<cmdline>-t 8</cmdline>
<avg_ncpus>8</avg_ncpus>
</app_version>
</app_config>

Then restart boinc.
 
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Ken g6

Programming Moderator, Elite Member
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Oh, yeah, stats. I've been so busy with work I couldn't think about anything else until now. Late day 2 stats:

Rank___Credits____Username
24_____357283_____Howdy2u2
26_____334264_____xii5ku
34_____295039_____crashtech
57_____142067_____Ken_g6
76_____98399______Orange Kid
87_____81657___10esseeTony
123____47515______Lane42
135____33339______zzuupp

Rank__Credits____Team
4_____3208686____Sicituradastra.
5_____1540755____BOINC@MIXI
6_____1443296____AMD Users
7_____1389567____TeAm AnandTech
8_____1314585____Crunching@EVGA
9_____946174_____The Knights Who Say Ni!
10____744433_____BOINC@Poland

We're making good progress! Assuming no late surprises (which are very likely to happen, actually) we could reach 5th! :)
 

lane42

Diamond Member
Sep 3, 2000
5,697
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Got the app_config. file in. Its using 6 cpu's , on a core i5, for 1 workunit. Much faster. The progress
bar in Boinc manager moves every 10 seconds now not 10 min.:)
How can I get it to run more then 1 workunit at a time.
 
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Ken g6

Programming Moderator, Elite Member
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How can I get it to run more then 1 workunit at a time.
On a Core i5 I don't think you want to. You could try setting it for 3 cores, I guess, but that would probably be worse overall. This is a Coffee Lake i5, right?
 

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