PrimeGrid's Diwali/Deepavali Challenge (challenge 6 of 8 in the PrimeGrid Challenge series)

Gilthanis

Gilthanis

[H]ard|DCer of the Year - 2014
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http://www.primegrid.com/forum_thread.php?id=7623#110693

The sixth Challenge of the 2017 Challenge series is a 5 day challenge to celebrate Diwali/Deepavali. The challenge is being offered on the The Riesel Problem (LLR) application.

To participate in the Challenge, please select only the The Riesel Problem (LLR) project in your PrimeGrid preferences section. The challenge will begin 18th October 2017 00:00 UTC and end 23rd October 2017 00:00 UTC. Note the non-standard start time.
Any prime we find in this challenge would be the first TRP k we will have eliminated in over 3 years!

Tips:
You must log into your account at PrimeGrid to change your project preferences so that you are only crunching the correct sub project. In this case The Riesel Problem LLR.
Intel boxes tend to perform better. The HT probably needs turned off since these are LLR work units. Do your testing in advance.
Intel chips tend to out perform AMD chips
PrimeGrid work will stress hardware harder and so is more sensitive to overclocking. Therefore make sure you have tested their work units on your rigs before the challenge to make sure they are stable.
These challenges only count work units downloaded during and completed before end of the challenge. So, no bunkering.

Multi-thread app_config.xml

<app_config>
<app>
<name>llrTRP</name>
<fraction_done_exact/>
</app>
<app_version>
<app_name>llrTRP</app_name>
<cmdline>-t X</cmdline>
<avg_ncpus>X</avg_ncpus>
<max_ncpus>X</max_ncpus>
</app_version>
</app_config>

Change X to the number of threads/cores you want each work unit to use.

Team page - http://www.primegrid.com/team_display.php?teamid=1710
 
Last edited:
For anyone new to this, I'd add that you need to put that app_config.xml file in the PrimeGrid project folder. On my Windows 10 install it is here: C:\ProgramData\BOINC\projects\www.primegrid.com\

I'll be doing this challenge. I don't have any tasks under The Riesel Problem, so this will be a good excuse to get some points toward my silver badge goal in all of their subprojects.
 
Here are some random total cpu times in seconds. We know nothing of the computer's RAM speed, or what else was running while it was processing these tasks. If you setup the threaded app_config.xml file then you could expect approximately to divide these times by the number of CPU cores you have. All three tasks were run threaded based on the task details, so if it was run single threaded then the actual total cpu time would be a bit faster.

The LLR software is sensitive to RAM.

i7-4790 CPU @ 3.60GHz 34,669 I think this computer has fast ram. i7-7700k processors return times around here plus or minus 5k seconds.
i7-7820X CPU @ 3.60GHz 50,896.55
i7-3930K CPU @ 3.20GHz 89,000 seconds
i7-x5670 CPU @ 4.00GHz 194,524 seconds This is my computer. Has no support for the AVX instructions, so it is SLOW.

Here is link to a recent TRP work unit. You can click on the computer link, and then see their list of tasks, click TRP and you'll get a whole list of TRP tasks for that computer. The tasks that say validated will have a second computer on them, and you can look at their speeds and computer specifications. Etc. That is how I got the above numbers.
 
Is the xml file required. I turned off hyper threading on my Windows machine but the Mac I just updated the preferences to only use 4 cores as you cannot control hyperthreading by default.
 
Is the XML file required?
No

Do you need to have the threading on the CPU turned off or have it on?
Either is OK.

For this challenge, would it be helpful to have the the xml file in the folder with the TRP setting set?
Yes, since this challenge is over in 5 days. You have a higher chance of completing more tasks before the ending deadline if the task gets done quicker by breaking it up over multiple threads. With a 4 core processor the total task time with drop to somewhere between a 1/3rd to 1/4th of the time -- but only one task will be running at a time.

In the case of a computer with 4 cores use this:
<app_config>
<app>
<name>llrTRP</name>
<fraction_done_exact/>
</app>
<app_version>
<app_name>llrTRP</app_name>
<cmdline>-t 4</cmdline>
<avg_ncpus>4</avg_ncpus>
</app_version>
</app_config>

This challenge is a good way to get acquainted with the PrimeGrid project and one of its sub projects. Any of the projects that end in LLR can be threaded similar to the above app lines. The other lines for different sub projects go in the same app_config.xml file and would be added between "</app_version>" and "</app_config>"
 
Thanks, I did not know of the lift you get from running one project on 4 cpus. I will set up my cpus, although the mac is questionable as it loaded but still ran only one task per thread. It may be due to the task already being started and not a new task with the config file.
 
skylaar24 said:
Thanks, I did not know of the lift you get from running one project on 4 cpus. I will set up my cpus, although the mac is questionable as it loaded but still ran only one task per thread. It may be due to the task already being started and not a new task with the config file.
Click to expand...

When you create the file in the folder you will want to turn off Boinc Manager and restart to reload the configuration files.

You want to make sure that you are getting new tasks after 7:00PM CDT, so they get flagged for this competition. If you have tasks already, you can wait till 7:00PM and increase your cache to 6 days, and let it download more. Then select the original task and suspend it (if you already processed a bunch) and or abort that one.

Running the tasks multithreaded takes a task that might take 20 hours each on one thread, when you change it to 4 threads it might take 5 hours 20 minutes. So it gets done faster, but there is some inefficiency.

If you don't know about it, I like using the advanced view in boinc manager. To turn it on choose Options->Advanced View.

Make sure to abort any tasks you might choose not to run.
 
Yes, I like the advanced view. The app_config does not seem to work on the Mac. I get a notice upon loading Boinc stating the app_config file is missing <app_config> even though that is the first line. I have no prior tasks as they have been crunching SR Base. I will switch both Mac and Intel to PrimeGrid at 7pm. Testing on the Mac took 17 - 20 hours per task.
 
How is this one going for everyone? I had some errors getting the multi-thread piece working but now I have my laptop (set at 3) and i7 920 (set at 4) using the config. The mac is just running 1 task per CPU on 4 CPUs.
 
It is going OK. Was at work during the switchover. Signed into the site and picket the TRP tasks at 7CDT, and whatever GCW tasks were running completed around 8, then the TRP task took off.

The PrimeGrid project is hoping to find a prime during this challenge with the help of all of the extra computers. A TRP prime hasn't been found in 3 years, and if a prime is found it will eliminate one of the K numbers the project has to process through.

Heavy reading
The Riesel Problem: Definition and Status
The Riesel Problem - Wikipedia
 
Due to preparing to move, I will not be moving much around for this challenge.
 
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