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1) Message boards : Number crunching : Beta testing of PRST app is open on "GFN Server" (Message 159690)
Posted 58 days ago by stream
FFT has grown again. Now optimal mulithreading setup is 3 or 4 cores, depending on your CPU.
2) Message boards : Number crunching : Beta testing of PRST app is open on "GFN Server" (Message 159304)
Posted 72 days ago by stream
New version of application (1.03) is installed for both Windows and Linux. It should fix an issue with restart from less efficient (older) checkpoint.
3) Message boards : Number crunching : Beta testing of PRST app is open on "GFN Server" (Message 159303)
Posted 72 days ago by stream
It's time to enable multithreading!

It was a surprise even for me, but FFT method used for factorial and primorials is not only slower that standard Proth / Riesel tests, but also consumes two times more cache memory!

The formula for factorials / primorials is:

Cache_usage = FFT_SIZE * 16

It means that standard desktop CPUs with 6MB or 8MB cache should switch to mulithreaded mode. For few days, two threads should be enough, than it'll better to use 4 threads when FFT size exceeds 256KB. I'll keep you informed when it happens.

Multithreading is available using app_config.xml. It's located in project directory - <boinc data directory>/projects/ It should be plain text file with following content:

<app_config> <app_version> <app_name>prst</app_name> <cmdline>-t 2</cmdline> <avg_ncpus>2</avg_ncpus> </app_version> </app_config>

If the file is already there with other setting, just add <app_version> block (without <app_config> tags). Change number of threads (2) to other value if necessary. Save the file and reload configuration files in Boinc client or restart the client.

4) Message boards : Number crunching : Beta testing of PRST app is open on "GFN Server" (Message 159262)
Posted 74 days ago by stream

Then a few questions:

How many units to Double Check?

There are 176500 factorial tests from N=50K to N=300K (current PrpNet leading edge). Everything below 50M was tested manually. It's quite significant amount of work because factorials are growing very fast, both FFT size and runtime will be greatly increased soon. We jumped from 50M to 100M in 24 hours or so, but it'll slow down soon.

You seem to start with factorial primes easier to test, primorial tests to follow?

I just didn't preprocessed primorials yet. As soon as data will be ready, I'll load primorials as well. Probably task will be sorted by FFT size, so both types of primes will be tested at same time and tasks will have similar runtime.

I guess it is not DC until TdP starts in February?

I'm sorry but I didn't understood the question fully. Factorials and primorials (if any missing primes will be found) will not acceptable for 2023 TdP because this test project is running on other server. The goal is to run full-scale Boinc search on PrimeGrid, but it definitely will not happen before February.

They are both megaprimes if we start from where PRPNet are today?

Yes, both projects will be mega-primes.
5) Message boards : Number crunching : Beta testing of PRST app is open on "GFN Server" (Message 159256)
Posted 74 days ago by stream
Seeing all failed tasks ... across my various Windows hosts

Some with error 255 (0xff) Unknown error number
Others with error -1073741795 (0xffffffffc000001d) Unknown error number
ALL crash/fail within a few seconds of starting up.

I've installed new Windows build, hopefully it'll fix the program.

Look like previous version was erroneously built with AVX instructions, which are not supported by your CPU.
6) Message boards : Number crunching : Beta testing of PRST app is open on "GFN Server" (Message 159254)
Posted 74 days ago by stream
Just downloaded a batch of tests single core estimate 23 minutes on a 5900x. Does this need a variety of hardware? Should I switch up computers or is the first batch just DC of PSA projects not matter as much?

You can test in any style according to you personal preferences / goals. We need to check how application behaves in real life on a variety of different computers, where users are performing usual daily tasks (pausing / aborting applications, rebooting computer, installing Windows updates and so on), and how server handles data returned by application in these cases. Just run it as long as you want to, and report to forum or Discord if you've noticed something unusual.

Also if we do get a mismatched factorial DC will you be the 3rd party or does it create a 3rd wu?

"fast double check" system will be activated to prove that our task was correct and PrpNet task was wrong. It will create new short "certificate" tasks and send it to somebody. There are some threads/posts on forum which explains how fast DC works in LLR2 (PRST uses same algorithm), so I'll not repeat it here.
7) Message boards : Number crunching : Beta testing of PRST app is open on "GFN Server" (Message 159244)
Posted 75 days ago by stream
I've just created a new project, "PRST testing" to test new prime searching program - PRST.

PRST is a new prime testing program, written from scratch by Pavel Atnashev, author of LLR2. This is still a work in progress, but it's quite stable and basic types of tests are already implemented. The thing most important to us is that PRST can test factorial and primorial primes with fast double-check and Gerbicz-Li error detection.

As an essential step to move our factorial and primorial searches to Boinc, we must test new program and all brand new server scripts in real-life conditions. On the first phase, PrimeGrid PrpNet factorial and primorial work will be double-checked.

The testing will be run on my own "Private GFN Server". It's not on PrimeGrid yet. If you're already registered on my server, just go to preferences and select new application.

If you're not registered yet, you must go to the web page of my server and create an account there. The inviation code is PrimeGrid. Automatic registration from Boinc client probably will not work because, as far as I remember, it was not possible to specify invitation code during built-in registration. After registration, you can attach your Boinc client to new project using URL above.

The program is similar to LLR(2) and is CPU-only. Applications are available for Windows64 and Linux64 platforms.

Multithreading is recommended (currently 3 or 4 cores per task for most desktop CPUs, depending on CPU total number of cores) and supported using app_config.xml. See this post for details.
8) Message boards : Sierpinski/Riesel Base 5 Problem : Welcome to the Sierpinski / Riesel Base 5 Project (Message 158981)
Posted 86 days ago by stream

Let's remove 424 unused tasks for 213988 in statistics page

9) Message boards : Sophie Germain Prime Search : SGS application update (Message 158753)
Posted 97 days ago by stream
I've installed new LLR for Windows and Linux 64-bits applications to fix problems on AVX-512 CPUs.

Technically, executable file was LLR2 but it's running in compatibility mode, there is no Gerbicz check and fast DC for SGS. Everything is working in same way as before.

I've tested LLR2 on few tasks and it seems to produce exactly the same output as old LLR, so I'm expecting it to be a fully transparent replacement. Anyway, please post here if you've noticed something suspicious.
10) Message boards : Number crunching : Great Internet Fermat Prime Search Challenge (Message 158752)
Posted 97 days ago by stream
Where do I start in figuring out discrepancies? and errors? and strangeness?

For strangeness, I checked this morning and had 1 pending job left. Checked this and it looked like it had already been validated by someone else, a long time after I was finished with the task and waiting for validation but is still in pending for me. Just checked now and it's still there . . .

You can post links to strange tasks (or results IDs) here on on discord.

Thank you for your response :)

Result ID: 1420602969 or

The task was marked as invalid because it returned wrong result. It was certificate task, these types of tasks are returning some magic number which must match a secret value expected by server, thus confirming that all computations in the chain were correct. Your computer has returned unmatched value. Same task with same input data was sent to another user, and his result was correct. So it's a GPU hardware failure on your side. Most common reasons of these failures are overheating and overclocking (including factory overclocking). You'll not notice a slightly wrong color of one pixel on the screen, but one corrupted bit during calculations will ruin whole task.

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