GPU LL Testing FAQ

[Primeinator]

Originally Posted by legendarymudkip

The dlls have to go in the cudalucas folder.

Edit: I removed them from their unzipped folders and moved them to a single folder with just the .exe for CUDALucas.

The program opened a window then went away too fast to be able to read the screen (looked like the command prompt screen though). This to me seems like it worked, but how do I open the program and tell it to start slaving away on an LL test/give it a command line? I forgot to mention that I also added a text file to the folder and renamed the file extension to .bat as mentioned on page 1 of this thread even though the image below does not show it.

Edit 2: I also have reserved an exponent manually.

Thanks!

[legendarymudkip]

It showed up a message about a lack of worktodo.txt. To get it running you can either create a worktodo.txt with some work in the folder or cd to the folder in command prompt and run $executablename $exponent.
Replace $executablename with the name of the cudalucas executable and replace $exponent with the exponent you want to test.

[Primeinator]

Originally Posted by legendarymudkip

It showed up a message about a lack of worktodo.txt. To get it running you can either create a worktodo.txt with some work in the folder or cd to the folder in command prompt and run $executablename $exponent.
Replace $executablename with the name of the cudalucas executable and replace $exponent with the exponent you want to test.

That got it working. Thank you!

Now in the .bat file to get it to have screen outputs every 'x' iterations do I need something like this:

CUDALucas.cuda3.2.sm_13.WIN64.exe -t -c10000 7117xxxx ?

Edit: the above worked

The program does seem to be slowing my computer down though :/. That's ironic because running 4 LLs doesn't even touch the performance (zero difference between running and not).

[legendarymudkip]

The LLs are idle priority, so they don't take up anything else that's trying to use it at a higher priority. However, it's more obvious when the GPU is in use, even by lower priority programs.

[Primeinator]

Originally Posted by legendarymudkip

The LLs are idle priority, so they don't take up anything else that's trying to use it at a higher priority. However, it's more obvious when the GPU is in use, even by lower priority programs.

Fair. If it gets bad and I need to temporarily halt the program what command would I use? I assume there is no way to throttle it?

Last question (I hope!): Where is CUDALucas saving its results?

Thank you for all of your patience! In lieu of being able to buy you a beer in person -- -- a digital one will have to suffice.

Unfortunately I can't really contribute to users asking questions as my knowledge base doesn't extend to cover programming/mathematics. Perhaps we need a Cell/Molecular Biology sub-forum? Haha

[legendarymudkip]

ctrl+C will stop the program and save progress. The savefiles are made in the cudalucas folder.

[LaurV]

As said, P95 runs at idle priority, but you can also launch cudaLucas as so. You may want to use "start /low blah blah" for that.

Open a command prompt on your computer (from start, run, type "cmd" in the open box, and hit enter).
In the command prompt window type "help start".

What you would need in the batch file would be something like: (but read about it first, before trusting me)

start "first cuda lucas instance" /D folder /LOW cudalucasexecutable.exe

Assuming the ini is right (so you don't need additional parameters) and all the dlls in the folder, this will do it. The "first blah blah" is the title that appears on the window and is only useful when you have many instances running (many gpu cards), to distinguish which and where.

Where is CUDALucas saving its results?

General advice: read the content of the .ini file that comes with cudaLucas. Don't be afraid to do changes in it to fit your system. Run the "tuning" part described there. Type "cudalucas /help" at the command prompt (where cudalucas is the name of your executable) to get details how to tune it for FFT and threads, for your particular card and system. You will be surprised about performance improvements.

Then start small, like for example, verifying if exponent 859433 is prime. It will take a very short time to do this check, and then you know if the system works, how it works, where it saves the results, etc.

After that, is time for production. Start a couple of DC assignments (real ones). This way you can verify the residues (with the already reported first-time tests on PrimeNet/GIMPS) and know if you can produce reliable results. If this works, and you think that your card is enough fast (is up to you, and your patience, electricity budget, etc) switch to first time LL. That is where the money and the glory (only if you find a prime, hehe).

[Primeinator]

Thank you, LaurV. I should have done that to start.

I think I have an issue with the save file:

I hit the 'x' on the CUDALucas window, then reopened it later and it restarted from the beginning "iteration 26" trying to find the appropriate FFT length. This implies to me it was not saving the previous several hours of progress??

I should (after this test week) do the tests that you were talking about, LaurV, so that I know how it saves data, how it works, etc.

[legendarymudkip]

It will only save data if you press ctrl+C in the command prompt. Closing it by the X before the program has finished (instead of using ctrl+C to halt the program) will mean that you lose progress.

[LaurV]

Additionally, it will save every "checkpoint iterations" iteration. See the ini file.
If you set it to 1 million (or, if you have disk space, even lower), then you lost mostly a (half) hour of work or so (in case your computer crashes or you hit the red "x" button)

[Primeinator]

Originally Posted by LaurV

A

Then start small, like for example, verifying if exponent 859433 is prime. It will take a very short time to do this check, and then you know if the system works, how it works, where it saves the results, etc.

Okay. Now that test week is over I am doing this. M(859433) is merrily being crunched by my GPU; however, it doesn't appear to be saving progress. I created a results.txt file in the same folder as CUDALucas. I am still obviously missing something

Edit: To clarify, pressing control+C does in fact close the program; however, upon restarting the program it starts the test from the beginning.

Edit 2: CUDALucas does not appear to write either to results.txt or create any new files to save results.

Edit 3: Running the program again I watched until the end of the test. When it finished CUDALucas closed. I checked the folder and alas, there was no edit made to the results.txt or any new file added displaying the result.