CPDN was running successfully on my computer until 2014-10-24.

I moved BOINC's data directory from my SSD to my HDD a few days ago. I started this process first thing on 2014-10-25, and finished the process on 2014-10-28.

That appeared to have been successful, with new tasks downloading, running until complete, and then uploading.

However, it's been running in that configuration for a couple of days now, and all of the CPDN tasks that I have completed have given a "Computation error".

I had seen computation errors on CPDN previously, before I had installed all the correct libraries etc, but they usually happened at a run time of 0:00:00 (or very close to it). Now the tasks are running for a reasonable amount of time of around 40,000 seconds, and then they only give "Computation error" at the end of that time.

...Hmm that's interesting. I just looked at an example of a work unit for which I had had a "Computation error", and it looks like all of its tasks have had errors on a variety of computers with different operating systems.

These problems are talked about in 2 threads in number crunching:

HadCM3 short - errors galore

hadcm3n Full Res Ocean out of memory error

Out of memory is "stack memory".
These matters are being looked at by the project people.

OK thanks.

I think my best course of action is to let it continue running and see what happens.

In theory, the 32GB of RAM that I have should easily be enough.

Just out of interest: Would CPDN (or indeed BOINC) benefit in any way if I installed more?

"stack memory" is a small area of ram that's used by the processor for temporary storage of variable data. I think that the size is OS dependent. Also, it's only a few megs. Or used to be.

BOINC doesn't do much, or need much memory. It's sort of a combination "information desk" and "traffic controller".

Climate models are "reasonably" happy with 1 gig of ram each.

(Historical note:
Years ago, one of the UK universities was working on a high-res climate model that would need about 4.5 Gigs of ram per model. Unfortunately we lost our contact person before it got far, so I don't know what happened with it.
But it would have been interesting.)

OK thanks Les.

My other BOINC projects seem to be working OK (ie. running and then uploading results successfully) since the changes that I made, so I'll just leave it to run. Hopefully CPDN will also come good.

A couple of completed tasks are showing now. Hopefully we're back on track. I'll mark this one 'answered'.