In the case of these four tasks, two other machines produced matching results, while your result, although completed, did not match. As such, the tasks were declared invalid. Given that your machine appears to be a laptop, I think you are likely looking at a heat-related issue. Laptops are not designed to crunch over long periods without extra cooling options being applied (and even then are a risk for overheating).

SoB tasks are the most grueling tasks since the intensive LLR application is running for days. I would suggest that you switch to shorter tasks such as SGS or to other applications such as some of the shorter GFN work and (especially) the TRP or ESP sieves...the latter of these will run much cooler than LLR.

In addition to what Scott said, two of the four SoB results returned by your computer show clear signs of calculation errors caused by hardware malfunction. If it's not the heat, the next most likely culprit is the memory. If the computer has removable memory, I'd suggest cleaning the contacts on the RAM modules.

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My lucky number is 75898⁵²⁴²⁸⁸+1

The results aren't terribly exciting. At the end of the unit there's a residue value (like a checksum) which can be compared to check that two computers got the same result. If it doesn't match, then there was some error during computation.

I note from the computer results there were other invalid/inconclusive units so there is something not quite right. Personally I'd check the hardware. If you have, or can install some kind of monitoring software to see what temperatures are, as overheating can cause errors. Particularly if it is an older PC, check and clean it of internal dust around the cooler. Another possibility is bad ram or bad CPU. You can use tools like memtest86 or prime95 in stress test mode.

I'm currently dealing with some similar problems, but in my case it seems my high speed ram isn't quite stable at its rated speed on either of my compatible motherboards I've tried it on.

This computer is not a laptop. It is a stock desktop computer, an iMac. I think there is a problem on your end, or there is a difference in the way the Mac computes. I don't think there are any hardware problems.

Thanks,

67607*2^29561651+1 is not prime. Proth RES64: 1632BC1689CBEAAF Time : 2460097.899 sec.

67607*2^29561651+1 is not prime. Proth RES64: 1632BC1689CBEAAF Time : 1564490.589 sec.

Iter: 1729040/29561667, ERROR: ROUND OFF (0.5) > 0.4
Continuing from last save file.
67607*2^29561651+1 is not prime. Proth RES64: E59A553C67800827 Time : 2336038.227 sec.

I think there is a problem on your end...

There are many Mac users on the project, including developers. If there was a fundamental problem it likely would have been spotted by now especially on a long running project like this, unless it was really obscure. At a low level, Mac hardware isn't that different from PC hardware and can suffer from the same problems. The prime finding software here does push a system far harder than most normal tasks so significantly increases the chances of finding a problem that doesn't appear under low stress conditions.

It would not be a bad idea to test it rather than spend more time on what might be invalid results. Maybe try running the Prime95 stress test, which I believe is also available for Macs.

Edit: looks like Michael got there with a better answer quicker :)

To expand on one point Michael made, not only would I be very hesitant to crunch on a laptop, but I would be very hesitant to crunch on an iMac (he implied this, but I think it needs reinforcing). I do a lot of crunching on macs, but they are predominantly the old mac pro type, and have a pretty good ability to dissipate heat (They segregate cpus from pcie cards with separate areas and fans).

Not so in an iMac. If a quick google on "imac heat problems" doesn't convince you, I killed a 2011 17" MBP, with the same 6750M gpu. Nothing quite makes your heart sink like watching the screen go white as you realize something expensive just happened.

If you are intent on crunching on it, install something like istat so you can monitor temps and control fans. It is no fun watching your cpu temp climb to places it should never be. My old (2008) mac pros can stay at 100F/37C under full load. My newer (2009/2012) ones can stay under 150F/65C under full load, with some fan tweaking.

My MB Pro will run to over 220F/104C if you crunch on it, and running fans at full speed will get it down to 195F/90C. That will tend to kill things, the former rather quickly.

Expect to see that a lot. It gets validated when two results are returned from different users and matches. With the long units, it can take a long time to get that 2nd unit to complete validation.

Waiting for validation means you're waiting for someone else to finish that job. The validator runs every minute, so when your wingman (as we call him/her) comes in the actual maximum wait time for validation is 59 seconds.