x38g reports

[Jason G]

Here's one that is interesting. Must say they tried their best to prove me wrong but finally gave up and gave me credit.  http://setiathome.berkeley.edu/workunit.php?wuid=783092275

  You're also canonical, not that surprisingly with all those apps erroring out.

Jason

[Terror Australis]

Using 275.33/38g & 39f I have a downclocking problem with one particular card. There is no problem using 191.07/6.09.

It's one of 2 EVGA GTX285 FTW's in the same box, the other card behaves itself perfectly. I have confirmed it's the card by swapping cards between the sockets.

Jason. As there are two identical cards, one which plays up and one which doesn't. Are there any tests you would would like me to run on the cards to help track down the reason for the downclocking issue in general ?

T.A.

[Jason G]

One thing that has become apparent lately, is that some of the optimised code may be pushing harder than some OC scanning tools.  It is the 560tis that came under scrutiny first  for being close to the edge from factory, and seems to have some per manufacturer &/or per Silicon differences.   

As a result of the ongoing examination, I may need to take some of the 'hottest' running Cuda kernels, and make some more targeted scanning tool out of it. In the meantime I suggest see what happens if you back the suspect card right down to reference clocks.  If that still doesn't help there could be further issues.

If it turns out I am pushing harder that whatever the factories use to bin parts for factory OC models, then I may have to look at some sortof backoff throttle.

Jason

[Terror Australis]

On clser examination there is a possibility it's related either to certain WU's or series of WU's.

THE FTW cards are factory OC'ed to 725MHz, I have backed them off to 715MHz and it still drops to half speed with the same degree of randomness.

Two WU's in question are here and here

T.A.

[Jason G]

Two WU's in question are here and here

Thanks, no indication of a cause in those, so we'll keep looking.

What are the temps like going at flat chat?

It's stability of my code (exhibiting apparent task dependency)  versus Factory OC's that are in question, i.e. Higher stock than nVidia reference.

nVidia reference clocks for GTX 285 are:
Core: 648 MHz
Shader: 1476 MHz
Mem: 1242 MHz

Still crook at those ?

[Jason G]

There are some further clues in your errored task list that I'm looking at, tracing some code. Back later with some beer to fuel a further analysis.

There's still quite a few things to eliminate from suspicion, but we'll isolate what's going on eventually.

Jason

[Terror Australis]

Hi Jason - Here and here are a couple more units for your perusal. For comparison THIS is a "good" unit from the same card

In a short run of about 12 hours, reducing the card to 648MHz showed no downclocking errors (it was dropping to approx half speed before). I've put it back up to 702MHz which GPUZ claims is the "stock" speed and will report back tomorrow (The 70 Meg downclock from the EVGA factory spec was just too irritating to handle :-)

T.A.

[Jason G]

Thanks,
  It gives me some ammunition to approach things properly with the new 560ti in the other room, which I have yet to put under any crunching or test pieces. I intend to use it to help isolate what's going on, attempting to replicate what some others see .

If I'm pushing some code portions 'too hard' (that is harder than what the factories are using to determine stable OC or bin parts), I'll just have to back those off, making them optional via advanced user settings somehow. (There could be a lot of them, so probably some sortof configuration file would be needed, along with stress tests to determine viable settings), as well as potentially some monitoring & failsafes.

It's likely to end up being a complicated tradeoff, whether to run faster code at a reduced clock rate, or slower code at potentially unstable factory settings, but the most stable config would have to be the default. 

Jason

[perryjay]

Got an error http://setiathome.berkeley.edu/workunit.php?wuid=801331122  Found a triplet thrice. Sounds like a song title or something.    My original wingman hasn't got to it yet and the new work hasn't gone out yet so I don't know if it was something I did wrong or not. Since it's the first one of those I've seen in awhile I doubt it's me.

[Jason G]

LoL.  It looks like he's running stock, so will find it twice before exploding (assuming your result was all in order).  It's probably just an extraterrestrial intergalactic cruiseliner sending an SOS distress beacon in morse code.  we don't want those anyway, we're looking for extraterrestrial intelligence, not shuffleboarders.

[perryjay]

Got it, no shuffleboarders.  If I got it thrice does that mean all my wingman will get is  S, O ?

[Jason G]

Got it, no shuffleboarders.  If I got it thrice does that mean all my wingman will get is  S, O ?

LoL, probably more like the S plus the first 'dah' of the O  , since 4 tones would make 2 triplet detections already if you think about it, 5 tones could make [Edit: 3 triplets].  Won't be long until I remove this limit anyway.

[Richard Haselgrove]

It's probably just an extraterrestrial intergalactic cruiseliner sending an SOS distress beacon in morse code.  we don't want those anyway, we're looking for extraterrestrial intelligence, not shuffleboarders.

Nah, the cruiseliners look like 2035680302 - overflow on 23 gaussians after 75 minutes. It's the wake, you know.

[Pepi]

What stupid credits
2.66 credits for 1200 seconds of work

http://setiathome.berkeley.edu/workunit.php?wuid=799356547

[Jason G]

Oh there's more fun to come yet