Really strange results. The credits aren't even close to proportional to the time spent on the wus.

In the last 2 days, I've seen the following, all on the same box with the same cards:

# Time per step: 44.911 ms
# Approximate elapsed time for entire WU: 22455.469 s

Granted Credit: 1887.96527777778

-------------------------------------------------

# Time per step: 34.907 ms
# Approximate elapsed time for entire WU: 17453.613 s
called boinc_finish


granted credit 2435.94444444444

-------------------------------------------------


# Time per step: 27.683 ms
# Approximate elapsed time for entire WU: 23530.125 s

granted credit: 3232.06365740741
____________

I have seen the same at my WU's. Maybe new credit regulations??
____________

How are they granted?? Before for me it looked always as you get the same credit (3,232.06) for each WU.

I don't see how they are granted when i look to my last WU's.

Time per step: 56.057 ms
Approximate elapsed time for entire WU: 28028.304 s
CPU-time: 15,081.44 s
Granted credit: 1,887.97

Time per step: 33.296 ms
Approximate elapsed time for entire WU: 16648.047 s
CPU-time: 12,795.25 s
Granted credit: 2,435.94

Time per step: 45.582 ms
Approximate elapsed time for entire WU: 38744.812 s
CPU-time: 23,842.38 s
Granted credit: 3,232.06
____________

There are at minimum 3 different type of WUs. Look at the run time, it's also different. Your PCs are hidden, so I can' look at your run time for the CPU. Otherwise I would calculate the runtime from the value of

# Approximate elapsed time for entire WU: 18088.121 s

in your task data. This WU from my GTX260 was running 18088.121 seconds and I got 2435.94 credits for it.

2435.94 / 18088.121 * 3600 = 484.81 cr/h.

Thid is the way to compare the WU, not by compare the credits directly.
____________

I have also been discussing this in another thread (Curious Performance Difference) under Number crunching. Don't know if PS3's have the same problem or if it's just Nvidia cards but my lower granted credits started on the 10th of Dec and about the same time all these DCF and no cell processor/no work problems started.

Kokomiko: If I calculate my credit for two very different WU I get these answers,

Task 127339 - 2435.94 / 5822.16 * 3600 = 1506.20 cr/h (GTX280)

Task 126687 - 2435.94 / 23082.91 * 3600 = 379.9 cr/h (8800GT)

GDF has explained that the credit issued is fixed therefore no matter what time it takes you should still be awarded 3232.06 for the WU.

Just another problem to fix. Good luck GDF

GDF: Maybe should confine this problem to one thread before it gets out of hand?

Cheers

Pat

Task 127339 - 2435.94 / 5822.16 * 3600 = 1506.20 cr/h (GTX280)

Hey GDF,

I'd like to believe that but I have 2x280's and 2x8800GT's and I have compared CPU time to granted credit and even elapse WU time to granted credit and I just don't get it. How can a WU take 40102 sec and be granted 2435 credit and then a WU that takes 17497 sec be granted 1887 compared to another WU that takes 39580 sec and gets 3232. ALL are in elapsed time because I was told CPU time is not the way to judge. My 280's normally process a WU in 5-6hrs consistently, whereas my 8800GT's normally process a WU in 11-13hrs consistantly. I am still doing the same number of WU in a day but am getting less credit when technically if I have shorter WU I should be doing more WU's and getting the same RAC as before. Logically of course. Is there a limitation on the amount of WU issued to one system per day?

Pat

Is there a limitation on the amount of WU issued to one system per day?

Pat

Sweet!

Thanks

You can always learn something new every day!!

Pat

Can't say that I'm fond of this new credit method. It only started on the 11th of December. and in the last 70-80 WU's under half where full credit and my rigs still complete the same number of WU/day with less credit.

Pat

Could it be, that the entry

# Approximate elapsed time for entire WU: 18305.484 s

is no longer the real time for elapsed WU but rather the CPU time since the new application is running?
____________

Task 170388 - SM21632-SH2_USPME-1-40-SH2_USPME2020000_0 has a approximated time of 39646.065 s under the 6.55, task 170472 - hg19408-SH2_USPME-1-40-SH2_USPME1400000_0 18391.686 s under the 6.54. Both are running on the same box, no games while running and the same credits.
____________

That's what I've been saying. Nothing lines up for a definitive answer. After checking my GPUgrid project stats my RAC has dropped 4000-5000 points. This started around 11 Dec and that was about the time all these DCF and no work issues started.

I have a couple of weeks off so I'm going to try and find the correlation and determine what WU get what credit and for how long they take to get processed, unless someone knows already?

As well all of my WU's are processed with ACEMD 6.55 with 3+2, no gaming. It seems that even though WU's need 0.03 CPU's they tend to finish faster with one CPU for both of them.

Pat

"Nothing" is a bit too harsh. In my case and in Xaaks example the 3232 credit WUs and the 2436 ones do line up. It just the 1888-ones that are off in both cases.

Lets see in 24hrs or so!

Cheers

Pat

"Nothing" is a bit too harsh. In my case and in Xaaks example the 3232 credit WUs and the 2436 ones do line up. It just the 1888-ones that are off in both cases.

Ok, ok. Nothing was a bit too harsh, but here is what I have found. There are two kinds of WU's, 500 step ones and 850 step ones.

Any WU that has "GPUTEST" in the name will get full credit 3232.06. (850 steps)

Any WU that has "SH2_US_..." in the name will get 2435.94 credit. (500 steps)

Whilst any WU with "SH2_USPME_..." gets 1887.96 credit. (500 steps as well)

When I total my elapsed time for my 8800GT rig for one days worth of return, I find that my 2 GPU's were working 47.18549 hours, so just under 24hrs each.

When I total my 2 280's, I get 27.95813 hours. Just over thirteen hours a piece, which would explain the 4000-5000 RAC drop.

My 8800GT's with client 6.4.5 seems to be working ok (knock on wood) and more efficiently that my 280 rig which is running client 6.5.0 and need consistent updating.

I will post anythink new if it jumps out at me.

Pat

Just a correction in my math: millesecond verses second.

Those would now be 500,000 step WU and 850,000 step WU.

Doh!!

Pat

This should not be the case. If it is there is an mistake.
The credit system has not changed it is just that now we have several different molecular structures on going with more or less atoms, for more or less iterations.

It should produce approximately the same credit/day irrespective of the type of WU on the same PC.

gdf

Same here. Please discontinue the work units that send out 1888 credits, unless there is a fix for it. These work units take as long as the 24xx units or longer and give less credit! All (3) machines are Windows, 1 64 bit Vista &3 32 bit XP. All 3 boxes reflect the same reults. 1 machine has a 260 GTX 192 (Win XP 32 bit), 1 machine (2) 260 GTX 216 (Win XP 32 bit), & 1 machine (2) 280 GTX Vista 64 bit ( User ID 9485). Thanks for all of your hard work to make this happen!!!

Hi,

were any changes introduced to the 500k steps workunit which give 1888 credits?

I finished my third one of this kind this morning and it definitely had a shorter running time than the first two. The time per step is now in the same range as with the 500k steps / 2436 cr. units and 850k steps / 3232 cr. units.

Here are those three workunits with 1888 credits:

resultid=168029
resultid=168037
resultid=175524

The only major change on my side is a version change from BM 6.4.5 back to 6.3.21 (due to the silly behaviour of the resource scheduling for cpu-bound tasks with 6.4.5). If nothing was changed with the workunits, could this be the reason?

Regards
Alex

I have also some with same runtime but credits are lower now?!

Change in credits? New acemd WUs taking longer than before and receiving 2932 credits instead of 3232. New credit policy?

Change in credits? New acemd WUs taking longer than before and receiving 2932 credits instead of 3232. New credit policy?

The new workunits use a more advanced algorithm for handling the electrostatic called PME. This new algorithm is very important for us.
However, as it is more complicated and uses libraries like cufft, the number of flops are only approximated because it is difficult to estimate them exactly. We are currently trying to work out a better estimate for the flops and further optimize the application.

There should be new apps out in the first 10 days of January.

GDF

One kind of WU, one level of granted credit. No matter what the WU is supposed to do. If it is a more advanced algorithm, then why are the credits lower? "It's based on FLOPS!" That great. I have seen no proof of that. It seem to be based on the number of steps in a WU. All WU's were 850k step WU's before Dec 10th and all got 3232.06 credit. Now we have 4 different WU's with all different credit, and don't reflect the lenght of time it actually took to process a WU. There is no reason that there cannot be 1 type of WU based on the 8800GT efficiency and leave it at that.

"For bigger systems we increase the iterations". That's funny because 7 out of the last 13 WU's done on this host: 16824 were the smallest WU. Not very efficient when those small 1887 WU take almost the same amount of time as the 2435 WU.

The time estimate is a hit and miss. All WU that have JAN2 in the title actually reflect the proper duration. (i.e. 5-6 hrs on a GTX280 and 11-12 hrs on a 8800GT) The previous WU never showed the proper duration just the proper elapsed time on the GPU. So I'm looking for more of the JAN2 WU's.

Pat

Our WUs are all supposed to require approximately half day on a 8800GT (114 shaders), around 6 hours for a 280GTX. For a bigger system, we reduce the number of iterations to meet this target or we increase it for bigger systems. This is not exact of course, allow for up to 50% error.

Something more, the time estimate of the boinc client is usually wrong, but the progress bar is EXACT. It's the application to tell the client how much it completed. You can do very accurate estimates from that.

gdf

Well, until there is some kind of perportionality to the credit granting scheme, I'm only going to run this project when I can't get work from others.

I had another case yesterday where 3 units that took ~19000 second got granted 1887, and one wu that ran for ~17,500 seconds got 2424. The 3232 credit wus were running ~22000.

Later guys.

I've seen fairly constant run times on my box.

MrS