Collatz Conjecture

[vaughan]

This project's estimated task run time is interesting. For example, my Intel Q8200 @ 2.33GHz running Win 7 64bit downloaded two tasks. One says 57 minutes the next says 47 hrs 47 minutes? The 57 minute task is being crunched by the GPU, the other task by the CPU.

Conclusion: the GPU is 50x more efficient at crunching the Collatz tasks.

[liuqyn]

I received this e-mail from the admin,

Credit on the CPU apps is slightly above average vs. the BOINC standard. That being said, while the CPU apps work well, due to the ability to run 16 -800 iterations in parallel on an nVidia CUDA or ATI CAL/Brook GPUS vs. a CPU far outweighs the processing power of a CPU on this project, so machines with CUDA and RC600+ ATI machines will get far more credit per hour.



As did the original 3x+1 app , the CPU apps currently uses the GNU GMP library on the CPU apps whereas the GPU apps use a 240 bit library. At some point, the will cease to return valid results whereas the CPU apps will continue to work. So, while the GPU apps are limited to 2^240 bites, the CPU is virtually unlimited.



In other words, for now, the CUDA and ATI cards will do much, much better on this project than the CPU only versions, even with the CPU SSE or SSE2 optimized apps. Then again, the GPU apps require much more electricity. Got any suggestions as to what to tell my wife why our electric bill is almost double that of last year while we have the same number of computers? J



Jon Sonntag

[Beerknurd]

I aborted them... I ain't waiting 50 hours...

[AMDave]

LOL.
He should tell her to stop using the hairdryer.

I aborted my CPU wu as well.
Waiting for the Linux-CUDA client (I hope they are working on that)

[AMDave]

Hey, Beerknurd

don't forget to set your project settings to "Use CPU = N"
otherwise when you connect again it will download CPU work units again.
I'm going to try an old ATI card on the win machine later (when I can get my son to take a break from WoW & battlenet )

[Nflight]

I am going to wait one work unit out and see how long it takes! I know I am crazy but I don't have a compatible video card at this time...

Estimated time is 102 hours on my system. I will tell you when it is complete on Monday!

[liuqyn]

CPU tasks are much faster now (64bit windows anyway), running 2-3 hours on average.

[Beerknurd]

How are the credits??

[liuqyn]

one of my 940's is running them about 7000 seconds and getting about 160 credit. so right around 82/hour. or 8k per day. not including whats running on it's GTX285 which is about 1500 seconds(wall time) for the same 160ish credit. which should nab it another 9k per day.

so, CPU credits are good right now, but cuda creds are on the low side.

[liuqyn]

not sure what the ATI cards are running right now, have to wait til I get home to set them up.