LHC@home

Hey! I stumbled across an article I read in the paper a couple of months ago featuring Einstein@home. It was cool because it talked about something I've always been fascinated with. Grid computing. I first heard about it when Gateway stores where leaving their computers on at night and link them all together. So when I followed the link(s) to Einstein@home on the internet, I ran into BOINC and grid computing I was hooked.

So because I'm a major physics nut, LHC@home was the place to be. So. What I'd like to know is how to set up or tweak the computing preferences to get the most bang for my buck.

Probably the most pertinent info is; Leave tasks in memory while suspended? yes. Switch between tasks every: 60 minutes. On multiprocessors use at most: 8 processors. On multiprocessors use at most: 100% of the processors. Use at most: 66% of CPU time. Running a Intel Core i7 930@280 GHz. Disk: use at most: 200 GB. Leave free at least: 5 GB. Disk: use at most: 100% of total. Currently 80% free space. Running an Intel SSD SC2BP 240 G. I can get a bigger drive if you like. Yum. Swap space: 95% of total. Memory when computer is in use: 100%. Memory when computer not in use: 100%. 18 GB of memory. Running Windows 7 Professional. Any suggestions? Thanks. Greenman

---

"Use at most: 66% of CPU time" only if you have heat issues. You can increase it if you wish.

The HDD has plenty of space, even ClimatePrediction would be happy there.


There is one setting that I usually increase : "Tasks checkpoint to disk at most every (default=60) seconds". A reliable system should not need that many checkpoints, checkpointing interrupts the calculation and slows down the crunching. My current setting is 10 minutes (600 seconds) but I already ran 3600 seconds without problems.

If it later shows that your tasks tend to throw heartbeat errors, you can still decrease the checkpoint period. Heartbeat problems depend very much on the projects (and other programs) that you run concurrent to LHC. If you run LHC and Einstein, the heartbeat watchdog should hardly ever interrupt your results.

The only thing the higher setting would interfer with would be if you had "Leave tasks in memory while suspended? NO" but as you have "YES" there, this does not apply to you.

In some projects (not sure for LHC@Home) there is a big difference in performance between Windows and Linux (probably related to the different compilers and libraries used). Maybe you can give a try to some Linux distro and compare it to Windows. I know projects for which Linux is faster than Windows and also projects for which Windows is faster than Linux. Also, I found different results for my computer in Whestone benchmark using different distros (1.1 GFLOPS for Mint and 1.5 GFLOPS for Debian).

Leave tasks in memory while suspended: I think it's only useful for buggy projects that crash if you pause them.

For the rest, it depend more on what you do on your pc besides BOINC.
With Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz & Windows XP SP3, I use at most 75% of processors (3/4) and at most 50% of cpu time, and I still put a good fight against other people regarding working time and cpu time (though I don't follow hardware evolution, so I don't know if they indeed have more recent hardware)

Where do I check for heart beat errors?

---

Leave tasks in memory while suspended: I think it's only useful for buggy projects that crash if you pause them.

For the rest, it depend more on what you do on your pc besides BOINC.
With Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz & Windows XP SP3, I use at most 75% of processors (3/4) and at most 50% of cpu time, and I still put a good fight against other people regarding working time and cpu time (though I don't follow hardware evolution, so I don't know if they indeed have more recent hardware)

Your suggestion may be fine if you only run BOINC tasks but if you are doing "real work" with your system you may not want to be sacrificing memory while you are doing some Photoshop, Illustrator, Framemaker, etc task.

I have generally had no problems allowing BOINC to dump a Task out of memory when doing other work. It seems to work quite well and I just set those applications that I want to have run without BOINC eating up CPU and Memory into the "exclusive application" tab under Preferences.

I'm not sure if this setting has any effect if you are running Tasks under the Oracle VM as T4T does. At one time it didn't because BOINC didn't control VM but now it might since BOINC Suspends VM quite nicely.