I was reading through the BOINC wiki earlier. If I understand correctly you can create a cc_config.xml file and use the <data_dir> tag to specify a custom path without reinstalling?

Unfortunately not. BOINC would need to know the location of the data directory, in order to read the cc_config.xml file, in order to....

Er. I don't know why that's still there. Possibly a left-over from when cc_config.xml lived in the same directory as the executable programs? But that wouldn't be possible on modern versions of Windows, at least.

I don't understand why tasks running in high priority would disable GPU processing. Does it change something with the process' priority in the OS as well as in BOINC? I'm not seeing how/why high priority would take away the 0.1 CPUs that most GPU tasks use.

It is how you add the cores up and what the project requests for cores. It gets complicated, but essentially it works out to this, you have say 8 cores and 8 jobs in EDF. Where is BOINC going to get the 0.1 core to run the GPU task? If you have 8 cores and 6 tasks in EDF mode, BOINC will run one more CPU task and the GPU. Well, that is what it is supposed to do, however that isn't what happens always. If all the tasks are 1 core tasks, BOINC will over commit and run 8 + the GPU. But if you have one 8 core task it will not over commit and the GPU task won't run, EDF mode or not.

So depending on your project mix and what goes into EDF it can shut down the GPU. So if you run a project mix with multiple core jobs to get the best throughput you need to tell BOINC you have just slightly less than an integer number of cores say by letting it use 99% of the cores not 100%. Seems counter intuitive, but the GPU is so much faster than the CPU, sacrificing part of the CPU is nothing compared to keeping the GPU going all the time.

I'm probably misunderstanding, but why do GPU tasks always use some CPU? And it's always a fraction, like 0.5 for Collatz or 0.01 for Asteroids. How do you get half a thread to run on a processor? :-P I guess what I'm trying to figure out is, does the CPU actually do anything, or is it just the "middle man" for the GPU?

In order:
1) Data has to be moved from disc to main memory to the GPU memory and back.
2) Depends on the science.
3) You have it spend time sleeping. It isn't really a thread count at that point, more an expectation of how much sleeping it will be doing.
4) Yes.

The last one is really yes. It has to be a middle man. It also has to do a small amount of work getting the data in order to be sent back. However for some science things, there is a lot more than some minimal housekeeping that needs to be done. Those may need things split or combined in some special way for the GPU to chew on them. At points in the life of a work unit all the work may be being done on the CPU and at other points all on the GPU. Oh as to that fraction number, it isn't fixed, Seti for one issues work units with different fractions based on the data in the unit.

Something like this: Blacklisting hosts

I would suggest trying it first on your own host to see how scary error message it sends to volunteers.

Collatz appears to be down with the following message on its website: "The project's database server is down. Please check back in a few hours"

I think the max additional is actually 0.25 rather than 0.5. BOINC is notorious for getting task estimates completely off: generally, over time BOINC should start to give more accurate predictions for your computer. The max additional tasks can be reduced in the Advanced view > Computing preferences > network usage. If you are always connected to the internet then you should probably use very low values here: I actually use 0.00 for both.

What is it with project admins? Why do they never check their message boards?

The recent torrent of spam has rendered a couple of projects boards unusable. Some project's 'report post' facility doesn't work, other projects it's clearly being ignored.

Perhaps these are just zombie projects - The admins are slumped, lifeless, over flickering CRT monitors, festooned in cobwebs, while rats chew at their decaying flesh. Meanwhile the work generators churn out tasks for hungry crunchers who blissfully believe that their work is useful and valued ...

Admins: Sort. it. Out.

Cheers,

Al.