Thanks. This is excellent and useful information. 

Skywise <into@oblivion.nothing.com> wrote:

After reading the existing posts I thought I'd chime in with
my experience. First, I am not a S@H expert even though next
month is my 10 year anniversary with the program.

I think I started a month later. Was 1999 the year it started?

Anyway, I have a working CUDA system.

What a struggle it has been to make this happen.
The two Asstropulse units that downloaded will finally finish tomorrow 
so I can take another stab at CUDA.

Hardware:
Core2Quad 3Ghz Q9650 CPU on Supermicro X38 based mobo w/4 gigs
EVGA Nvidia GeForce 9800 GTX+ with 512meg

What OS are you running? My understanding is that XP and Vista 32 bit 
can only utilize 3GB of RAM. I have a dual-core XP64 machine in addition 
to the XP32but it is AGP 8x and I'm not looking for a CUDA capable AGP 8x card.

I am running BOINC 6.6.2 which is a beta I downloaded some time
ago. Beta is up to 6.6.20 now. You can find them here:
http://boinc.berkeley.edu/download_all.php

This is a lot more complicated than they suggest.

Now, a word about the work units. CUDA WU's are different than
the other Seti WU's and different than Astropulse. CUDA WU's
only run on CUDA on the GPU, all other WU's run on the CPU.

Yes. Until I got into this, I thought they farmed out calculations,
sort of like a co-processor. Thilly me.

Early versions of CUDA _only_ ran the GPU (no CPU work) and it
took more trickery than I was willing to muster to get both
CUDA and CPU at the same time. However, 6.6.2 (and I imagine
later as well) can do both CUDA and CPU simultaneously. (talk
about cooling needs!!) I don't know about the current recommended
release.

After reading the forums, the existence of which I only learned about
during this escapade, I was quite confused as to which Boinc could do what.
Isn't there a 6.7 series also? It sounds like 6.6.whatever will do the trick.

Now, I do have to babysit the system a bit to keep it fed with
the right work units.

You will have to go into your seti settings in your BOINC
account online where you will find check boxes to permit or
deny which type of work units you want done.

I'm a bit confused as to whether this change is made locally in Boinc
or whether the change is implemented on the Seti end.

When I need more CUDA workunits I have to select that and
then update the project. It will then download some CUDA
work.

When I need more Seti workunits I deselect CUDA in my settings
and update the project. It will then download some regular
workunits.

I currently do not D/L astropulse even though my system chugs
through them pretty quick, in about 36 hours. (x4 as I have
four cores)

I'm puzzled by this. My 2.5 GHz dual-core AMD slogs through 2 workunits
in about 7 days. That would be 3.5 days per unit, but it still takes 7 days 
to get them done. Do you mean that your 3 GHz machine processes 4 Ap 
workunits in 36 x 4 = 144 hours, or will it actually chew through a workunit 
in 36 hours? I know Intel CPU's have large caches, but that's a five-fold 
increase.

I find my NVidia card with one GPU can burn through as many
CUDA workunits as all four cores of the CPU (or faster). So
I have to keep the number of CUDA vs CPU workunits balanced.

What a hassle. You'd think they'd CUDA-ize Astropulse since it drags
along so slowly. 

My biggest problem is keeping the beasty fed. I'm living in
the dark ages and still on dialup. I have to often leave the
system on overnight downloading workunits to keep this thing
loaded with enough workunits. I like to keep several days
of work on the machine for those inevitable server downtimes
when I can't get more work. Sometimes, by the time I am done
downloading 20 workunits, it's already finished 4 or 5!!

With what I spend on satellite, I could buy the best CPU. 
Nevertheless, if someone had told me 10 or 15 years ago
that I'd be able to buy a $100 thing on Ebay that could talk
to a satllite 30,000 miles away, I'd have said they were crazy.

The dialup issue is why I don't do astropulse. They take too
long to download one WU. I also seem to get less credits on
astropulse

I noticed that too. I didn't realize they were bigger. 
I suppose one could try to run Seti on the GPU and Astropulse on the 
CPU. It seems maybe that once Astropulse clogs up both CPU's, it won't
load Seti on the GPU.

Hope this helps.

Very much. Thank you. I'll try again tomorrow when the
Astropulse runs out.

Brian