Hi guys, it's me again with more questions.
I have set my i920 to use only 6 cores and when running Einstein@Home, 6 WU are dealt with at the same time with a total CPU use of 75%. It takes around 6 hours and then 6 jobs are done.

Now with GPUGRID and the use of CUDA, only one WU can run at one time with my GTX285 graphics card. CPU load is 5%. So 95% of CPU has nothing to do when the pc is idle (when I sleep or are at work). It takes around 2 hours of CPU time (give by BOINC Manager) but will take also around 6 hours in real time (between start and finish). So in my opinion this is not efficient.

Another thing I noticed is that the graphics card becomes very warm. A car thermometer hanging for the outflow of the cards fan is showing 40-43 degrees Celsius. When touching the card (back on the pc beneath the dvi-connectors) it feels very hot I cannot touch it very long. This concerns me as I am afraid for the lifetime of the card. With the current software of nVidia I cannot find its core temperature.

So all in all can someone explain why CUDA is better to do WU’s crunching than with CPU cores?
The only thing I can think of is that it keeps the CPU free for doing other tasks. But the heat of the card I do not like at all, moreover it becomes very warm in the room during summer.

As always thanks for the input.

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Greetings from TJ

Now with GPUGRID and the use of CUDA, only one WU can run at one time with my GTX285 graphics card.

CPU load is 5%. So 95% of CPU has nothing to do when the pc is idle (when I sleep or are at work)

. It takes around 2 hours of CPU time (give by BOINC Manager)

but will take also around 6 hours in real time (between start and finish). So in my opinion this is not efficient.

Another thing I noticed is that the graphics card becomes very warm. A car thermometer hanging for the outflow of the cards fan is showing 40-43 degrees Celsius.

it feels very hot I cannot touch it very long. This concerns me as I am afraid for the lifetime of the card. With the current software of nVidia I cannot find its core temperature.

So all in all can someone explain why CUDA is better to do WU’s crunching than with CPU cores?

moreover it becomes very warm in the room during summer.

As always thanks for the input.

@Hydropower: Thanks for your answers, this helps me a lot. I have a window open and running a fan during daytime. My computers are at the attic with only one window that can open. It is in full sun light almost all day. And as you know it is quit warm in the Netherlands currently and becomes even warmer inland as the week goes by.

The machine with the GTX 285 card is new and not my own, so I must be a bit calm with it and I really don’t want to overheat it.

@ETA: Thanks for your input as well. I’ll leave 6 cores on, they are running Einstein and I need the rest for other programs.

And regarding your thoughts on efficiency: you're really comparing strawberries and oranges here. If you can eat a strawberry in 2 minutes and the other guy can eat an orange in 6 minutes, who's more efficient?

For that application X seti@home has a cuda and CPU version of Multibeam app.
It is 12x faster to run the cuda app over stock.
However it is a poor comparison as the CUDA app is poorly optimised.

GPU's are theoretically 50-100x faster than a CPU
In practicality its more like 30-50x faster
Which is a huge speed increase (1 gpu = 30-50 cpu cores)
Bob

Hi ETA and others, thanks for all the answers and input. It is now CUDA for me.

Yes I did, I sometimes still do it at night when I am sleeping. Running with 8 cores Einstein does not bother the RAM, it uses approx 27% of it. But using 8 cores to crunch and at the same time rendering something with mathcad is slow. Or when let it render in the background and use mathlab for something else simultaneously. Therefore I use a max. of 6 cores.

Now you gave a good example of the use of the GPU just as Bob did in Message 10934. I will do some Milkyway to see after the weekend when it becomes cooler. I don’t want to nag over the heat again but the pc is a month old and was a bit expansive, so I am a bid careful with the graphics card. I have read somewhere that the core temperature of the GPU from a GTX285 may go to 190 degrees Celsius! Than should the 40-45 degrees on the outside of the case be no problem at all, but yes it’s me, a bit scary for heat at electrical devices.

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Greetings from TJ

Then I have a problem I think ETA. I have installed “throttle” from the BOINC ad-on page and that shows a GPU core temperature of 64°C and then is the card not doing else than showing a background on two screens and these Internet-pages.

I will run GGPUGRID again after the weekend when it becomes cooler, and will see what happens.

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Greetings from TJ

I looked for GPU-Z and found it at different sites, but all with a warning from McAfee. While they all mentioned that there is no virus or so, I will not download it, as my i7 is my work pc and I will absolutely have no problems or trouble with it.

I have installed TThrottle from efmer.eu (it is listed at BOINC add-ons) and that is showing all temperatures and options to set these temperatures. This works fine for me (since a few days, I am still testing it).
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Greetings from TJ