What is the deal with folding and how it uses CPU power

[Chrispy]

Ok I have a 2.0GHz PM G5 that gives off an aweful high pitch sound when running games (UT 2003 and WoW). The system is quite as a mouse the rest of the time but loud in games. Now, I ran folding@home using the InCrease pluggin and setting a protien to run on CPU 2. I have a few questions...

If the app is taxing CPU 2 then why does CPU 1's temp go up too. The procs used to run at 136 and 134 and now they run at 158 and 155 with folding. Is this bad? Will this shorten the life of the computer by doing this?

Second, does folding know to back off the CPU if it needs to be utilized for something else? I did a flyby benchmark in UT 2003 and got the following results..

30.887060 / 83.967232 / 249.375061 fps -- Score = 73.866318 w/folding on

33.947971 / 84.106590 / 225.305328 fps -- Score = 74.008659 w/ folding off

As you can see, it made bascially no noticable difference in the game performance and made the computer shutup haha. If a game was to use the second CPU from time to time as WoW sometimes does for sound will folding hurt me? Any information on this would be great. Thanks!

 

[MrCommunistGen]

Folding is designed to be the lowest priority task running. If another task demands CPU time it gets it... however, the transition is not COMPLETELY instant although its darn close, and also when OSX assigns processor time to multiple apps this uses some processor time... this probably accounts for the slight discrepency.

As for the temps... I it could be that since the processors are adjacent to each other that even though only one is being used both are getting warm. More likely however is that both processors are actually running... (don't quote me on that its just a guess)

As for temps being bad for your computer... yes and no. Yes: as a general rule substances degrade faster at higher temperatures. For most substances an increase of 10C will double the reaction rate... at least at room temperatures... which the 150's F obviously is NOT. However, the processors' are probably designed to run at up to 80C (which is about how hot average x86 processors are designed to run) which corresponds to 176F so you shoud be OK in that area... however once again don't quote me on that one... its your computer... I suggest waiting to see if anyone else can pull up the thermal design for the G5 processor before you decide on this one though...

-mcg

 

[MrCommunistGen]

Update

After re-reading your post I have come up with another theory as to why both processors are heating up... the plugin you mentioned "InCrease" which I was unable to find any info on after a quick search COULD be a pluggin to allow folding to use 2 CPU's instead of just 1... making it dual processor capable. After thinking about the plugin's name for a second this seems to make sense... letting folding use 2 CPU's instead of 1 would "InCrease" performance...

What you should do is go to the Activity Monitor app in Utilities and see what your CPU load is. I'm hoping a dual CPU system will show the separate loads of each cpu (I don't know... I've got an old iMac). If it doesn't then if it shows more than 50% utilization for the fah5 core then for InCrease does in fact allow use of both cpu's

just my 2¢
-mcg

P.S. InCrease seems to be a play on words too... when you fold something you crease it... haha Its brilliant!

 

[Chrispy]

Thanks for the reply InCrease was, indeed, designed to let you use both CPUs to do the folding. However, I have set only CPU2 to be doing any of the work so CPU 1 should be free. I will open just the terminal and see what happens then. Keep the comments coming all and thanks in advance for the help.

 

[daveL]

The single Folding process is migrating back and forth between the 2 CPUs. Whenever a CPU has nothing else to do, it runs the Folding process, so it runs on whatever (but only one) CPU is idle. In reality, you are running Folding 50% of the time on CPU "A" and 50% of the time on CPU "B", more or less.

 

[Chrispy]

The single Folding process is migrating back and forth between the 2 CPUs. Whenever a CPU has nothing else to do, it runs the Folding process, so it runs on whatever (but only one) CPU is idle. In reality, you are running Folding 50% of the time on CPU "A" and 50% of the time on CPU "B", more or less.

Hey Dave, funny you should say that I was JUST about to ask that question! I decided to just fire up the basic termainal of folding to see if I saw a difference in temps and I noticed that CPU 2 ran cooler and CPU 1 was about the same. Then I ran the UT 2003 timedemo and got the same results as if I was not folding at all (but with no high pitch sound YAY!). So I guess the process just moves over to CPU 2 when CPU 1 has anything to do from what you say and what it seems the G5 is doing.

 

[MrCommunistGen]

The single Folding process is migrating back and forth between the 2 CPUs. Whenever a CPU has nothing else to do, it runs the Folding process, so it runs on whatever (but only one) CPU is idle. In reality, you are running Folding 50% of the time on CPU "A" and 50% of the time on CPU "B", more or less.

Ahh yes, this was another of my theories, I just didnt get around to typing it out. It also could be capped at using 50% of each CPU all the time...

-mcg

 

[wdlove]

I have a dual G4, just installed the the folding software for both processors. I'm not using InCrease. My Mac runs 24/7. Since the folding backs off when power is needed, wanted to fold at the maximum. No problems incurred.