Dual-core folding :)

[freakitchen]

Hi folks,

Just dropped a 4400+ X2 and 2GB of RAM into my main system (little present to myself!).

Already followed these instructions from Kov-Ice to get the two clients set up to fold simultaneously:

Originally Posted by Kov-Ice 1. Configure your first client. If you're running text-only console right now, you need to add a flag to the target line. Right-click on the short-cut, click Properties, and in the Target line, add a space and then "-config" (without the quotes). When you run it again, it will allow you to configure. In the Advanced Settings, be sure its Machine ID is set to one. 2. You can then remove the -config flag, but then add the flag "-local" to the end of the Target line. 3. Install a second copy of F@H in a separate directory. It will configure automatically the first time you run it. It must have Machine ID = 2. In its Target line, be sure to add the -local flag at the end.

When I run just the one instance, windows splits the process over the two cores, using 50% of each. The task manager, however, allows me to shunt the process over to one of the cores - using 100% of one, and none of the other.

I wondered which was the more efficient in terms of folding ability and less impact on system performance - or whether it makes any difference at all!

Cheers,

FK

[blue60007]

Running two clients on one core would be like running it on a single-core, I would think. Kinda defeats the purpose of running two instances since each would slow down half as much (only can use ~50% of that core as the other is taking that amount too)...overall output would be about the same as running one client by itself. Letting them run on their own cores would double output...

Keep in mind if it says a process is using 50% - it's using 50% of *total* CPU time, not 50% of one core. But rather 50% of two cores... ie, running a quad-core would probably show 25% usage if one core was maxed out (at least I would think).

[freakitchen]

Sorry blue, guess I didn't phrase my question very well - I never intended to run two clients on one core.

When I run a single client on my dual core, windows automatically splits the process 50:50 between the two cores - and so using 50% of the total processing power (at least that's what the task manager shows me).

I can also take that process, and shove it onto just one core - where it then uses 100% of the processing power of that core, and 0% of the other. (but still 50% overall).

My question was, which one of these ways (if any) is more efficient, and which would have the least impact on other running progs.

FK

[blue60007]

Oh! Ok, I see what you're saying....that's a really good question!

[Kov-Ice]

Hey FK. What do the percentages say when you're running both clients at once? Are you wanting to run only one client, or are you trying to keep both going at the same time?

What Bruce has to say in THIS thread at the folding forums may help with your question.

[freakitchen]

Thanks Kov-Ice, I think the thread you linked to answered my question - specifically that the 'set affinity' option (dictating which core a client runs on) has no effect over letting Windows manage it.

To answer your question, my aim is to run one client whenever my computer is on, and two clients when I'm away from the system for a while.

When I load one FAH process, the task manager shows CPU usage as split between the two cores - using around 50% of each and so working at maximum:

folding_1core.JPG

The way I understand it, though, I can have that process run entirely on 1 core, leaving the other core free. This in my mind uses the same amount of processing power:

folding_only1core.JPG

I just wondered which of these options was best in terms of least effect on other running programs and system performance.

For the record, here's what the task manager looks like when I run two instances of FAH - though I can't tell whether each is using its own core, or each is using 50% of both cores. Don't suppose it matters either way.

folding_2core.JPG

Cheers,

FK

[blue60007]

I'm running two instances on my 805 and I haven't noticed any performance differences...haven't changed affinity or anything. Of course, I haven't ran benchmarks to see if there is a 2% decrease or whatever, but it's not noticeable for me. HTH

[enhanced08]

I would think that it would be better to run 1 instance per core because i would think it would be quicker for the OS to look and see that "core 1" is at 100% so shift work to "core 2" rather than seeing that core 1 is 50% and core 2 is 50% so now split the work evenly between both core's. Even besides my odd way of looking at things, folding is designed to run on a single core so running it on 2 isn't going to help any and if I remember right it cant be run on more than 1 core, windows task manager displays the graph wrong, if I remember right that is.