Feature Request: Throttle Button

PeanutMocha · June 10, 2011, 02:16:59 AM

Currently in the Render View, I can pause rendering or let it run full speed. It would be nice to have a "Throttle" button that would reduce the number of threads to a level that does not saturate all available CPU's (maybe leave 25% of CPU capacity free for other tasks).

Use Case: During the day I work on my PC while also rendering "in the background". Sometimes TG2 gets so many CPU cycles that other applications don't respond for several seconds (per keystroke). While I can pause rendering to work, it would be nice to easily just free up enough CPU to do light work.

Tangled-Universe · June 10, 2011, 02:48:29 AM

The easiest way for this is to set the maximum threads in the renderer to the amount of cores you have, minus one.
So in case you have quadcore, then set max threads to 3, leaving 25% CPU resources to other tasks. Works like a charm for me.
A throttle function with dynamic threading and such is likely not feasible I suppose.

Henry Blewer · June 10, 2011, 03:07:19 AM

You can also use the Windows task manager to reduce the task priority. I do this when I want to leave something run, but want/need to do something else. I have found that changing the priority to below normal or even low does not slow the render down too much with Windows 7. Windows XP was not so good at this.

PeanutMocha · June 10, 2011, 02:09:32 PM

That's good to hear that setting the task priority a bit lower works well in Windows 7. I noted too that it never worked well in XP. Setting number of threads to (Cores-1) does not fully leverage the CPU when I step away.

Perhaps the feature request then is to configure the default task priority for the renderer along with other threading options. That can be done in Windows and I assume on OS X as well (since at least Linux supports that concept, I guess OS X does too).

Tangled-Universe · June 10, 2011, 04:18:50 PM

I see no reason to do that, honestly. Why adding function inside software which the OS offers already? To me that would be clutter.

Oshyan · June 10, 2011, 06:14:41 PM

I agree, this is covered by the OS already, in a way we couldn't really improve on. Setting application priority is something I do all the time and it works extremely well.

- Oshyan

Henry Blewer · June 10, 2011, 06:19:09 PM

You can also set the core affinity in the task manager.

Matt · June 10, 2011, 10:06:10 PM

I can see the use in being able to change the number of threads on the fly. It's something we could do if we want to. I don't know if changing the task priority gives you the same responsiveness but it means you don't have to remember to set threads back to maximum when you leave the computer.

On my i7 (4 real cores, 8 if you count hyperthreading) I usually have the number of cores set to 7 in the prefs. Leaving one "hyperthread" unused (roughly speaking) keeps the computer responsive but doesn't affect render times very much.

Oshyan · June 10, 2011, 10:31:45 PM

Lowering the priority does a great job of allowing you to use the system when desired, then throttling up to faster rendering when you stop using it, without any need for further setting changes. There are 3rd party tools that can auto-set the priority of any app you start or that gets loaded, for example Process Tamer.

- Oshyan

jaf · June 10, 2011, 11:54:37 PM

I've been using a program called "Process Lasso" ( http://www.bitsum.com/prolasso.php ). They have free versions. I got the Pro version free through Giveaway of the Day and have been evaluating it.

It seems to work pretty good, though it's hard to tell. I know from past experience, when I get impatient and "start clicking stuff" it usually winds up as "reboot time." But this utility seems to throttle back my "enthusiasm".

Henry Blewer · June 11, 2011, 08:35:51 AM

I also use IObits GameBooster. It does a good job clearing out the extraneous threads and processes I normally run. It speeds up the renders on my machine. (Not so many CPU cycles being sucked up by things like Media Player...)