how to raise base priority of gknot processes?

[thanhvn]

I'm using gknot 0.27 (with divx 5.02pro) and I noticed that gknot itself is running with base priority (in win xp) of normal but all processes called by gknot, such as besweet and virtual dub, during encoding run with base priority of low. Is there any way to change this because encoding at low priority takes 8-10 hours while encoding at normal priority takes only 2-3 hours?

[SKD_Tech]

Press CTRL+ALT+Delete

go to processes

Find the process you would like to bump up/down

right click on it

Scroll down to set priority

There ya go!

Also when you are encoding with VirtualDub on the status bar there is a menu to change the priority...

[thanhvn]

i already know how to change base priority manually (that's how i was able to tell what a big difference in time, 5-8 hrs, it made). what i am really after is how to do it "automatically". i don't want to sit in front of a computer waiting for gknot to spawn a new process and then manually change its base priority. (also, i noticed that if i manually change the base priority for say, vdub, the next time that process is relaunched by gknot, say, for a second movie, its base priority went back to low).

[thanhvn]

hmm, it's been several days and no response. i wonder if this problem only occurs to me or nobody bothered to find out why their encoding was taking so long.

[khp]

On a properly configured system this is not a problem.

The problem in your case is that your system is running another process at 'low' priority. Which causes a competition for processing resources.
This other process could be a screensaver a data miner or something else. Change this to run at 'lowest' priority, or just turn it off, and your problems should be solved.

[thanhvn]

the way i understand it, windows uses a multi-level queue with aging for its priority scheduling. in a nutshell, a process with low priority is like the last person at a check-out line. how many other low priority processes (in this case, only one: cidaemon.exe) is not as important as how many other higher-priority processes (in this case, a whole bunch, most of them are system processes).

in vdub, the process priority is set to "default", which results in a low priority. (i've just changed it to "normal", hopefully this will do the trick. i'll let you know if it does.) however, the way i understand it, the setting of "default" means the launched process will have a base priority inversely proportional to the system's load. that is, on a lightly loaded system, it will have a high priority and on a heavy loaded system, it will have a low priority, and my system's load is only between 5-20%. please correct me if i'm wrong.

[khp]

Originally posted by thanhvn
the way i understand it, windows uses a multi-level queue with aging for its priority scheduling. in a nutshell, a process with low priority is like the last person at a check-out line. how many other low priority processes (in this case, only one: cidaemon.exe) is not as important as how many other higher-priority processes (in this case, a whole bunch, most of them are system processes).

Well if all the higher priority processes are idle (which they should be about 99% of the time) it most cirtainly will make a difference.

On the other hand if a higher priority processes is never idle, the low prioty processes receives next to no processor time. In which case the encoding time would increase by an order of magnitude.

But of course the best way to check into problems like this it to watch the processes tab in the taskmanager to see which processes are using unresonable amounts of cpu time.

Originally posted by thanhvn

the way i understand it, the setting of "default" means the launched process will have a base priority inversely proportional to the system's load. that is, on a lightly loaded system, it will have a high priority and on a heavy loaded system, it will have a low priority.

No, I'am almost cirtain that this is wrong. Default should mean default priority for user processors, which I assume is set to low on your system.

By your argument, a lightly loaded system would endup with a high priority virtualdub instance, which would make the system extremely slow responsive to user interaction, this would ofcourse be quite bad.

Originally posted by thanhvn
and my system's load is only between 5-20%. please correct me if i'm wrong.

Are you saying that you've got a 15-20% cpu load when doing absolutly nothing ?. What system are you running ?

I should probably retract my statement that, your problem is that virtualdub is competing with another low priority process. It appears that your system is hogging rediculess amounts of cpu time for something else. I don't quite see what your system could be using 15-20% of your CPU time for.

[thanhvn]

Ok, after I set vdub's process priority in Options>Preferences>Main to Normal (see attached screenshot), the process stills run at Low priority when called by gknot. I've emailed the contact for vdub and hopefully he/she can give me an answer.

the strange thing is sometimes vdub runs very slow (during the comp check: only 5-7fps, before i went to bed) and very fast (38fps during 1st pass, 51fps during 2nd pass, when i've let run all night). thus, khp is correct in that if higher-priority processes are idle and there are no competing low-priority processes, vdub can be blazing fast. however, this still does not negate the fact that since vdub is a low priority process its performance is totally dependent on the system's load, and i don't like that.

p.s. oh, by the way, my system's load is usually around 2-5% (wiht no user processes running) but sometimes shoots to 20%. and yes, my understanding of the default setting is wrong, as khp pointed out. but the default priority for user processes on my system is normal, as far as i know, since gknot itself (and a whole bunch of other user programs) runs at normal.

[khp]

Then I would suggest that you take a close look at the processes tab in the taskmanager to see which processes are misbehaving.

At the time of writing my system has been running just over 23 hours straight. And the system process that has used the most processor time is explorer.exe, which has used a total of 14 seconds, of cpu time.

It is quite normal, and quite resonable, for the encoding speed to drop significantly, for a second or two, every now and then, when you are activly using the computer for other things.
For example when you open up a text editor or a web browser, I find it very resonable that, that gets a higher priority than virtualdub. Which is why I'am fundamentally opposed to raising the priority of virtualdub.

Now that I think about it, I think there was even a thread on the subject at doom9's.

http://forum.doom9.org/showthread.php?threadid=29920

OK I took part in that one too, looks like my ugly little hands are everywhere

[thanhvn]

thanks, i've read the doom9's thread and most of it i've already guessed. my computer usage is quite bursty: one hour it's heavily used with 8+ windows opened (compilers, internet, music, etc.), another hour it's totally idle. that's why i prefer the encoding in the idle time and as fast as possible. also, i came from the unstable days of windows that i worry about a crashed system wasting hours of my encoding. (i used to crash my win98 system a lot doing experimental things but now that i'm using winxp it's much more stable.) also, the speedup is quite significant, 5-8 hours instead of a couple of minutes. that's a big incentive. anyway, that's just me. thanks for all the help.