Finish Gknot/VDub jobs 25% faster

[cornetet]

I just found out a way to increase the performance of a Gknot (VDub) job by 25%. That is to say, have the job finish 25% quicker. This advise is only available for Win2000 users, as I can not vouch for Win98 and WinXP users.

Here's how the performance increase works:
> Once a 'job' in Gknot starts the first-pass thru VDub minimize all windows. Again, a 'job' must currently be running.

> Hit Ctrl+Alt+Del and the WINDOWS SECURITY window will pop-up.

> Click on the TASK MANAGER button. Now click on the PROCESSES tab.

> Go to the very bottom of the list and find the virtualdub.exe listed under Image Name.

> Right-click on the virtualdub.exe and then set the priority from LOW to HIGH. Then close all the TASK MANAGER windows.

> !IMPORTANT! DO NOT set the priority to REALTIME. This will completely LOCK-UP your Win2000 until the VDub job is finished. You'll have no mouse-pointer, no way of moving within Win2000 if REALTIME is set.


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Your Win2000 Oper System will now seem very very SLUGGISH. Thats because most of the resources to run Win2000 (processor & memory) is now DEDICATED to processing your VDub job. I've found using this technique gets my Vdub jobs done 25% faster than before. You may want to consider NOT DOING THIS if you need to continue using Win2000 while the 'job' is processing. The performance of Windows2000 will dramatically nose-dive.
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[MePHisto]

Thanks cornetet,
good advice

Speeding up such long jobs is important :)

Just one question, is not the same as setting the priority in VDub?

I mean the "Processing thread priority" popup
You can also set it as the program default

I am not using W2000, I just would like to understand since I am using it too...

[Doom9]

when you change it in virtualdub it's set for all future virtualdub sessions, when you set it in the task manager it's only set for the current session. Personally I prefer low priority since I want to use the PC while it's encoding and I don't mind waiting a tad longer (btw.. the 25% imho is an exaggeration.. if you don't touch your PC during the encoding session the priority hardly matters)

[N_F]

Just like Doom9 says, if you don't use your computer for gaming och watching movies you're not likely to save any bit time wether you use idle or highest, if you don't touch the computer the encoding time should be the same within a few minutes perhaps.

I personally have mine set at idle as default since I like to be able to listen to music and watch movies while encoding.

[MePHisto]

Ok, Ok,
thanks to both :)

I try not to use my PC while encoding (i prefer to have 'as less time as possible') and I was just wondering if there was any difference between the two ways of setting the task priority
Just that, not more

I use XP and I was a little attracted by the 25% of speedup (it's a lot) but, as you say, it's over-estimated

I will have a try anyway...maybe...

[cornetet]

You guys with BARN-BURNER processors probably DONT see that big of a difference... but guys like me with an older computer because the wife wont let you go get a new $2000 system every year, will have to do what I do.:D

So if you have a GHz+ processor you WONT find anything I have to say as GroundBreaking... But those of you with older systems may want to try what I've tried:

Since my processor is older (Intel P2-450MHz), this thread priority seems to be greatly needed, to suck as much processing power as it can get to process the job.

I have verified my performace increase by sitting there with a stop-watch and timing how long VDUB takes to go from 1% to 2%.

I then take this amount of time, figure out how many total seconds it took to go from 1% to 2%. I then multiple these total seconds by 100 to figure out how many total seconds I am to expect for the WHOLE first-pass project.

I then take the total seconds divide by 60 to get minutes, then divide by 60 again to get an estimate in hours. I then know how many hours to come back to check the first-pass results.

I then do the same for the second-pass.

Anyway, with bumping up my priority from LOW to HIGH I am seeing about 20-25% faster times....

[MePHisto]

Hey cornetet, wait, don't get upset
Saying that "it's over estimated" I didn't ment to insult you or boubt about your words

Sorry if I did that :)

[N_F]

@cornetet

Perhaps you have some background program lying around that takes up 20-25 % of your CPU power? That would explain that big speed increase you get. If you're running 2000/XP you can check your CPU load by pressing CTRL+SHIFT+ESC.

[METEO]

Also when you encode, tunf off the audio in Virtual dub. This sometimes may help speed up the process

[cornetet]

Thanks for all the advise.. I'll continue to look for any processor jobs that are draining things away from VDub. No feelings were hurt...

One man's epiphany is another man's discrepancy.

SECOND QUESTION= since an avg Gknot job for me takes about 12-16 hours to complete with my P2-450MHz.... if I were to consider getting a new computer at around 1.6GHz... what time saving am I to expect??

An avg Gknot job for me is a 2CD filesize yielding about 1200kBits/sec to 1800kBits/sec (I shoot for a Bits/Pixel*Frame of right around 0.30 but nothing less than 0.27)

[TheWEF]

roughly 4 times faster.

wef.

[JohnMK]

Changing CPU priority doesn't have the described effect. Thank you for the well-intentioned advice, but taking it won't make the encode go any faster, it'll just make your system less responsive and less fluid. For a true speed increase we have to wait a few weeks or longer for YV12 support to be fully tested and certified in VirtualDub/Avisynth.

[colordog]

Cornetet -

My encoding setup takes roughly 1.8 - 1.9x the time length of the movie. That's with the following setup:

Pentium 4 / 553MHz FSB / 1,066MHz 512MB RIMM RAM
Intel 850E MB / ATA-100 drives / WinXP SP1

using:

GKnot 0.26.1b / DivX 5.0.2 / 1-disc (700MB) / 2-pass / Field deinterlace / bicubic neutral / 128kpbs variable MP3 BeSweet audio

Hehehe... I have to say that I'm pretty happy with this setup, becuase I can easily encode two entire discs while I sleep, and often three - plus also while at work or away from the computer. True, this'll still be slower if you want two-disc surround-sound audio encodes, but this works awesome for me.

======================================

My previous hardware setup did encoding with the same software as above, but with the hardware below, at roughly 2.5x the time length of the movie:

Athlon XP 1900+ / 266 FSB / 512MB DDR266 DDR RAM
VIA KT266A / ATA-100 drives / WinXP SP1

Hope this helps ya out.

[theReal]

When you're leaving your computer alone, the encoding process with low priority takes about 99% cpu power, the same as with high priority. With realtime, it takes 100% that's why it completely locks the system - it won't even give kernel tasks any processor time.

If the encoding process doesn't use 98-99% of the cpu power when it's in idle priority mode, then some other process is stealing cpu power from it - find this process and eliminate it :D

The only "advantage" encoding at high priority has is that you can't even check your emails while encoding, or at least it takes half an hour for the program window to open...

[JohnMK]

Exactly. There's no point in assigning high CPU priority. Thinking it gives any benefit whatsoever really demonstrates a sincere and unfortunate lack of knowledge about how PCs and OS's work.

[JohnMK]

Figured this deserves to be in this thread: YV12 will soon make encoding 25% faster or so. :D For real.

[colordog]

Couple questions:

1) What's YU12?

2) Is it likely to be integrated into Gordian Knot? That is, which components would use it?

[cult]

have a look at avisynth forum for YV12

[Mistar Muffin]

I have a 1.4ghz Athlon and w/out IVTC (force film usually works) and only b-frames at 640 res, the first pass usually takes a itty bit longer than realtime, meaning a 2 hour movie may take about 2hr 30 min, however, the second pass is faster (cause i use divx 5.02), and it only takes like 1hr 45min for second pass. So you're lookin at a huge increase there bub. Also I am running Win XP Pro and those times are w/out that thread priority tweak.