Very cool rendering performance improvement

B

bbinnard

Well-known member
I was rendering an HD video in VMS10 and thought I'd check how my i7-920's 8 CPUs were doing. So I started Task Manager and noticed that only 5 of the 8 CPUs seemed busy. (My VMS10 is set to 8 threads for rendering video.)

So I started Resource Monitor and clicked on the CPU tab. What I discovered was that most of the time 3 CPUs were "parked". When parked they were doing no work (utilization =0.) So even though VMS10 was set to use all 8, only 5 were actually working.

Why? Well apparently Microsoft decided that its OK to disable some CPUs to save power (and reduce chip temperature.) But my electricity bills are OK and my PC has a good 3rd party cooler. I figured I'd rather have all 8 CPUs working on rendering.

I Googled "CPU Parking" and found that, for each Power Scheme defined in Control Panel/Power Options there are 2 parameters that control CPU parking: Min and Max. Microsoft sets Min = 0 and Max =100 which means at any time all of the CPUs can be parked. It is not clear how Windows decides which CPUs to park when, but it apparently does.

I found the following fix to disable parking:

These steps allow a multi-core CPU to use all of its processors when rendering:

- Go to Regedit

- Find this key:- " 0cc5b647-c1df-4637-891a-dec35c318583 "

- Within this key, there is a value called: " ValueMax "

- This value represents the % number of cores the system will park - the default 100% ie: all Cores are potentially park-able

- Change the value from 64 to 0 so the " ValueMin " and " ValueMax " are both zero

- You will have to find the key a few times and repeat the process for each time it is found - the number of instances will depend on the number of power profiles in your system [ in my DAW it was only found twice ]

- Do a full shutdown and power-off and cold-re-start

This works. (You just have to restart after making the change; power off is not req'd.) After the change what I noticed is 2 things:

1. All CPUs are working during rendering

2. The workload is spread much more evenly across the CPUs than when some were parked

Here is the webpage I found that has lots of background and additional links on this:

http://forum.cakewalk.com/tm.aspx?m=1861804

From what I can tell from initial tests this change has speeded up rendering on my system by about 20%. I think this is a nice performance improvement for a simple registry tweak.
 
Interesting. All my cores seem to be operating fully when I render, and I've not had to hack the registry. That's with Vegas Pro 8, Pro 9, and Avid MC4 and MC5.
 
PerroneFord said:
Interesting. All my cores seem to be operating fully when I render, and I've not had to hack the registry. That's with Vegas Pro 8, Pro 9, and Avid MC4 and MC5.
Click to expand...

Are you running Win7? CPU Parking only exists in Win7. It's a new "feature". (I know, I should have mentioned that.)
 
I wonder if perhaps hardware manufacturers (not Intel, i mean whoever puts together the whole computer) decide for themselves what presets to use, so the settings may vary between different models and different manufacturers?

Anyway, sounds a bit like overclocking - safe enough so long as your computer runs nice and cool...
 
now did you keep the stock setting on SVG10? or did you also change settings with in vegas )or stock settings?thanks
 
sammysammy said:
now did you keep the stock setting on SVG10? or did you also change settings with in vegas )or stock settings?thanks
Click to expand...

I have Vegas Movie Studio10 which defaults to 8 threads. I don't know what Vegas Pro 10 does but I assume it is similar.
 
hmmm...I go to regedit and I come up with "HKEY_ClassRoot", HKEY_Current User" etc.. Can you tell me more in detail where this would be? I tried to search it but it doesn't come up. I do have win7.Does this only apply to SVP10?
 
Hi Guys. I'm with Perroneford. I'm running Windows 7 Ultimate 64 bit with Vegas 9.oe on an AMD II x4 620 proc . I have no parking issues at all, (and I think I would with this proc), mainly I believe, because I've set my my Performance Options to Adjust for Best Performance. This, from what I've read, turns off parking on desktop (Win7) machines. Am I wrong? For instance, right now, my machine is virtually stopped, my CPU is at 2 - 5% utilization and is only really using CPU3 (out of four cores). No Parking at all, when you would think you should be seeing some.

I've done a bunch of reading on this issue today, and believe that what you are discussing is more relevant to Windows Server 2008 situations. I could find nothing on Microsoft or other sites that actually leads me to believe that parking is an issue with at least the version of the OS and the proc I run. I bought this proc specifically because it supports Hyper-V and allows me to run virtual instances of the OS (namely XP and Server for example). Also, if you read the detailed MS docs, it does not seem like you need to hack the registry to make this work properly.

So perhaps this is only an issue for specific processors, manufacturer settings and or OS versions?
 
JoeJITSU said:
I found it. Now I only changed it once. What does it mean that you have to change it twice or more?
Click to expand...

There is a separate set of values for each Power Profile your system has defined. Mine has 2: one that puts my PC to sleep after 10 min. of idle time, and one that never sleeps (for rendering when I am away from the PC.)
 
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No. It's more than that. Power options are one thing. Performance options are about a much larger set of variables. There are a huge set of choices about whether the computer shows icons on the folders, etc. IT's not just whether the power is shut off after x minutes.
 
I have all the power saving features in BIOS and OS turned ON which means my CPU cores are parked when there's no demand.
When there's demand, it gets un-parked as it's supposed to be. In OP's case, I think there's something wrong with his computer and he needed to fix it that way.
Unless your computer shows abnormal behaviors like OP's, messing with such settings might wreak your system.
 
To clarify a couple of things:

1. Since making the registry tweak originally mentioned I've completed rendering 18 separate AVCHD files and assembling them into a completely full Blu-Ray disk (Vegas MS10/DVD Architect). I didn't write down my render timings but in general my renders run in about 80% of the time they used to before the registry tweak. For me, this is the kind of tweak I like to do.

2. If you look at the registry it is clear there are many (and obscure) settings for each "Power Profile" you set up. One of them is the parameter that controls parking. My system has 2 profiles: one that puts the system to sleep after 10 idle minutes, and one that keeps it running forever. Normally I use the first one but when doing long renders I switch to the 2nd so I can leave the system and do something else.

The parking parameter is just one of the many in each power profile, so I had to tweak it in both groups. Since I had no idea what all the other stuff in each group was used for I left it alone.

3. The Microsoft info on parking is rather obscure, but its focus seems to be on reducing laptop power requirements. My guess is it applies only to the combination of Win7 and an Intel multi-threaded CPU. MS works very closely with Intel so it does not surprise me that AMD CPUs do not get treated the same.

4. I don't know if there are BIOS settings that could affect parking. This would be an interesting one to learn about, but I have no idea how to do that.

5. If there is "something wrong" with my system I'd sure like someone to tell me what it is. It runs like a clock and is the most reliable and responsive system I have ever owned (partly because I upgraded to an SSD boot drive when I switched from Vista-64 to Win7-64.)

The bottom line for me is that as a result of making what for me was a simple registry tweak I got a significant performance improvement in the most CPU-intensive work I do, and there were zero adverse side effects. I'll make this kind of change any time one becomes available.
 
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