A few questions, advice needed!

[Gary Kleiner]

Chris,

1)With Dual core, you can have two threads. Leaving the default set to 4 is fine (it will only use 2). If you want to do other work while the render is going on, set it to 1.

Gary

[Chris Young]

Gary ~

Thanks for that, thought that was the case using only two but didn’t twig to the fact of using only one whilst doing something else.

Cheers
Chris Young
CYV Productions
Sydney

[Terje A. bergesen]

Just curious, why would it only use two threads? One CPU can, and should to take max advantage of it, run multiple threads during rendering.

—
Terje A. Bergesen

[Chris Young]

Terje ~

I think what Gary is getting at is, as I understand it, is that the Pentium D Dual Core procs are just that, dual core, not hyper-threaded as in the P4 3.2. The only Pentium Dual Core with HT is the Extreme edition, which for the massive increase in price I couldn’t justify for just for the added benefit the HT would offer. With my P4 3.2 with HT I run both threads for rendering and am doing the same using both cores with the dual core box. The benefit of the dual core lies in the two separate execution cores. A big step up from the HT P4 series. Basic Vegas tests I have carried out here show me that the 3.2 dual core is considerably quicker than my P4 HT 3.2 unit. If I can do two separate things, such as render and edit with one execution core and one thread for each job I think it will prove quicker and more efficient than doing two separate jobs at the same time with the P4 HT 3.2 using just the one core trying to maximise the two threads available. These things I will no doubt find out as I test these theories out. What gave me some understanding of the differences and benefits between the P4 HT and Pentium D dual core units was a demo on the Intel site. If you go to:

https://www.intel.com/products/processor/pentiumXE/

and click on their dual core demo video you will see why I am asking these questions re Vegas with the Pentium D/Core units. Mind you this is all new to me so I may have it wrong but no one has given me any better insights so far.

Re my Radeon dual display problem with Vegas not seeing the ‘secondary display’ after some setting changes in the ATI GUI it is now working. Problem is I am not sure exactly what I did to get Vegas to see it! Geez I hate that.

Chris Young
CYV Productions
Sydney

[Terje A. bergesen]

There is no doubt that a dual core CPU is faster than a HT CPU. There is also no doubt that running two threads for rendering in Vegas on a dual core CPU will be faster than running one thread. Also, if you set the number of threads to 4, I would assume that Vegas will use 4 threads for rendering, not two, no matter what your CPU design is, how many cores it has and whether it is hyper threaded or not.

My computer is still very old, it doesn’t have Hyper Threading and it isn’t Dual Core. I have not tested Vegas threading at all, but I have been playing with some video programming on my own that is similar in work load to rendering video. Splitting the work into 2-4 threads, depending on the size of the video file, gives me a good speed boost even though I do not have two cores nor do my CPU support hyper threading.

If you have a dual core CPU I would expect that using 2-4 threads would be a little low for rendering, having 6-8 seems reasonable, but then again, I have not tried this with Vegas.

Even though rendering is very CPU bound, it is also disk bound and memory bound since we are dealing with a large amount of data. Running multiple threads for rendering, no matter what your CPU architecture, should therefore increase rendering speed no matter what. Too many threads of course is not a good idea though, since the OS will spend more time switching between threads than actually running them.

—
Terje A. Bergesen

[Chris Young]

Terje ~

Vegas 6.0 supports up to a maximum number of four rendering threads, selected under the options/prefs/video tab. From that I gather this will make best use of the Dual Core Extreme HT editions which have the four logical CPU’s. With the Pentium D 840 processors you have only the two logical procs and no HT so it seems to me that Vegas 6.0 will have no render benefit with more than two threads enabled. There is quite a good analysis of this at:

https://www.tomshardware.com/cpu/20050405/pentium_d-03.html

Interestingly when it comes to video rendering the standard dual core Pentium D 840 without HT is actually faster in some cases than the dual core extreme procs with HT enabled in bios. I can’t say I fully understand the why of this but the results at:

https://www.tomshardware.com/cpu/20050405/pentium_d-18.html

are interesting to say the least. The previous pages to the link above were also food for thought. Still trying to get my head around all this dual core info and the best way to use it with Vegas.

Chris Young
CYV Productions
Sydney