Comments

Spot|DSE wrote on 4/9/2004, 11:29 AM
Vegas DOES use HT, but not at great extent. It's not an even match if that's what you are asking. You gain a tiny bit of processing power, but we keep HT off on all our machines simply because so many apps don't like it. HT and Photoshop CS and Vegas definitely don't get along.
BPB wrote on 4/9/2004, 11:39 AM
Thanks Spot..I'll just leave it as is.
JJKizak wrote on 4/9/2004, 11:51 AM
Your render time will be 12.4% faster with Hyperthreading turned on.
Try a couple and check the times.

JJK
BPB wrote on 4/9/2004, 11:56 AM
Thanks JJK
I'll give it a try..I thought it seemed a bit slower since I reconfigured my computer to the Protools settings. I'm curious why Steinberg's Nuendo loves hyperthreading and Protools does not...has it to do with background operations?

Can you setup Hyperthreading in a profile or do I have to keep going into BIOS?
Thanks
bpb
Spot|DSE wrote on 4/9/2004, 12:04 PM
Some machines will grant a 12.4% increase, others will grant (according to some users) as much as 20% gain. Other machines, depending on configuration may actually run slower with HT enabled vs disabled. For our purposes, since most of the machines are configured with the same Supermicro and Tyan boards, all using same RAM, mostly loaded with same hardware, we find operation more stable without HT, particularly since as I mentioned, Pshop CS, HT, and most NLE apps don't get along with HT enabled. There is a tremendous amount of information available on this issue on the Microsoft and other websites.
RangerJay wrote on 4/9/2004, 3:46 PM
When you buy a new computer, get one with two processors.

The gains are astounding. Windows XP uses two processors very nicely, and Vegas runs like a charm.

HT is a poor substitute for a dual-processor box.
GlennChan wrote on 4/9/2004, 5:45 PM
The more complex/intensive your renders get the less you benefit from HT. Vegas is made so that one processor handles DV encoding+decoding and all the audio processing, while the other handles all the video FX. On long renders, one of the processors is going to be IDLE most of the time (EDIT: fixed my blooper). Hyperthreading is Intel's trick to make 1CPU do the work of two. It can only benefit performance when it is doing the work of two.

HT speeds renders up by somewhere around 3-9% on real renders (i.e. with multiple filters on DV material), and more for DVD encoding with Vegas+DVD. With Vegas, 3-9% isn't much.
pwppch wrote on 4/9/2004, 7:28 PM
>>Vegas is made so that one processor handles DV encoding+decoding and all the audio processing, while the other handles all the video FX.
<<
How did you determine this?
Spot|DSE wrote on 4/9/2004, 7:55 PM
Glenn,
I think you are confusing dual processing in Vegas with hyperthreading in Vegas.
GlennChan wrote on 4/10/2004, 3:09 AM
>>>
How did you determine this? [what each processor does]

Peter
<<<

Some Sony rep said that's what happened in Vegas in the old forum IIRC. It was a mesage in response to someone who was testing rendering speeds between his dual Athlon system to his single processor pentium. Both machines were the same speed and he was wondering why.

My own testing shows that it's probably true. When you add more video FX, hyperthreading gives less of a performance boost and winXP's CPU usage meter shows that the second processor is doing less. Other people's testing with dual processors show that the second processor usually does very little.

I did *not* test whether the second processor handles audio. Although it makes a lot of sense for Vegas to be programmed that way. And really, it makes like practical difference from an (audio for) video point of view. I just did tests of greater practical value.

>>> I think you are confusing dual processing in Vegas with hyperthreading in Vegas. <<<
Here's my Coles notes take on hyperthreading:
Hyperthreading is Intel's 'party trick' to get 1 CPU to do the work of two. To your OS, it looks like you actually have 2 CPUs (although windows can figure out if you're hyperthreaded or using two processors). Anyways, as you can guess, 1 CPU won't really be able to do the work of two and hyperthreading will only give a small performance boost. Programs however have to be written to take advantage of hyperthreading/dual processors. The program has to be programmed to divide the work between both processors.



(getting off topic) In vegas, I think the programmers just didn't take the time to program vegas so that work is divided onto both processors. Dual processor users report that Vegas doesn't do much with the second processor (although the DVD encoder does). Other NLEs like Final Cut Pro really take advantage of dual processors. The G5 dual 1.8ghz hits 7 streams of real-time whil ehte 1.6ghz 4 streams. There are some other differences between those two Macs but dual processors definitely give a huge performance boost when implemented right.

That was my Coles notes version. For more information than you really want to know about hyperthreading and dual processors, check out http://arstechnica.com/paedia/h/hyperthreading/hyperthreading-1.html

In AE, dual processors give a 10% boost but close to a 100% speed boost when you render farm AE to the same computer. So dual processors can definitely help, but the program has to be programmed to take advantage of it.
JJKizak wrote on 4/10/2004, 5:30 AM
All I know is with my Intel 875 board and P4-2.8 on the same 5 minute
test clip with the Hyperthreading turned on the speed is increased exactly 12.4%. In the task manager both CPU's vary from 50% to 95%
and vary between processor #1 and #2 with #1 taking on the primary load. I really don't care what it's doing as long as it is faster.

JJK
Cheesehole wrote on 4/16/2004, 6:46 AM
I also remember a Sony (SoFo) rep telling us that one processor handles the rendering while the other compresses the rendered frames to DV. I typically get 60-65% usage unless there are tons of FX and then it is more like 54%.

Dual processors deliver two big benefits to Vegas:

1) Ability to render two sessions at once, or render one session and edit another. AFAIK most NLE's don't even let you open two instances of the application.

2) Editing/Navigation operations on the timeline can easily use 95%+. This is most apparent when playing the time line and interacting with the interface (Zoom, Scroll, Click/Drag an Event, etc) - so both processors are almost fully utilized to keep the interface and preview frame rate smooth while editing.

And some renders do use both processors. Encoding to Windows Media 9 for example can use 95%.

I hope to see improvements in Vegas 5!!! It's true that other NLE's take better advantage of dual processors - or at least they appear to.
pwppch wrote on 4/21/2004, 8:09 PM
Well, being one of the Sony programmers - specifically on the audio side - I can tell you this is not how it is done.


Performance is not a X2 or even close just because of dual proc. It is very easy to saturate both CPUs and still not see a real net gain. Just because both CPUs are at 100% does not mean they are being used efficiently. A more efficient SMP aware host may balance the load. Remember disk I/O is very time sensative. You can be maxing out the processing using only 40% of both CPUs, but because the critical path is disk i/o, you will never see 100% usage of both CPUs.

There are even more issues when hyperthreading is tossed into the mix.

Lots of variables here. Simple benchmarks don't explain or show the entire picture and can be very misleading, if nothing more than marketing hype.

I can assure you that we do take the time and take SMP performance very seriously.

Peter