Encoding with/without hyperthreading - dual proc

[ninja.rogue]

Hello my friends,
I have installed a dual-boot configuration of my dual Xeon 2.4.
On partition C: I have w2k-pro (which obviously does not have hyperthreading enabled), on partition D: I have xp-pro, which sees 4 processors.
I have tried to test with the same DV AVI file (obtained from Matrox RT2000) of 11' 30" of very complex video. Swimming pool child play.
I have used Procoder 1.035 2-pass vbr 2000-6000-9000 with highest settings, and Tmpgenc 2.59 same settings.
Encoding times are surprising: both Tmpgenc and Procoder are equal or even faster in W2K with 2 processors less...
Procoder is indeed much faster: I have encoding times of 4:1 in W2K and of 5:1 in XP (where it should use 2 processors more...). Using master quality gets 20:1 in W2K and 25:1 in XP.
Tmpgenc has 5:1 speed in W2K and 5:1 speed in XP - here it is quite the same.

Any explanation?
Original file is on a NTFS partition of disk 1 and final file is on a NTFS partition of disk 2.
Cheers people!
Paolo

[bergH]

Hello !

If I understand it right you have 2 real processors ?

TMpgenc uses its own routines for multithreading and Processor controls. TM might recognize that there are only 2 Processors present and ignores the OS settings.

IN the other case the overhead of managing 4 VIRTUAL Processors may take more processing power than it brings to the programm.
IN a benchmark we made some month ago with TM we found out:
There ist no substitute for mHZ accept, even more MHZ. (Megaherz processor power).

Hope I could make my point clear.
_________________
Gruß BergH

[ninja.rogue]

Hi bergH,
sorry for the dual post, but here you did not answer about how much memory to set... as I was asking in the other thread :-)

as far as this thread is concerned - performance with/without hyperthreading - yes, you have well understood: I have 2 real processors - 2 Intel Xeon Prestonia 2.4 ghz.

Tmpgenc 2.59 "should" be hyperthreading-aware - at least this is what you can read from release notes. So it should recognize 4 processors - instead, it just recognizes 2 of them. And I am not even sure that these 2 are the phisical ones...
On this matter, there is a small window on the right which shows just 2 processors - not 4.

Yes, I agree with you on the overhead of managing 4 processors. This could be the issue for having less performance.
I wish somebody else could investigate on this.
mb1, do you still have Athlon?
Could you suggest some other place where to find answers? 2cpu.com?

Thanks in advance.
Cheers.

[bergH]

Hello again !

As said , TM uses its own routines and it RECOGNIZES 2 REAL Processors istead of 4 virtual ones.
And so if there are 2 for TM these 2 will be used.
Thats it.
_________________
Gruß BergH

[SVCDFan]

[Kika]

BTW: Hyper-Threading is a Technologie for brandnew P4-Processors, like the P4 3.06 GHz. So far as i know does it not work with older P4- or Xeon-Processors.

[ninja.rogue]

Kika,
Xeons have been Hyperthreaded before P4s.
This technology has been experimented since 6 months.
Xeons which have Hyperthreading are code-named Prestonia.
As far as their architecture is concerned, they are the fathers of new HT P4s.

[SVCDFan]

Paolo, you are right

Intel® Xeon™ Processor Family for Servers with Hyper-Threading Technology
_________________
Gruß SVCDFan