Performance with i7 920 problem

[Anonymous]

Hello all!

Finally friend of mine bought new archicad machine.
We have xp pro X64 running. hardware in shrt is x58 mainboard, i7 920 (8 cpu's in device manager). 2x2gb ddr3@1333, 300gb velocity raptor + 1tb wd 32mb sata2, ati hd 4870 1gb ddr5, chieftec 600 wat.

Problem is that when he wants to render regular non complex scene it takes much longer than on his laptop with c2d cpu (1 year old machine 1gb ram).

Starting task manager it is clear that in process c2d uses both cores while i7 920 uses only one which is 13% of all cpu power.

We did install latest Archicad update. Doesnt help. In one moment we did saw real cpu power when soon after rendering started all 8 cores were powered up and it was amazing to watch. Never happened again. So it's working on 13% cpu power:(

Are we missing something? Some internal archicad settngs? bios option? anything?

Thanks everybody!

[Anonymous]

Me agian. There must have been other people with i7 920 cpu. Please can you guys tell which OS are you running. Windows changing is only thing that comes to my mind.

All the best to all!

[Anonymous]

Hi Viljam,

In the render settings, check that the anti-alias slider is in the same position on both machines. It needs to be set to one notch below best for all cores to be used.

This article says that using the realistic sun also effectively limits the engine to single core. I usually render using this setting and it seems to always uses all cores for me, which is strange. Has anyone else noticed if this is the case or not?

Also note that the i7 processor is still only a quadcore, and uses hyperthreading making it appears as 8. This article mentions that lightworks may not be able to take advantage of these virtual cores, which maybe part of why it appears never to be running at 100%

[Anonymous]

Thanks man! This solved a lot of problems.
Even with realistic sun it works all cores are working. It is a bit slower but looks much better. Only important thing was anti-aliasing as you described.

It's a pitty that Archicad is not supporting more than one cores in general. All cores come to power only when rendered image starts to appear. It still uses one core for precalculation befor rendering start to appear.

All the best and thanks so much!

[Anonymous]

viljam wrote:
Thanks man! This solved a lot of problems.
Even with realistic sun it works all cores are working. It is a bit slower but looks much better. Only important thing was anti-aliasing as you described.

It's a pitty that Archicad is not supporting more than one cores in general. All cores come to power only when rendered image starts to appear. It still uses one core for precalculation befor rendering start to appear.

All the best and thanks so much!

No problem!

When you say "it's a shame Archicad is not supporting more than one core" I presume you actually mean just Lightworks, as ArchiCAD 12 can now use multiple processors for most complex operations, like elevation generation etc.

For future reference it is also worth adding your version of AC, computer spec and OS to your signature to help others when answering questions.