Low cpu usage :(

[Geezer]

Hi,

I built a dual xeon e5-2670 machine and it feels a little slow when I start rendering the secondary GI phase.
Any ideas how can I speed it up?

(Asus Z9 PE D8, 64b ddr3 1333 RAM, Win7 64 bit op with latest updates, radeon 7800 gpu)

Cheers,

[maru]

Hi, is this happening in any scene? Even in an empty one, or if it's just something simple like a teapot and one Corona light?

[Geezer]

This is a quite simple scene but will try it with a basic one at home as you recomend it.

I know dual xeon cpu systems will never be as responsive as a fast single i7 but it feels slow compared to its self.

[maru]

Is the CPU usage also low during the final rendering, or only during the GI calculations stage?

[Geezer]

The actual rendering phase is using all cores a 100%.
I only see slow speed during the scene setup and secondary GI part.

[maru]

Ok. Please check whether it's happening in any/simple scenes, or only in one specific scene.

[Geezer]

I also made chages to the bios similar to these settings except the ram overclocking (speed got better)

[Geezer]

So I checked it with a simple scene and the secondary gi calculation is only using 50 % of the cpus power.
After that is goes up to a 100% usage.

[Ondra]

CPU usage can be lower at the beginning of precomputation, but it should go to 100% after few seconds. If you change preset to animation, do you achieve 100% usage by the end of precomp?

[Geezer]

I will try it at home, thank you.

[vinbarg]

Me also, when i start rendering, i got about 5-10% on parsing the scene, 60-70% on GI, than during the rendering it reach 100%

[Geezer]

So I tried the animation uhd cache way and the cpu activity was around 40% for the whole time.
Very basic scene only using corona sky.
Same scene runs ok on my i7 workstation.
As the rendering started it went up to a 100%.

I also checked my cinebench score and the machine is underprerforming there as well :(
It should make a solid 2000 score but it gives me ~1200 points.

Any ideas guys?

[Geezer]

Well guys I have good news.
Installed windows 10 and a few updates and made the changes in the bios listed in the youtube video above.

The cinebench scores are back around 2000 and the secondary GI rendering speed is much better now.

I think the problem might came from memory channel and rank interleaving. (from 02:00 in the video)

Instead of 4 and 8 values I had "auto" there.

As far as I seen in forums RAM setup can have a big impact on xeon systems.
Im not an expert so let me know if its bullshit.

Cheers.

[Geezer]

Is there any way a system update for win7 or win10 can affect the performance like this?