DR with 8-core and quad-core slower than quad-core alone ?

[Pixelsonic]

Hi,

I´m having a strange problem with a scene that I´m trying to render with DR on two computers:

- Quad Core 2.4 GHz, 6 GB Ram, Vista 64 business, VRay 1.5 RC2, Max Design 2009
- Mac Pro 8 Core, 6 GB Ram, Vista 64 business, VRay 1.5 RC2, Max Design 2009 (Slave)

When rendering the same image with both machines in DR mode, the rendering seems to take much longer than rendering with the Quad Core alone. Also some buckets from the slave machine freeze where they start for 10 hours...

Does anyone know what this might cause ? Is it possible that the bucket size (64) causes this problem ?

Thanks,
Martin

[stevesideas]

There seem to be a few people around at the moment having these problems.

I resolved my similar issues by turning off the hardware-prefetch option in the biod. I think also someone mentioned about turning off the snoop option...try both though, it worked for me.

Other than that, someone did mention it might be bad memory, so it may be worth checking your memory sticks one at a time.

Also, check the cpu throttling settings in bios. Im not sure if that would do it, but if your pc isnt being cooled enough it may throttle back under load.

Good luck

[Pixelsonic]

Thanks. I don´t know how to change bios settings on a mac though.

Also previously I´ve been using dr with Max 9 and these problems did not appear
then with the same machine, just a different Max version.

So I guess it might be something with max 2009 and vray ?...

[DP]

its not the ram : core ratio kicking in is it? with a quad you have 1.5gb per core, with the 8 you have 750mb..