I installed Linux Mint 20 on my AMD 8 cores with a GTX 1650 using Nvidia drivers 470.74, and there is a dramatic incrase in speed on CPU, and a noticeable increase on XPU compared to Windows 10 Workstation.

CPU:
Linux 20:54
Windows 55:07

XPU:
Linux 09:34
Windows 10:49

You are using "biased" as if it meant something for you, have you done research on what is actually biased or you are just spouting it? I use both Houdini and Blender, and it's much better than using any of them alone.

@GCharb, indeed the speed gain is insane Oo

Rhino Scene

Windows 10:

CPU : 12:08
XPU : 03:43

Linux (POP OS 21.04)

CPU : 04:59
XPU : 03:16

TR3970X / RTX2060 super

EdganHomt
You are using "biased" as if it meant something for you, have you done research on what is actually biased or you are just spouting it? I use both Houdini and Blender, and it's much better than using any of them alone.

A biased render engine is not physiqualy accurate, it uses algorythms and tricks to approximate the physics of lights, making it faster, but innacurate, this is rendering 101.

As for blender, it is very limited, and everything Houdini does it does better than blender, I see no points in using both TBH.

One of the things that I never understood about the way blender work is why on Earth, in 2021, a DCC app would makes a primitive like a sphere parametric at creation time, but then as soon as you deselect it it becomes a static, non parametric object, makes no sense to me that they never fixed that, this is one of the reasons most pros wont even have a serious look at blender!

PaQ WaK
@GCharb, indeed the speed gain is insane Oo

Rhino Scene

Windows 10:

CPU : 12:08
XPU : 03:43

Linux (POP OS 21.04)

CPU : 04:59
XPU : 03:16

TR3970X / RTX2060 super

Pretty amazing TBH, I am looking at moving to Linux as we speak, well worth the effort IMHO, especially since there is a Linux version for most of the tools that I use!

PaQ WaK
@GCharb, indeed the speed gain is insane Oo

Rhino Scene

Windows 10:

CPU : 12:08
XPU : 03:43

Linux (POP OS 21.04)

CPU : 04:59
XPU : 03:16

TR3970X / RTX2060 super

That looks like a bug. The difference between the XPU tests is more plausible.

jsmack
That looks like a bug. The difference between the XPU tests is more plausible.

A bug that would make Karma really slow under Windows, 2-3 times slower?

GCharb

jsmack
That looks like a bug. The difference between the XPU tests is more plausible.

A bug that would make Karma really slow under Windows, 2-3 times slower?

Yes, a performance difference in that range is surely a bug. Differences due to kernel scheduling are generally not going to be orders of magnitude. There has been a bug in karma in the past that caused this large of performance difference when using certain texture formats that has since been fixed.

jsmack
Yes, a performance difference in that range is surely a bug. Differences due to kernel scheduling are generally not going to be orders of magnitude. There has been a bug in karma in the past that caused this large of performance difference when using certain texture formats that has since been fixed.

I would love to hear what SideFX has to say on this, I have seen other apps run faster on Linux, but not such a difference, someone needs to make tests between 18.5 and 19 on Windows, to see if that's the case, and if you are right, it means that SideFX hasn't fixed a major bug in 9 days!

jsmack

GCharb

jsmack
That looks like a bug. The difference between the XPU tests is more plausible.

A bug that would make Karma really slow under Windows, 2-3 times slower?

Yes, a performance difference in that range is surely a bug. Differences due to kernel scheduling are generally not going to be orders of magnitude. There has been a bug in karma in the past that caused this large of performance difference when using certain texture formats that has since been fixed.

Are there textures in the Rhino scene? I've converted textures to RATs and have not seen differences in render times using Windows. Maybe the bug returned?

Andy_23
Are there textures in the Rhino scene? I've converted textures to RATs and have not seen differences in render times using Windows. Maybe the bug returned?

No, only two simple MaterialX shaders that can easily be replaced with Principled shaders, but it seems to me that if 19's Karma was much slower than 18.5 under Windows, that users would have reported it on the forum after 9 days!

This bothers me, so I modified the scene to use Vex shaders instead of MatrerialX shaders and rendered it in H19 in linux, I lowered the sample count to 256 to make it faster, since it's a CPU only test, I will re install Windows 10 Workstation and render the scene in both H18 and H19, to see if this is a Windows bug, or if indeed there is a huge render difference under Linux!

Linux H19 CPU render time: 8:18
Windows H18 CPU render time: 11:56
Windows H19 CPU render time: 26:49

I attached the VEX scene

Rhino Vex - TR3970X - CPU

Linux H18.5 : 02:27
Linux H19 : 01:38

Windows H18.5 : 02:47
Windows H19 : 05:53


Edit : On windows I do however have a bunch of compile error msg, and for some reason the bg color is back.
There is definitively something odd in H19 Windows.

PaQ WaK
Rhino Vex - TR3970X

Linux H19 CPU render time: 01:49
Windows H18 (18.5.672)CPU render time: 02:47
Windows H19 CPU render time: 05:48

Edit : On windows I do however have a bunch of compile error msg, and for some reason the bg color is back.
There is definitively something odd in H19 Windows.

Same here, render time is more than twice the time as the one in H18 windows and Linux, so Linux isn't really faster, so back to Windows for me, less hassle!

As for the errors, I created the file in H19, there seems to be compatibility errors, I have redone the file in H18 and there is less errors in H19 now!

PaQ WaK
Rhino Vex - TR3970X

Linux H19 CPU render time: 01:49
Windows H18 (18.5.672)CPU render time: 02:47
Windows H19 CPU render time: 05:48

Edit : On windows I do however have a bunch of compile error msg, and for some reason the bg color is back.
There is definitively something odd in H19 Windows.

in linux H18 what the render time?

I have updated the numbers, using the last version from GCharb, testing H18.5 and 19 on both OS.

PaQ WaK
I have updated the numbers, using the last version from GCharb, testing H18.5 and 19 on both OS.

Man, I need a 32 cores Threadreaper, thanks for sharing, there is definitely a problem with the Windows H19 release!

re: windows slower than linux

We're aware of what's causing the issue now and we're working on a solution.

Pyro Scene

Windows 10:

XPU : 00:26s

core i7 11800h, RTX 3070 8gb

chrism
re: windows slower than linux

We're aware of what's causing the issue now and we're working on a solution.

That's great to hear!

This is unfortunate, as a great number of motion graphics freelancers and small studios, who may be evaluating H19 Karma right now for their workflows, will be doing so under Windows...and we're talking about 2x speed decrease because of this bug! In any case, I really appreciate the quick response from SideFX and all the very visible improvements and care put on Karma on H19!