Meltdown / Spectre patches - any performance hit to Keyshot?

[Matt.Kinsington]

Heard about the Spectre / Meltdown problem, and patches to fix it from both Microsoft (for Windows) and Intel for the processors themselves.  Supposedly those patches can cause a 5-20% performance decrease (approximately) depending the model of processor and age.

They say "most users" doing things like "web surfing" and "email" should not notice any performance hit.  Wondering if power users doing CPU rendering have noticed any performance loss after these patches.

Anybody applied these patches?  What kind of rendering performance hit have you seen, if any??

[Matt.Kinsington]

My computer doesn't have these patches yet.  Is it ok to patch, or will rendering be slower?

[Will Gibbons]

Not sure yet. Would be interested to hear what you find out.

I lucked out and built my most recent machine on an AMD chip about 2 months before this was revealed.

[Matt.Kinsington]

Nobody noticed any performance drop?  That's good.

I haven't been rendering lately to test it.

[georgecox]

Our system administrator says there is no drop despite we have those patches already and rendering went as usual. Anyway, thanks for the warning.


George Cox
domyhomeworkonline

[soren]

First, a disclaimer: We have not done extensive testing of the effects of the patches fixing spectra and meltdown, so what follows is a theoretical prediction. In addition, the patches and the security vulnerability they address are complex, so the discussion below may not be entirely accurate.

The vulnerabilities discovered with Spectre/Meltdown primarily deals with cases where a process is accessing OS memory and user memory often. This is not the case with KeyShot when rendering: when KeyShot renders it is almost exclusively using user memory. The likelihood of the patches impacting KeyShot is fairly low. KeyShot does use the operating system memory, but primarily when saving files or communicating over the network, but any performance impacts are likely to be small in these cases.

However, if other processes are running on the system that make extensive use of the operating system kernel while KeyShot is running, performance can likely be affected (this includes drivers and services).

KeyShot depends on certain drivers for its operation, in particular the GPU driver (for displaying the realtime view and the geometry view). Some of these drivers can be very invasive and this is not something we have any control over - we have seen cases where a vendor's graphics card driver took over certain key operating system features which caused degradation of performance in KeyShot in very specific circumstances (even without Spectre/Meltdown).

Finally, it is recommended that you keep drivers and operating systems up to date: security vulnerabilities can be devastating.

Hope this provides some insight into this and helps reduce any concerns you may have. If you are in doubt, the only way to make sure is to test it.
Søren