Terragen and a Core i7-13700K

[Rudolfking]

Hi all,

Version: 4.6.31 Free
Scene: any (benchmark, empty opening scene...)
CPU: Intel Core i7-13700K
Motherboard: Gigabyte Z790 UD AX
Latest drivers installed, BIOS updated
Memory XMP profile active, CPU core enhancer OFF (as per Intel 12-13th gen recommendation)
This CPU has 16 cores, 8 Performance cores (or P-cores) and 8 Efficient-cores (or E-cores).
Windows 10, all updates installed, High Performance power option selected.

Issue: When I am rendering, and the Render window is in focus, CPU usage is 100% and the render is lightning fast (3:30 for benchmark scene), both P- and E-cores are maxed out at 100%. If the Render window loses focus, P-cores go 0% but E-cores remain 100%, drastically cutting back render speed (benchmark result drops to 9:45, almost 3 times slower!!). I guess sometimes it'd be cool to watch a movie or work on other things while rendering
E-cores does not even have hyperthreading (?), so essentially (I guess) the renderer runs with 24 threads on the remaining 8 E-cores.

Let me know if you are aware of the issue or I can help trying out drivers/updates/settings.

Thanks!
Rudolfking

[WAS]

E-cores does not even have hyperthreading (?), so essentially (I guess) the renderer runs with 24 threads on the remaining 8 E-cores.

If it doesn't have hyper-threading, than those 8 cores is running at 8 threads. With hyper-threading, 8 cores should act as 16 threads

[Rudolfking]

I know. I found the correct info as well: This CPU has 16 cores, 8 with HyperThreading, 8 without, so 24 virtual cores (2*8+8). And Terragen recognizes 24 cores (correctly) and runs the renderer with 24 render threads (correctly). And if the Render Screen has focus, it uses 24 virtual cores (CPU at 100%, good), if it loses focus, it uses 8 virtual cores (CPU at 33%, bad).
My guess is some energy saving option hidden somewhere, but I tried to turn off all of those both in BIOS and in Windows. And I guess there is some potential fix for this from the application side as well...

[WAS]

I know. I found the correct info as well: This CPU has 16 cores, 8 with HyperThreading, 8 without, so 24 virtual cores (2*8+8). And Terragen recognizes 24 cores (correctly) and runs the renderer with 24 render threads (correctly). And if the Render Screen has focus, it uses 24 virtual cores (CPU at 100%, good), if it loses focus, it uses 8 virtual cores (CPU at 33%, bad).
My guess is some energy saving option hidden somewhere, but I tried to turn off all of those both in BIOS and in Windows. And I guess there is some potential fix for this from the application side as well...

Have you tried setting CPU priority on the process itself to high? That should give it priority over other stuff when minimized.