How does Roon calculate CPU load for upsampling or other processing?

Core Machine (Operating system/System info/Roon build number)

DIY PC with Core i5 9600K, 16GB RAM, NVMe for OS

Network Details (Including networking gear model/manufacturer and if on WiFi/Ethernet)

HP Procurve and TP Link switches, all gigabit

Audio Devices (Specify what device you’re using and its connection type - USB/HDMI/etc.)

Roopiee on Pi4 4GB to Topping D90 MQA USB

Description Of Issue

Not sure whether this is an appropriate section but here goes - how does Roon calculate my CPU load when upsampling?

When upsampling to DSD512 on an older LGA1366 Xeon machine the processing speed drops below 1.0x and dropouts occur while the CPU load on the cores is only roughly 30-40% (parallel processing enabled). Why doesn’t it utilize the cores to, let’s say 60-70% to maintain stable playback?

Also, shouldn’t upsampling (in the end, a heavy load) trigger the CPU’s max boost clock? I was surprised to see that even my i5 was downlocking instead of using it’s full power, unless I set the power plan to “High Performance”.

Hi @Martin_J,

We provide information regarding this in our DSP Engine Documentation:

I have copied the relevant parts below:

Pay attention to CPU Usage

Some of the features in the DSP Engine can consume a lot of CPU resources. Nothing beats a nice beefy Core i7 if you want to turn everything up to 11. If you’re running on a weaker system, particularly one that is shy of our recommendations, modulate your expectations accordingly.

Use the processing speed indicator to get a sense of how “close to the line” you are. Numbers below 1.0 mean that the CPU on your Roon core is not powerful enough to execute the configuration you’ve requested. This is about as close to peril as you want to be

Note that Roon currently runs the DSP engine on one CPU core per zone–so this reflects the load relative to consuming a full core. “2.0x” means you’re using 50% of one CPU core to play music in this zone.

Hope this helps!