I know - we don't need to sample at 192 kHz and I don't but I did test my new AES16e card in several scenarios to see if I could achieve low latency. The answer is yes although not a low as Lynx states.
 
What did surprise me is the hit Sonar takes at 192 kHz - about 50% of the 4 core processor at 2.8 GHz. That almost looks like a bug or something since the 172.4 kHz is under 5%.
 
Anyone have any ideas on why it jumps to such a high utilization? Thanks.
 

Don't know about whether that's appropriate (depends on complexity of track/effects/vsts) but you WILL take a huge cpu hit running at higher rates... This has nothing to do with Sonar.
 
I ran at 96 for awhile as my Forte driver latency kinda sucks  but went back to 44 as cpu hit, even with my 6 cores, was too heavy.  
 
It's why my NEXT interface will be an RME... extremely low latency at 44 without having to jump to higher sample rates.
 
You might wanna post this in the Studio Hardware section where folks talk about this stuff and the experts who build daws/track this stuff hang out.
 

Don't forget that you're moving a heap more audio data with a higher sampling rate. This will tax your hard drive if it's not up to the job.

im hoping your PC is of the newer kind. 192K is like driving 150 MPH in a Go Kart.
It going to be fun but something is going to give sooner or later
 

Was this without any plugins?

We often digitaze vinyl for customers with 192/24 and we do this with an 150$ cheap AMD computer Dual-Core 2.8 GHz. Recording one track the CPU goes to 28%. RME Fireface 800. Audio recording into a network device (NAS-Server).

while we all agree that higher resolution means more cpu, the pertinent question is why such a big leap, from 5% @ 172 to 50% @ 192 - the cpu increase is not proportionate to the resolution increase

You should definitely test it without any plugins first. There shouldn't be a big jump from SONAR's point of view. However plugins might internally downsample to their native sample rate which could cause a hit.

mudgel
Don't forget that you're moving a heap more audio data with a higher sampling rate. This will tax your hard drive if it's not up to the job.

The weird thing is that 174.2 kHz uses like no CPU (5-7%) and the moment I upped it to 192 kHz it was 45-60%. That can't be justified by data since there would only be 10% more data being processed.
 
This was only 2 tracks of keyboard demo with no processing.

The test audio is two tracks 2:36 long, no plugins or native effects or ProChannel.
The test was recorded using a Lynx AES16e audio card @192 kHz.
There is something going on with Sonar because it has audio engine failures.