What constitutes 'high cpu' for SQL Server

Question

What level of CPU usage should be considered high for SQL Server? ie 80% 90% 100%?

Answer 1

It really depends on your machine. The best thing is to monitor the server using perfmon and see when things start to run slowly. It is normal for SQL to use a lot of CPU under load.

Answer 2

if under normal loads the CPU averages above 40% I start to get nervous. However, that's because I know the nature of our traffic and the spikes we get. Your mileage may vary.

Answer 3

Generally, you don't want a machine to sustain a constant CPU of over 40 or 50%, because it won't be able to handle spikes in activity.

Answer 4

We actually aim even lower, for about a 7-10% average, but we do sometimes get processing that will spike us to 60%.

We measure total CPU every 30 seconds and email a report daily, and if we see a move of 2% away from that average we expect for that day we investigate.

It takes time but it's helps me sleep better at night :)