MoTeC Global Forum

ECU CPU Usage.

One for the Technical guys.

We're running M800's at between 96 and 100% CPU usage.

Is this detrimental to performance?
If so which areas will suffer first?

If I look to change my setup to get the CPU usage down, which areas use most CPU?

Basic setup,
M800,
ADL2,
DBW4.
4 cyl 8 injector COP

No one from Aus can answer this?

Melbourne Aus?

I'm from Melbourne but I can't answer it

I can however say I noticed the same thing when I ran my DBW4 so am curious to hear an answer, I'm back on ECU/DBW now and will check CPU usage next time I run the car.

Martin wrote:Melbourne Aus?

More specificically...merrindale drive

Martin wrote:

Martin wrote:Melbourne Aus?

More specificically...merrindale drive

I could drive over there but I still wouldn't know the answer

When CPU usage gets too high functions will be shut down in order of priority with vital engine functions being maintained. Usually the first thing you would notice as you hit the limit of CPU usage is unsual data in your log files as the logging is a low priority function. What you would see is data that looks like it has been corrupted. You would also see a slowing down of the CAN data transmission speed.

As far as what contributes the most to CPU usage this is a bit more complex and is dependant on a lot of variables. The first thing I would do is look through your configuration and disable any un-used tables and/or table axis.

Thanks Ross, where would be a safe point that below the ECU isn't dropping data?
(have noticed the logging issues in the past)

Many thanks Ross.

I have seen the logging problem.
Is the CAN data speed going to slow down the response of the DBW4?

Your DBW should be ok, I was referring to CAN data to things like ADT etc.