EMC Latency Test

Hello,

I am using Ubuntu installed inside Windows. My PC configuration is Intel CPU 1.6 GHz with 1.24 GB RAM, 2 GB free space on the drive on which Ubuntu is installed. When I run the EMC Latency Test, even without any extra load, the Max Jitter number it gives me is 704,795 for Servo thread and 728584 for Base thread. Even after having better configuration than the one required for EMC, what could be the reasons for getting such high latency numbers?


Regards,

Anshuman

During last few weeks I was playing with multiple computers and I realized that faster PC does not mean smaller jitter numbers

For example - I am geting excellent results with Inspiron 5000 P3 made in 1999, but it looks terrible with newer Dell Latitude D610 with 2 GB ram and fast video. I know laptops are not recomended, but does it apply to the older models? Does not look like.

I also installed it on P4 1.6A processor system and getting excellent results, but I can't get acceptable jitter on small fanless industriual pc I got.

I am about to get Atom 330 based board (Intel or Asus), but I am afraid I will get same jitter problems.
I am not sure how to handle this, I hope someone with better Ubuntu experience can give us some explanation

Hi,

I was going through the EMC2 Getting Started file and read about the SMI issues. I wonder if I am having this latency issue becasue of SMI. I have been trying to edit the "rtapi.conf" file according to "EMC Documentation Wiki FixingSMIIssues.htm" to disable the SMI. But the system said that I didn't have permissions even if I am the administrator. I have tried changing the file's permissions using 'chmod +w rtapi.conf' but haven't been able to do so either. How can I edit the file? I am not very familiar with Linux, so any pointers will be appreciated.

Andy, maybe you are also facing problems because of SMI. Do check it out.


Regards,

Anshuman

Hi,

I was hoping somebody would reply to this as I am not able to solve this issue. I need to edit the 'rtapi.conf' file so as to disable the SMI as explained in my previous post. But I am not able to edit the file or change it's permissions. I would appreciate any help in this regard.


Regards,

Anshuman

sudo sh

to switch root user account and then try again.

Hi acemi,

Thanks for replying. Using 'sudo sh' I was able to edit rtapi.conf file and was able to disable SMI. After that the latency test is showing me sane numbers.


Thanks again.


- Anshuman