Intel D525MW - high jitter

Hello, after reading posts about Intel D525MW I believe that buying this board was good idea:-)
However, in my case measured jitter is too high - base thread over 130 000 ns (2 glxgears running for 4 hours).
In BIOS I disabled Hyper-Threading and unnecessary devices (onboard LAN, audio). I also applied isolcpus setting but it didn't help much.

Please advice me how to tweak it.

Thank you,
Kamil

The D525 has not been available for a couple of years with the big stockists.

What did you install on it?

All the testing will have been done with the Ubuntu 10.04 based distro.

In BIOS I disabled Hyper-Threading and unnecessary devices (onboard LAN, audio). I also applied isolcpus setting but it didn't help much.

You need to disable the power management, but so long since I looked, had to boot mine.

First page disable Hyperthreading
In the Boot menu disable system fan and set it to 100%. That gives max cooling (if there is a fan) without it needing to check the temperature. Adjust accordingly if you are in Arctic circle!
In Peripherals , disable Audio and Serial
Disable event logging
Use isolcpus=1 in the boot line

When I had the Ubuntu distro installed on it I tested it at about 10 - 12K, but I just use it as a media server and have standard Wheezy on it now.

Hopefully that might help, the big one is probably to try Ubuntu if that is not what you installed.

regards

PS

Forgot - in power management
Set ACPI to S1 and disable all the other suspend and wake options that you can

Thank you! I will check it on the weekend and will let you know about results

Today I finally got to install Ubuntu 10.04 on my D525MW and indeed results are better. After one hour of running 5 glxgears and browsing pdf file max jitter is about 20k. However I ran system monitor and noticed that both cpu cores are busy, although I edited /etc/default/grub and added isolcpus=1 parameter into GRUB_CMDLINE_LINUX_DEFAULT.
BIOS setting are set as you instructed. Is it normal behavior?

.... although I edited /etc/default/grub and added isolcpus=1 parameter into GRUB_CMDLINE_LINUX_DEFAULT.

Did you run update-grub afterwards and does it show up on the kernel boot line in GRUB?

I forgot about it, thank you. I just ran another latency test and will share results later.

After 16 hours of running multiple glxgears, system monitor and top command, maximum jitter equals ~ 32k. Is there another way of decreasing this value?
System is installed on a pendrive, can this is be a cause of problem?

System is installed on a pendrive, can this is be a cause of problem?

It certainly won't help

Use the rtai latency test as outlined in my FAQ
www.linuxcnc.org/index.php/english/forum...-the-latency-problem

Then you will be able to see when the spikes occur

The other test is a cumulative one and gives no idea when a spike occurred or what the underlying figure is.

If you had one high spike on drive access through USB, it would continue showing that figure for ever more

regards

When tried to execute /usr/realtime-2.6.32-122-rtai/testsuite/user/latency/run I got an error rtai-load: cannot find run info: /home/jacoren/.runinfo