Latency high with 10.04 but OK on 8.04

I tried to update EMC2 to 10.04 on my CNC system (stepper driven Shoptask). Like a ninny, I didn't check the latency with the live CD before I installed it. Once I got it installed the latency was terrible. I tried a few things different in the BIOS and the like, but nothing I tried made any difference. I am using a USB wireless dongle. I tried disconnecting that. I could find nothing that would get the latency back to what it was on 8.04.

Any ideas of what to do next?

Thanks for the help,

Gridley

Hello Gridley,

This does not answer your question but I have had similar results. My latency was off the wall!
I went back to 8.04 because of this. I wonder if the fact that 10.04 uses GRUB2 instead of GRUB and seems to handle video different might have something to do with it. The problem has come up before on the forum but I have not seen a solution.
The opposite may also be true that some newer computers will work with 10.04 but not with 8.04

Rick G

Hi

i too have had this problem, i found it to be down to the motherboard chipset, i am running intel setup
MotherBoard : gigabtye - ga-p35-s3g
North Bridge: Intel P35 Express Chipset
South Bridge: Intel ICH9


the ICH8 does not seem to have a SPI option in kernel.
it seemed fine for about a min on loadup, but then there is a nasty spike every minute or so i found...

this motherboard i found to work quite well. both under the same CPU, graphics etc..
Motherboard : gigabyte - ga-ep41-ud3l
North Bridge: Intel G41 Express Chipset
South Bridge: Intel ICH7

this one also i found laying around to try out

Asus P5P41D
Chipset Intel G41 ICH7

also AMD seems to work quite well too i found on 10.04

Hi

I'm too a bit suspiciuos of my 10.4 installtion.

I know the latency test program....

Is there a way to find what is "generating" the latency, means does somebody can give a hint where and how to search the system for the bottle neck ?

Thx Mike

try running the realtime test from witin the kernel tools folder,

in terminal go to
/usr/realtime-2.6.32-122-rtai/testsuite/kern/latency

then run
./run

let it run for a while any overruns is a very bad thing for realtime.
the other colums should show you a good overview of the system.. SMI shows up as peaks in the numbers every will milli seconds or so.. you can try turn this off at your own risk see Wiki

if its a constant problem then things get abit more tricky , try swopping graphics card, changing bios settings etc

hope it gets you started some where..
rob

THX

I'll do that, it's not to bad, my PC is acceptabel, only on startup I get a time related error message,
but my "stomage" tells me I should have smaller latency.
And as I want to swapp this PC to my productive machine, I want to be sure to get an aprovement !!

THX

Yes John

thats what I'm guessing too , after reading the message.

I like 10.4 but I fear on my older 1,6GB Atthlon, it has some "issues"

I'll dig into it over the next days, I'm short in time ....