Latency spikes

Hi,
i have a P4 2,5 gb, 1gb ram chipset intel (82801EB/ER), ati radeon with linuxcnc installed.
Latency test is about 4000/6000 very good and with parallel card all work fine.

My problem is that sometimes latency goes to 240000! In this moment all stucks.

I tried to change graphic drive from "radeon" to "vesa" or "fbdev" but the problem is the same.

this happen also if i don't use keybord or mouse, random i have latency >200000.

May be SMI?
I read in the FAQ that SMI for 82801 EB/ER is not a problem.

any suggestions?

Thanks.

Hi

I have the 2 P4 machines in question and there is no SMI problem with that chip I know of and there is no SMI listing in the smi code for that chip either

Try the latency test as outlined in
www.linuxcnc.org/index.php/english/compo...ew&catid=18&id=19022

This should help pinpoint when the spikes occur. SMI will normally be 32 or 64 seconds apart and very regular irrespective of whatever else is happening.

regards

Thank,
with this tool the latency seems to be constant at 7190. Now is active fbdev driver.
I stopped many services like bluetooth.

I'll test the system in the next days.

regards.

Co-incidentally I bought in another of the same Fujitsu-Siemens P4 2.4GHz computers a few days ago

It has the same chipset (82801EB/ER) and I set BIOS the same way, completely disabling APM, setting the fan to max so that it doesn't keep checking temp, disabling hyper-threading etc
The video chipset is the same (Intel 82865G video chipset) so I was expecting the same figures as the other 2 I have.

When I ran a latency-test it was initially 5500 ish and then spiked to well over 200,000 as soon as I touched the mouse (that may well have been co-incidence) and kept spiking at a period of only a few seconds.

The old computer I was going to replace, runs unloaded at 5995 and even with quite brutal loading never got above 9500.

I have stripped the new one, upgraded all the peripherals on the old one and given it the new case etc. and the new computer will be doing house duty.
When I get time I will try to fathom out what is causing the spikes, which may assist.

In the interim I am tempted to remove this computer from the 'known good' list - I put it there so suppose I am entitled!

regards

PS
Installed 8.04 and ran a latency test for 5 hours on this machine with different memory sticks, HDD, keyboard, mouse, VDU
It ran on 10,553 for 3 hours or more and then had a single spike which sent it to 29000 ish
Very strange - it is not SMI thats all I can say for now

Had it stayed on 10553 I would have been tempted to blame mismatched memory modules for the first set of figures.