Results of latency test, list of computers tested for use with LinuxCNC

Tried it without the base period, board with J1800: 

 

In any case on the same hardware latency is many times more than on 2.8.4.

Also tried it on an old desktop, E8200, 2GB of memory (one slot on the board doesn't work for some reason), video Radeon HD5450 512Mb:

 

And without GPU:

 

And now I have a dilemma: to use these mini-itx boards with large latency or to put mesa everywhere (but it happens better to use LPT for simple machines). Or look for desktop hardware, but it is not always convenient to place it.

Mesa is great, lots of io, very well supported and reliable.
Pete’s support is out of this world, even to the extent of answering questions regarding running Mesa firmware on Spartan 6 development boards.
Plus it takes the frustration out of latency issues.
Regarding desktops, I have a Lenovo M72e, mini tower, that I found on the street curb, $20 for an quad core I5 and it has awesome latency. Word of warning tho, whilst it does have an on board Parallel port header it does require a genuine Lenovo parallel port cable to work. Tried a standard one and no luck. Haven’t done any reverse engineering of it.

For parallel port use the Buster official ISO and install the RTAI kernel as described in the downloads page.
For mesa, use the 2.9.1 ISO or install Debian 12 BookWorm and do
sudo apt update
sudo apt install linuxcnc-uspace
reboot and enjoy.

Cant do this anymore bye all wrote:

Word of warning tho, whilst it does have an on board Parallel port header it does require a genuine Lenovo parallel port cable to work. Tried a standard one and no luck. Haven’t done any reverse engineering of it.

Normal or mini header?
For normal header with normal DB25 port/cable, the side with the red line on the wire goes on the pin1 side of the header. Be aware that some DB25 adapters/cables have that backwards, so inserting it in reverse bares no risk and might work.

Using a normal 0.1" header the parallel port options aren't shown in the BIOS setup. Use the Lenovo one and they show up. I'm guessing that one of the GND pins or pin 26 is connected to a GPIO on the incarnation of the Super IO chip. I know that for the serial port header there is a COM_DETECT pin, so the same kind of thing is at play with the Parallel I guess.

Like I said I didn't decide to pull the thing apart to find out what was going on.

Seems to be pin 18 on the header is the PR_DET# pin.

Asus Prime J4005I-C
Turbo boost enabled
C states disabled
Command line: idle=poll mitigations=off cpufreq.default_governor=performance 

is this good? 

There is no latency data in the file you attached @CNC_Andi

"Debian GNU/Linux 12 (bookworm)"...
Latency testing loop started Mon Dec 11 01:13:08 PM CET 2023,
should end after Mon Dec 11 03:13:08 PM CET 2023

Manual termination requested at 11.12.2023 13:23:52

@CNC_Andi:

• As you are on bookworm, there are chances the script does not run properl on bookworm. I *think* it should do alright though, but I'll have to verify that. => Todo for myself
• Delta t "Mon Dec 11 01:13:08 PM" (=13:13:08) to "11.12.2023 13:23:52 " is about 10 minutes only
• As tommy pointed out: there is no latency data. Do you have a .lat file? if so, kindly post it

Greez
chris

Oh sorry.... wrong file...

Yes i run it at bookworm...

I will upload the other file later.