getting started , latency and breakout board questions

Good afternoon.    Well after a few mis-starts,   I am pretty sure I have a good Linuxcnc 2.9.4 install with Debian 12,; on a old Lenovo Thinkcenter  with a core3 processor, and a single onboard parallel port and a 1Tb Solid state HD      I have run a latency test, and the results are not super great, and quite a bit worse today than yesterday.  (yesterday the servo thread was  69200, and the base thread was 32900).   Here is a photo from today; after i opened up some calculators and the video player with no video to play..    Is this going to be a non starter because of the latency?    This computer was a freebee,    i was going to try a old windows XP machine, and i found out last night that would not work regardless,   So this is what i have for now.    If this is going to be a non starter for latency  i would like to know sooner than later  I am just barely capable of basic Linux navigation with a bit of help from google.    I had older Linux version 3 years back that seemed a bit different, I am trying to learn the newer version.       I am not sure i am even testing correctly.   I am have the LinuxCnc on a boot thumbdrive.    and once the computer is booted,  i am starting the Latency test from the Applications menu topmost left screen.    Then the CNC tab, and then Latency test.    As far as i can tell this HAS NOT started the actual LinuxCnc program which i thought was the correct way to go?     If i just run the latency test and do not exercise the machine i get  servo at 9139, and Base thread at 19360     The computer as i said is a freebee.   My IT friend gave it too me and we changed the OS to Linux,   and we then got the LinuxCNC image burned to the thumb drive.          I am not savy enough to know ,   But If we just wiped out the old OS which i think we did,   can or is there still some junk maybe running or causing problems from the old windows OS  or the hard drive,   that can mess with the latency????     When I open LinuxCnc it opens to the configuration selector  ( good?),   But i don't think i am ready for anything else at this time;?   If the Latency can be solved,  then I believe i still need to pick a parallel port breakout board  Correct?     For the breakout board i have been looking at the c10G and C11G break out boards,    I am hoping for a bit of help picking the break out boardI have a few different applications in mind for LinuxCnc, but the first application will be a  3 Axis Lagun mill that used to have a Crusader M control.   the machine went under salt water up to the quill,   the  ball screws seem ok , and the head and quill still work,   but the old Crusader M control and the old DC servos are toast,        I wouild like to put new AC servos back on the mill,  and i have been leaning toward the ClearPath  servo with amp combo, and i wanted to keep to the parallel port for now.    So is the latency going to be a problem?   can it be fixed?   Should i just find another computer?thanks 

The latency will limit your maximum speed but not interfere with basic LinuxCNC operation.

Have you gone through the various latency improvement options:

Disable all speed switching/turbo modes in the BIOS

Disable any power management in the BIOS (C states > C1 etc)

Disable hyperthreading

Set isocpus-L in kernel command line (with grub)
(where L is the last processor so 3 for example with a 4 core machine)
 

thanks for the quick response.   NO i have been looking a bit for latency improvment,  but i did not get anywhere,   I am trying to get a actual AC servo to practice  with, and i am still looking at breakout boards,    AND wondering if it will just be easier to go with Mesa boards???

   i hate to say it but i am going to have to start from scratch with your suggestions,    But i am trying to search them now.   

Thanks 

After a bit of luck i have managed to access a menu that has the hyper threading setting.   In the pic  i have disabled the top 2 options.    How about the rest of the settings in this menu? 

  DO i need multi core processing??

Are these changes permanent or do I have to resett them every time i power cycle?

also i am double spacing these posts when i type, but when i submit the post ;   they get all squashed together.Is there a way to keep my double spacing so the post is easier to read? 

yes, you want multicore processing enabled

You should also disable Cstates > C1
 

i have disabled all the options in the above picture . the latency test is still early, but it looks much much better

OOPs   i read a snippet from somewhere that said it would be good to start on a single core and the add the cores if i need them?     

i disabled the C1E, but not the C1,   i did not see C1 as De-selectable,   I will try again 

i can change it back correct?

OK C state support is set to C1.

and multi core is RE-enabled

thanks very much for your help PCW.

i am re running latency test again,   i did not take a pick from a few minutes ago,  but i think the servo thread was under 10000, and the base thread was about 26000

 

thanks again for the help     this is what i have set up NOW,   exercised latency is as pictured,

Are there any Known problems with a C11G multifunction CNC board?    for AC servos?

thanks

thanks,   it does seem to be ok.    it will be a bit before i actually have some hardware to connect.    but i have been able to move the tool head around and PLAY the original linuxCnc gcode that traces LinuxCnc on the screen and the jog buttons are working.    

i will catch up when i get some hardware,   hopefully  within a couple of weeks.   I wanted to start with a technic clearpath all in one servo, for the quill

have a good night, and thanks

Thought I'd chime in, there's also the option of a CPU upgrade, did wonders for the ThinkCentre I found in the gutter.