Latency to run 7i76E

What kind of latency numbers is a minimum to run 7i76E?

AC servos with Step/Dir control.

Cheers
Bengt

I've seen PCW quote that hes had machines running fine with 120 usec latency. (USFF PC)

Hi Rod,

is that base thread numbers?

We don't use a base thread on the 7i76e, only a servo thread so ignore base thread latency. PCW would have been quoting servo thread.

OK, that means my PC:s are waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaay to slow or ??


Have to find new MOBO's that fit mini-ITX or close to that size as I have lack of space.

Any suggestions to what to buy?

Ouch!

This is what I'm using with Linux Mint 18.3.
www.gigabyte.com/Mini-PcBarebone/GB-BXBT-1900-rev-10#ov

Latency for a few minutes while writing this.....

I've also got the same PC in a N3160 which is the next iteration of the J1900 chipset and it works fine.
PCW linked to a Zotac Dual NIC PC which I could not source in Australia. if i bought another PC, I would probably get a dual NIC J1900 one like this on aliexpress This looks suspiciously like the one CandCNC's Command CNC uses (which is LinuxCNC based)

Remember it is mandatory to discard the internal Wifi cards and use a USB wifi dongle. If you don't your latency will worse than what you have now.

This is the thread I based my selection on. Some of the links have gone
forum.linuxcnc.org/38-general-linuxcnc-q...ff-pc-s?limitstart=0

Search for USFF on the forum, you might find a bit more info

tecno wrote:

OK, that means my PC:s are waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaay to slow or ??

Have to find new MOBO's that fit mini-ITX or close to that size as I have lack of space.

Any suggestions to what to buy?

Before you give up.
Have you tried any thing to improve the latency of the PC you have? Turning off power saving in the bios, hyperthreading, C states...
Have you tried different settings for ISOLCPUS? What MB do you have now?

www.jetwaycomputer.com/NC91.html

Tried everything possible in BIOS, ACPI must be enabled otherwise very bad latency numbers.

Also you need to run the latency test with the base thread disabled

(your latency numbers are meaningless since you have a base thread running faster than the CPU can service it)

For the latency test run:

latency-test 1ms 1ms

For the latency histogram, run:

latency-histogram --nobase