[robobass]

I just upgraded from a maybe 15 year old computer to an Intel Core 2 Quad Q9400, 2.66 GHz, 6 MB L2 Cache, FSB 1333 MHz.
The Kernal speed is set to 35,000Hz from my old configuration. I'm not sure what that means, but everything seems in order. Would there be a reason for me to change it? It says that I have to retune my motors if I do.

[RCaffin]

You could probably increase the kernal speed to at least 100 kHz.
Yes, you should check the tuning of your motor servos - but they may not need changing.

Cheers
Roger

[CitizenOfDreams]

If your old setup worked fine at 35000, you should probably leave it where it was. A higher kernel speed will allow you to use a higher microstepping setting - if your machine needs it.

[dazp1976]

If you are using parallel port then leave it.
What it does is works out your max achievable velocity (pps) based on microstepping.
Lower kernel, higher micro = lower max vel.
Lower kernel, lower micro = higher max vel.
Higher kernel, lower micro = even higher max vel.
And so on.
However, parallel port can only do so much pps. Above 35000hz is when you start seeing unreliability regardless of the pc power itself.

The only way to get high kernel speeds is go with external motion controller.

[CitizenOfDreams]

P. S. If you are using the parallel port, your breakout/driver board has speed limitations as well. A typical Chinese board is unlikely to work reliably (if at all) at 100kHz.

[dazp1976]

P. S. If you are using the parallel port, your breakout/driver board has speed limitations as well. A typical Chinese board is unlikely to work reliably (if at all) at 100kHz.

True indeed.
Most cheap boards have basic optocouplers which have a speed limit.
Need to be either high speed units or not isolated at all.

[CitizenOfDreams]

Need to be either high speed units or not isolated at all.

I would recommend against the "not isolated" option unless you are prepared to treat your computers as consumables. Parallel ports are quite fragile.

[mactec54]

I just upgraded from a maybe 15 year old computer to an Intel Core 2 Quad Q9400, 2.66 GHz, 6 MB L2 Cache, FSB 1333 MHz.
The Kernal speed is set to 35,000Hz from my old configuration. I'm not sure what that means, but everything seems in order. Would there be a reason for me to change it? It says that I have to retune my motors if I do.

With that processor 45,000 to 65,000 Kernel setting would be a happy place for that computer, there is no need to change it if you have something like a UC100 which does all the processing at 100KHz for the computer, using something like the UC100 will make a big difference to your machines running