new build opinions required

[JAZZCNC]

-With servos: If Mach 3 outputs as max 100kHz pulse/ even less normally/, then why should i care to buy a board like the CSMIO or other? I know, apart from the reliability and connections, i mean. Every modern servo drive can upscale by gearing the frequency and generate the proper signal , so why waste money on expensive cards that will do exactly the same thing in fact? I start to believe that the driver generating the pulses will be quite better and reliable..
It seems that mach3 is the limiting factor, not the board?

Mach3 is only the limiting factor when using the parallel port and even then it's Not really Mach3 it's the Parallel port and it's driver.
When you use an external motion control card all these restrictions are taken away and infact Mach3 does very little other than watch I/O's and this is why low spec PC and Laptops can be used.

Now with servo's the freqency rate becomes important because the encoders and depending on the encoder count will depend on if you need higher than 100Khz. Which for most servos you will with out using the electronic gearing feature built into the drives.
Most who are using servos avoid electronic gearing because it lowers resolution and often the whole point of servo's and encoders is to give high resolution.

Now lets say you are using typical servo's with quadrature encoders having 2500cpr this means you need 10,000 pulses per rev so divideing the controler Pulse rate (IE: KHZ) by this amount gives Pulses per sec then times x 60 will determine the maximum speed you'll get from the Servo's. . .IE: 100Khz / 10,000ppr=10pps x 60s=600RPM

So has you can see 100Khz won't be much good if have 3000rpm servos has the fastest speed you'll get is 600rpm.!!

Now if the drives have electronic gearing multiplier then you can use this at the expense of resolution. So when 4x multiplier is applied then for every 1 pulse Mach3 controller sends out the drive will see it has 4 so 100Khz becomes 400Khz but the resolution is divided by 4.!!
400khz/10,000x60=2400Rpm better but still not enough so you'll need to use the nearest or above to give the 500Khz you'll need for 3000rpm with 2500CPR encoders.!!
Electronic gearing can be ok for some machines because the resolution will be very high to start with.!!

The next problem comes from the BOBs if used and it's Max pulse rate causing a bottle neck and yep most typical BOB's don't go that high so you'll need a very fast BOB and high quality BOB if your using servos with high pulse counts.
This is also why lots of High end motion control cards don't use BOB's so to speak (IE Csmio) and connect direct to any devices attached or thru dedicated daughter boards which don't cause a bottle neck.!

So be warned to all those dreaming of using servo's just be aware they take you to another all new level of head scratching and expense.!! . . . . . So I honestly suggest you ask your self do you Really Really Really need Servo's.??? . . . . . . . Oh and just be aware they are still not closed Loop with Mach3.!! . . . . . The best they can do is Fault if they see a following error.

For 99.9% of DIY machines and even relatively slower Light industrial machines steppers if spec'd and setup correctly are far far far less hassle and plenty accurate enough.