The pic im using is a PIC18LF46K22 and it does have an MSSP module. Just a question on using the MSSP in terms of speed, are we talking 2x 3x 4x speed increase. I can currently completely fill the screen in less than a second.
Hi, it's my understanding that SHIFTOUT runs at 50kHz with a 4MHz oscillator and then scales linearly with increased oscillator speed, but I'm not 100% sure on that. The MSSP module can run at Fosc/4 which at 4Mhz is 20 times faster than SHIFTOUT.

Now, the code must be able to keep up with the increased speed, and must be able to feed the MSSP module with data to shift out. Basically you have only 8 instructioncyles to get the next byte and then load it to the MSSP module as soon as there's room in its output register. If you're not able to do it in 8 cycles the overall thruput will drop - obviously.

So, just because the "clock" runs 20times fater than SHIFTOUT I don't think you should expect a 20 times increase, somewhere around 5-10 sounds more realistic.

/Henrik.