I wonder if i would use SPI and send data to control this all what would be the shortest time to send such control information ?.
Yes it would. No other interface is faster.
If i am right, then SPI is a kind of cable on which multiple (arduino?) devices can connect and each get a number.
No, that is describing I2C. SPI, each device (or string of devices) gets its own chip select (aka slave select).
SPI is the fastest interface, with default clock rate speed of 4 MHz - fastest I2C speed is 400KHz, and requires the devices to acknowledge the transmission.
Here's what I was discussing earlier. This is drawn with open-drain TPIC6B595, replace with 74HC595 if don't need the higher current sink capability.
The board pictured can hold 12 TPIC6B595s, I have daisy chained 2 of them with 20 shift registers total to control a 5x20 display (used 5 of 8 outputs on each).
Apparently I can't count all the time - 256/8 = 32 chips, so 4 strings of 8, could that with 4 of these boards. Only 1 needs the uC setup, the others can be just shift registers, caps, and connectors.
