Hi ! You may want a 32 bit board for your 3D printer:

• cool features: network, available nice lcd/tft screen
• more memory and higher speed enabling fast speed on Delta and other kind of bots
• quieter to run due to improvements on the stepper drivers, speed, frequency...
• better cooling for stepper drivers when there is a large PCB

So far there are not a lot of 32 bit boards on the market, probably I miss a few of them, if you see a missing one, please poke me, I will update the post.

SmoothieBoard Based

SmoothieBoard

http://smoothieware.org/smoothieboard
It has a good reputation running its own firmware Smoothieware, it is a relatively large board which is good for temperature management, it has a network interface and several IOs. From stepper drivers point of view nothing fancy they work correctly and there are digit pots so you do not have to mess up to manage the amount of current needed. The price is quiet high 150 $ (and even higher in Europe: 180 €).

Re-Arm

The Re-ARM which is a RAMPS style based on the same CPU as the SmoothieBoard: https://www.panucatt.com/Re_ARM_for_RAMPS_p/ra1768.htm. You will need a RAMPS board that handle correctly 3.3V with level shifters for 5V and other stuff. 45 $ for the board and after you need an adequate RAMPS board.

Azteeg Family

The Azteeg X5 mini wifi which is based on the same CPU too: http://www.panucatt.com/azteeg_X5_mini_reprap_3d_printer_controller_p/ax5mini.htm. A nice compact card for 113$.
The Azteeg X5 gt is interesting too: http://www.panucatt.com/azteeg_X5_GT_reprap_3d_printer_controller_p/ax5gt.htm. About 110$ without stepper drivers and without LAN.

MKS SBASE

The MKS SBASE is probably the cheapest available with DRV8825 (100 Khz frequency), LAN and the same CPU as the SmoothieBoard. About 50$.

Arduino Due Based

RAMPS-FD

It is an Arduino Due and a RAMPS-FD board, it is affordable, you need to be careful to select well the RAMPS-FD.

Archim

The Archim is an Arduino Due based board made by UltiMachine. https://ultimachine.com/products/archim-1-0a?variant=40860520842. It is expensive too with 150$ and only DRV8825 drivers while the small Einsy with the desired TMC2130 drivers retails for 110$.

Duet

Probably the best technically is the Duet: https://www.duet3d.com/DuetEthernet
Allowing high current and super quiet stepper drivers. There is also an expansion board allowing you to drive up to 7 extruders. The price of this beast is about 180$. It comes with its own firmware.

Firmware support

Smoothieware officially only supports the SmoothieBoard and boards compliant with their opensource license, there is a war with MKS with its SBASE.

Marlin 2.0 32-bit supported boards: https://github.com/MarlinFirmware/Marlin/issues/7076
The HAL will give an hint of what is "supported" or going to be supported: https://github.com/MarlinFirmware/Marlin/tree/bugfix-2.0.x/Marlin/src/HAL
There are a few STM32 based controllers that start to be supported, but I did not see any interesting board for the moment.

Repetier supports mostly Arduino Due boards: https://github.com/repetier/Repetier-Firmware/tree/master/src

Questions

• Do you plan to move to a 32 bit board ? Why ?
• Have you already moved to a 32 bit board ? Pros ? Cons ?