Geeetech GT2560: Electronic safety and power source I'm about to build myself a 3D-printer.

After a long search for a brain for this one I came across the GT2560 from Geeetech, because it leaves a solid impression on me.
The manufacturer himself has a quite extensive wiki page for this board. 

My idea now was to use an ATX power supply. 

The PSU is a be quiet! BN257. On 12&nbsp;V (combined) it can deliver 324&nbsp;W. On 12V1 there is 20&nbsp;A, on 12V2 16&nbsp;A.

Would that be enough or would you rather use a 24&nbsp;V power supply?

Since I have read some reports about the Anet A8 and its danger of overloading, I am a bit uncertain, even if the GT2560 looks a lot better than the A8.

Are the connections to which the heating bed and the extruder are connected sufficiently large to withstand 10&nbsp;A and 15&nbsp;A respectively, or should I solder the cables directly to the board from the very first?

According to the information I received from Dr. Search Engine, MOSFETs of type STB55NF06 are used. According to the data sheet, these can withstand loads up to 60&nbsp;V/55&nbsp;A. I don't necessarily need to replace them with external ones, do I?
Whether 350 Watt is enough depends on the amount of Ampere can be generated over the 12 V lines. Computer power supplies add up the power of all the voltages! A nameless or cheap 350 Watt PSU may not deliver enough power (in the sense that they may never reach the given power), you should check that out. The high-end PSU's are usually well fabricated and can usually deliver more power (but should not be taken for granted!).


a typical (214x214 mm) heatbed is about 12 V/1.5 Ω = 8 Amperes (about 100 Watt),
a typical hotend is about 40 Watt,
steppers and board could draw another 5 Amperes (about 60 Watt)


This totals to about 200 Watt, which your PSU should be able to generate without a problem.

Those green connectors plug in and out of the board don't they, usually with those small pins, transporting up to 10 Amperes is not recommended, you should look up the ratings of those connectors.