To be honest, the power wires for the CR is way over kill. The wire supplied is 22 awg which is good for 5 - 7 amps. There is no way in hell that small chip draws that much current. The max current on the 5v side of a 203w power supply is 1 amp so the 3.3v is probably going to be around there or less (this is just my guess but still). If I was to guess, I would say that the CR will draw around 50 ma (milliamps) or so in which almost any wire will handle just fine but it can't hurt to double up the wires.
I'm getting ready to install another one of these and I will be sure to measure the power draw just to satisfy my own curiosity.
http://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity
edit:
I just found this for the Xilinx chip. I don't know if it is the exact same one used on the TX CR but it's going to be close. It says:
"Fast Zero Power (FZP) design technique provides ultra-low power and very high speed
- Typical Standby Current of 17 to 18 μA at 25°C" (1,000,000 microAmps (uA) = 1Amp (A))