bad idea, two pumps parallel with y-fittings

, if one pumpe fails, all the water will go through this one, and wont be available for cooling the chips.
use them in an row, then you also get more pressure, and with that the more power you want
and if one pump fails, the water will still flow in the system
oh, before i forget, i would wonder if an eheim will ever fail

if they once work, they're unbreakable ;D