Every angle in your system will reduce the performance, a 90 degree more as a 45 degree.
But the AS XT has enough power to produce the flow you will need to cool your system.

Hi logitrust,

I found an german article about the influence of 45° or 90° angle fittings and diameters of the tube regarding the flow.

The pictures are selfexplaining : http://www.aquainfos.net/2009/10/26/durc…vergleichstest/

The author found:

a) there is a big influence between 8/6 and 13/10 tubes, 16/13 slightly smaller flow (in the compared system: 220 l/h; 280 l/h; 278 l/h)
b) in a system with 13/10 tube there is a slight decrease in flow by increasing number of 90° angele fittings (10 straight fittings:280l/h; 10 straight fittings + 2*90° fittings: ~270l/h; 10 straight fittings + 6*90° fittings: ~250l/h, 8 straight fittings + 2*90° fittings: ~270l/h, 4 straight fittings + 6*90° fittings: ~240l/h => so every couple about 10 l/h less flow - it seems that a straight fittings have no influence)
c) in a system with 13/10 tube there is a stonger decrease in flow by increasing number of 45° angele fittings (6 straight fittings + 4*45° fittings: ~200l/h) . The author found the reason also: there are steps inside the fitting which reduce the diameter.
d) between 280 l/h and 250 l/h there is only a small difference in CPU/GPU temperature (~0.5°C).

I found more articles regarding this issue. I think this article and the data give a good impression.
That is the reason why I will switch to 13/10 tubes and compare this with my actual system.
I hope this helps a little bit.

cu