Doesn't matter too much because the cables are manufactured and tested according to standards. However, I understand your doubts and at that time I also bought a special cable:
Lindy GOLD DisplayPort Cable (2m, Premium, Black).
You can test the supplied cable and then buy the cable. I am very satisfied with the cable, but it is quite inflexible due to all the shielding layers.
I can make another recommendation when I know what your price expectations are.
