  The colour fields created by the static tetraquark and pentaquark systems are
computed in quenched SU(3) lattice QCD, with gauge invariant lattice operators,
in a 24^3 x 48 lattice at beta=6.2. We generate our quenched configurations
with GPUs, and detail the respective benchmanrks in different SU(N) groups.
While at smaller distances the coulomb potential is expected to dominate, at
larger distances it is expected that fundamental flux tubes, similar to the
flux-tube between a quark and an antiquark, emerge and confine the quarks. In
order to minimize the potential the fundamental flux tubes should connect at
120o angles. We compute the square of the colour fields utilizing plaquettes,
and locate the static sources with generalized Wilson loops and with APE
smearing. The tetraquark system is well described by a double-Y-shaped
flux-tube, with two Steiner points, but when quark-antiquark pairs are close
enough the two junctions collapse and we have an X-shaped flux-tube, with one
Steiner point. The pentaquark system is well described by a three-Y-shaped
flux-tube where the three flux the junctions are Steiner points.
