We report an experimental study of the carrier transport in [1 1 0]-oriented long channel tri-gate (Omega G) and omega-gate (SIG) silicon nanowire (SiNW) transistors cross-section down to 11 nm x 10 nm. Electron and hole mobilities have been measured down to 20 K to evaluate the contribution from the dominant scattering mechanisms. We have studied and discussed the influence of channel shape, channel width and strain effect on carrier mobility. In particular, we have shown that the transport properties are mainly driven by the relative contribution of the different inversion surfaces, without noticeable differences between TG and Omega GNWs. We have also demonstrated the effectiveness of an additional uniaxial tensile strain in NMOS NWs down to 10 nm width. (C) 2013 Elsevier Ltd. All rights reserved.