Better: Solidworks Premium 2015 Portable X64

is a proprietary commercial computer-aided design (CAD) software developed by Dassault Systèmes. There is no legitimate "portable" version of SolidWorks created or authorized by the software developer. Any website offering a "portable x64" version of SolidWorks 2015 is almost certainly distributing:

Whether you are looking to maintain legacy workflows or simply curious about the evolution of CAD tools, here is what made the 2015 x64 Portable release distinct. SolidWorks Premium 2015 Portable X64

SolidWorks 2015 introduced several performance-focused features designed to speed up the design process. The Premium edition includes the full suite of CAD tools: SolidWorks Premium 2015 Portable X64