Yes your Pc should be faster.
As for "load":
Games will go from SSD to memory etc. faster.
Should help with download speeds as well provided there are no other bottlenecks involved. I.e., ISP speed, network speed.
Performance is determined by the slowest component involved.
Be sure that your system meets, and hopefully, exceeds the installation requirements/specifications for the WD Blue 3D NAND SSD.