I have a surface 4 pro 128GB and 4GB RAM m3 core is there any other difference between them
The major differences between an m3 and an i5 sp4 are the processor and the cooling systems.
The m3 has a passive cooling system (no fan) and a less powerful processor but has the advantage of being quieter and longer battery life. The i5 is a much more powerful processor but will use more battery and will be noisier when the fan comes on. The m3 is also cheaper. There are other differences as well. See this article for a comparison: http://www.notebookcheck.net/Face-Off-Microsoft-Surface-Pro-4-Core-i7-vs-Surface-Pro-4-Core-i5-vs-Surface-Pro-4-Core-m3.156031.0.html