I'm not familiar with Git internals. Does the performance of the hashing algorithm contribute significantly to how Git deals with large files or with operations

I'm not familiar with Git internals. Does the performance of the hashing algorithm contribute significantly to how Git deals with large files or with operations over a large number of small files? I've run into performance problems with things like MathJaX, which includes thousands (or tens of thousands?) of files as a backup method for rendering equations. (I understand each file has a single character in some typeface.)