With the advent of the Pentium processor parallelization finally became available to Intel based computer systems. One of the design principles of the MD4-family of hash functions (MD4, MD5, SHA-1, RIPEMD-160) is to be fast on the 32-bit Intel processors. This paper shows that carefully coded implementations of these hash functions are able to exploit the Pentium's superscalar architecture to its maximum e#ect: the performance with respect to execution on a non-parallel architecture increases by about 60%. This is an important result in view of the recent claims on the limited data bandwidth of these hash functions.