LRU vs FIFO page replacement
For anyone visiting this thread in the future, FIFO can have less page faults in some scenarios.

In this one ( &lt;2, 6, 5, 7, ..., ..., ...> ), it can be completed with 2, 8, 6.

The access of 2 means that the least recently used page is 6, but the first page in is still 2.

The access of 8 replaces 2 in FIFO, but 6 in LRU.

The access of 6, therefore, is a hit with FIFO, but a miss with LRU.