[slashdev]

I just want to add to your explanation, that even in the absence of hard paging from disk, you can have soft page faults where the kernel modifies the page table entries or assigns a memory page, or copies a copy on write page, etc.

In addition to the cache misses you mention there's also TLB misses.

Memory is not actually random access, locality matters a lot. SSDs reads, on the other hand, are much closer to random access, but much more expensive.