Something not mentioned there is locking. For the specific use case (timestamps) that the OP wants, it might not be important, but for many common use cases, like 64 bit counters, you can suddenly hit consistency problems in programs. I think that older x86 processors couldn&#x27;t atomically write 64 bit numbers, so you might have to add locks around all the accesses. This could be a huge performance hit.<p>ISTR this was a problem for Linux kernels? There used to be several kernel counters that were stuck at 32 bits because the overhead of making them 64 bits was just too much. I think one example was network byte counters for NICs? I might be misremembering this, though.