42 bits?

Simone Bordet simone.bordet at gmail.com
Fri Mar 15 09:43:38 UTC 2019


while researching about ZGC, I could not find an authoritative source
that says that Intel CPUs are limited to 42 bits for addressing
memory, and therefore ZGC uses bits 0-41 for addressing, 42-45 for

OTOH, I found that there is a somewhat agreement in the search results
I found (e.g. https://en.wikipedia.org/wiki/X86-64) that 48 bits are
used for addressing memory.

Just curious. Thanks for shedding some light on this.

Simone Bordet
Finally, no matter how good the architecture and design are,
to deliver bug-free software with optimal performance and reliability,
the implementation technique must be flawless.   Victoria Livschitz

More information about the zgc-dev mailing list