[erlang-questions] mnesia memory usage on 32 and 64 bits machines

Ulf Wiger <>
Sun Jan 2 14:08:33 CET 2011

On 31 Dec 2010, at 12:46, franz wrote:

> But does this mean that having a 64 bits kernel doubles the memory usage?!?

As a general rule, running with 64-bit Erlang doubles the memory footprint.
The exception is binaries, which use only marginally more space.

The OTP team is working on a "half-word" emulator, which uses a 32-bit 
memory space for the process heaps, but keeps other data (e.g. ETS and
binaries) in 64-bit space. This VM is still experimental, but can be built 
with configure --enable-halfword-emulator

Ulf W

Ulf Wiger, CTO, Erlang Solutions, Ltd.

More information about the erlang-questions mailing list