I'm using static build only so I can provide some data too. I compiled yesterday Boost 1.54 (from svn tag) with VS2012 Update 3. I compiled in both 32 and 64 bit. Build script: call bootstrap.bat call b2 --prefix=. --buid-type=complete toolset=msvc-10.0 architecture=x86 install call b2 --prefix=. --buid-type=complete --libdir=./lib/x64 toolset=msvc-10.0 architecture=x86 address-model=64 install 32 bit: libboost_log_setup-vc110-mt-1_54.lib 143,174 kb libboost_log_setup-vc110-mt-gd-1_54.lib 163,991 kb libboost_log-vc110-mt-1_54.lib 18,213 kb libboost_log-vc110-mt-gd-1_54.lib 61,590 kb 64 bit: libboost_log_setup-vc110-mt-1_54.lib 159,025 kb libboost_log_setup-vc110-mt-gd-1_54.lib 424,702 kb libboost_log-vc110-mt-1_54.lib 22,091 kb libboost_log-vc110-mt-gd-1_54.lib 75,565 kb However, in the application where I use boost.log, I have only one cpp file including a boost.log header (it setup the logging system then I provide my own logging functions to the rest of the system). That cpp file is part of a dll which is currently under 700kb (with boost.log statically linked). One other thing to note is that I define BOOST_LOG_USE_CHAR in that cpp before including log so it might help. All in all, I don't see the problem mentionned but because of my use I suspect that there might be a problem if you try to include some boost log headers in all cpp files, it might generate too much code. However I'm not sure at all of that. Maybe a basic test to check user binary growth when using only boost.log headers might provide more information. Joel Lamotte