I've installed obsd 5.3 amd64 (generic.mp) on a AMD II X4 965 processor
I can start qemu with up to 5G memory now then it throws unable to allocate memory error.
Code:
$ulimit -a
time(cpu-seconds) unlimited
file(blocks) unlimited
coredump(blocks) unlimited
data(kbytes) 8388608
stack(kbytes) 4096
lockedmem(kbytes) 10878357
memory (kbytes) 32632104
nofiles(descriptors) 512
processes 1310
$ulimit
unlimited
I'm building android platform source so 16G+ memory would be preferred. If I can build android directly on obsd instead of using qemu after tinkering I'll let everybody know, that would be great success.