Code:
memory (kbytes) 32632104
32GB. 8 GB for each of the 4 cores of an AMD II X4 965.
As to your apparent 5GB limit, I would look to determine how much virtual memory is available between available RAM and swap, as the allocations must come from somewhere. Once you have confirmed that physical memory and swap space are not the reason for the limit, I recommend reaching out via Email. You should contact either Brad Smith, who is the port maintainer for emulators/qemu, or more generally ask the larger OpenBSD community on the ports@ OpenBSD mailing list.
Unfortunately, this forum is relatively small and no one else has chimed in with any assistance.
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(When I was doing Android builds, I used an Asus notebook with a 32-bit only Atom CPU and 1GB of RAM. Are you sure you need so many GB of memory?)