Thank you very much! I found bios 5.3 on Internet Archive, just not the tools.
I have DG6 board already with OCNG 5.3 bios, 2x Opteron 6328. I might replace it with 2x Opteron 6380 to get 32 cores instead of 16 cores despite lower base CPU frequency.
Even without overclock, it outperforms my...