AMD Opteron SVDC DFM1
An unknown S940 CPU. It probably fits in the category 'Opteron' and it might be a very early sample or a mechanical or thermal sample.
My sample has the markings 'SVDC DFM1' with 2050, 25.5 and B2 in the corners. With red there is a faint shade of what used to be the number 141. I've seen another sample that has 144 in red, and 3.6 in the left lower corner instead of 25.5.
I've tested this CPU in my MSI K8D Master-F engineering sample motherboard with BIOS v1.0 but it doesn't boot up. The beeper gives a generic alarm noise which you also get when there is no CPU, or no RAM, or RAM in the incorrect slots. I've tried different kinds of memory, even non ECC Registered, but to no avail.
On the positive side: nothing burned up and nothing shorted out. Perhaps the CPU is really working but not with my motherboard. My early Athlon 64 sample only works in an AMD Solo motherboard and not in general S754 production boards.