Summary: The Opty 165 runs great in a typical non-server S939 motherboard. In this case, the Nagami2 board by ASUS - made for the COMPAQ SR1950NX PC. It has a large 1Mb cache for each core (largest available for S939 dual core cpu). This CPU is legendary for its overclocking capability (1.5X with stock heatsink, i.e. 2.5Ghz+). Although most S939 motherboards cannot fully utilize the 165 to its maximum potential, the 165 is still a superior CPU to the equivalent Athlon part.
Summary: I purchased my 165 from someone that was using it in a server, it came in perfect condition and is an awesome upgrade to the sad single core I was using. Originally I was going to build an new i5 gaming system but I thought I would see if I could upgrade to a dual core instead. I found out that my old 939 system allowed me to upgrade to the Opty dual cores so I started looking for an inexpensive model. I was very lucky to find my Opty 165 for $30 and immediate bought it.
Summary: It may not look like much out of the box, with its 1.8GHz stock frequency, but once you mount the Skt 939 Opteron 165 in a capable motherboard and overclock it, it's easily capable of running at speeds faster than the best that Skt 939 has to offer, the FX-60 (2.6GHz). Allied to an ASUS A8N32-SLI Deluxe, the Opteron 165 is easily capable of hitting circa 2.6GHz at stock voltage and using the stock heatsink-fan cooling unit.
Summary: This CPU so far has livied up to the hype. I have this chips currently with the asus a8n mother board running 310*9 = 2790 / HTTx3 running rock solid via 2x prim95's. The system is air cooled with my old heatsink XP-90 which never reaches over 40 degrees. If you plan to over clock this CPU is for you.
Summary: Great DualCore chip for any Socket 939 machine. Rated at 1.8Ghz can easily be clocked to 2Ghz or 2.1Ghz with stock cooler. Idles at 36C and loads at 42C. Easy to install using HSF counting clip and pre-applied termal paste. Runs on a Foxconn PCIe MicroATX board in an Antec Aria SFF case. Very pleased with this purchase.