Summary: I took an old MB from the socket 939 days, teamed it up with a Dual-core Opteron and 4gb ECC memory. The MB already had built in SATA RAID and PCIe, so it's now a tidy little workstation for a real sweet price.
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 chip is bloody amazing at overclocking and its especially cheap now... The problem is that it will soon be all gone and to hit a great overclock, you need to get lucky with a good stepping number. But keep in mind, on stock speed, it is a little slow. At 2.7+ghz, this chip is indeed wicked and is a great multi tasker. It even has 1mb L2 cache, so what's not to like? My only complaint about this chip is it has a very, very low heat ceiling.