Socket AM2 (940) vs Socket 940. What's the difference?

[OptyTrooper]

Okay there seems to be a bit of confusion about the difference b/t these two platforms so for those of you not in the know here is a brief run down.

In the first attachment we have the familiar AMD Socket AM2. Notice the designation (940) after AM2. In this case it refers to the pin count to differentiate it from it's predecessor Socket 939. I imagine you all already know this and what platform AM2 processors work in so let's move on.

In the second attachment we have a CPU-Z screen shot of a Socket 940 processor. Notice after AMD Opteron 275 it has the designation (DP). This signifies a Dual Processor platform. For the most part these processors were designed for server and high end workstation solutions. The exception would be the Athlon 64 FX-51.

So what's the difference? These are few of the major ones. For our purposes they will suffice.

Socket AM2 (940)

Single socket platform only.
DDR2 unbuffered
90nm-65nm

Socket 940

Dual socket platform or greater.
DDR ECC registred memory only.
90nm.

Despite having the same number of pins, Socket 940 and AM2 are not pin-compatible.

For more detailed specifications see:
http://en.wikipedia.org/wiki/Socket_AM2
http://en.wikipedia.org/wiki/Socket_940
http://www.amd.com/us-en/Corporate/VirtualPressRoom/0,,51_104_572_573%5E14062,00.html
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/25766.pdf

SocketAM2.jpg

[pioneerisloud]

Just to clarify one more thing here. Socket 940 also had a few single socket boards too. But for the most part this information is 100% correct. Basically, 940 = Server for Socket 939. Socket AM2 = AMD's first generation mainstream DDR2 socket.

[Antinomy]

A bit of history:

First the was the AMD Hammer codename. It was the K8 architecture. The first mainstream socket for K8 was socket 754. It was a single socket and had single memory channel.

The more pricey "extreme" version was the FX-51 that used the server socket, 940. Socket 940 was developed for servers and supported multiCPU configurations and two memory channels. As adding more memory made hard work for the integrated memory controller, the memory should be only buffered.

After this a new desktop socket arrives that took the best from two worlds - two memory channels and unbuffered memory. It was socket 939. There was a number of limitations caused by memory - first only DDR266 was the max frequency for 4 sticks. Then a new memory controller revision allowed using DDR333. And then - DDR400 but with CR=2T.

Them DDR2 came along with socket AM2 and so on.

[pioneerisloud]

A bit of history:

First the was the AMD Hammer codename. It was the K8 architecture. The first mainstream socket for K8 was socket 754. It was a single socket and had single memory channel.

The more pricey "extreme" version was the FX-51 that used the server socket, 940. Socket 940 was developed for servers and supported multiCPU configurations and two memory channels. As adding more memory made hard work for the integrated memory controller, the memory should be only buffered.

After this a new desktop socket arrives that took the best from two worlds - two memory channels and unbuffered memory. It was socket 939. There was a number of limitations caused by memory - first only DDR266 was the max frequency for 4 sticks. Then a new memory controller revision allowed using DDR333. And then - DDR400 but with CR=2T.

Them DDR2 came along with socket AM2 and so on.

Really? That's actually new information for me to absorb! And I've been on 939 for about 6 years now! I thought DDR333 was THE limitation on 4 DIMM's, but DDR400 could be achieved usually with overclocking the HTT. I mean, I can personally run the DDR400 divider, but I thought that was a rare and freak accident.

[OptyTrooper]

Just to clarify one more thing here. Socket 940 also had a few single socket boards too. But for the most part this information is 100% correct. Basically, 940 = Server for Socket 939. Socket AM2 = AMD's first generation mainstream DDR2 socket.

Nope. 940 was introduced prior to 939 by quite a bit. It's inception was actually a bit prior to 754 even as Antinomy touched on.

[Bones]

Yep, Antinomy is on top of things as usual.

[ShrimpBrime]

Socket 940

Dual socket platform or greater.
DDR ECC registred memory only.
90nm.

130 and 90nm. The 130nm over clock decently too!