Four AMD sockets arrive in two years

AMD HAS FOURsocket types coming in the next two years, and that is before the variants for each market segment are taken into account. Things could get interesting, and AMD may well attract the same criticisms as Intel did in the early Pentium 4 (423/478/603/604) days. Pin counts only change once, but that is as much of a problem as a saving grace.

The first socket is the current one, AM2. There is an AM2+ and an AM3 in the works as well, all should be available in about a year. A year or so after that comes the unnamed socket for Cerberus. It is going to get mighty interesting, and with any luck AMD will build in enough logic to avoid lots of acrid smoke that used to be expensive CPUs.

AM2 is a known quantity. You can go out and buy it now. AM2+ is a variant that will arrive in the Barcelona time frame, basically Q2. It brings us the wonder of split voltage planes so you can "volt" the CPU differently from the memory controller, freeing AMD from one of its bigger frequency scaling headaches.

AM2 chips can plug into AM2+ sockets, and AM2+ chips can plug into AM2 sockets, but you will lose functionality in the latter case, and not gain anything in the former.

AM3 is the successor to AM2+ (duh), and it arrives in the Shanghai/Budapest generation. AM3 chips have HT3.0 and force a split voltage plane. You can do all sorts of tricks with HT3.0 that you could not do with HT2.x, so this will be a major step forward, but the pin count should not change.

You can plug an AM2+ chip into an AM3 socket, and plug an AM3 chip into an AM2+ socket. Again you do not gain functionality going forward, and you lose functionality going backward. This assumes that the AM3 boards do not use features that make the AM2+ chips choke like splitting HT links. While I have not heard for sure, this AM2+ chip on advanced AM3 boards does not sound feasible, so I will go out on a limb and say it won't work.

AM3 forces split voltage planes, where it is supported in AM2+ and not supported in AM2. This means AM2 and AM3 sockets and chips will not play well together no matter how hard you push them into the socket. AM2+ chips will go both ways, pun intended.

That brings us to Cerberus, and it's integrated PCIe. Guess what, you need more pins for that, lots more. This means a new physical socket, and that is not compatible with AM3. Since these parts are due in late 08, that makes it the fourth new socket in 2 years. OEMs hate this.

Remember I said something about variants? At the very least, there will be an A64 socket and an Opteron socket, so that means 8 sockets in 2 years, one a quarter. Lets not forget laptops, the occasional 4x4 tweak, and who knows what else. This means that the staid old AMD socket that never changes will change a lot.

If you collect mobos like Pokemon cards, the next two years will be a golden time for you. If you design or buy said parts, it will be more of a headache. There is good reason to do each of the moves, but the grumblings of discontent are already starting. µ