Who says AMD moves too slowly? Just a month after releasing its well regarded Phenom II mid-range CPUs, the company is back with no fewer than five new P-II chips and its new AM3 socket that support DDR3. We give you the skinny on AMD’s latest quad and tri-cores and help you sort through AMD’s bewildering array of CPU choices.

War. What is it good for? Absolutely nothing. Well, except when it’s a CPU war. In that case, it’s good for consumers. Really good for us. With the unveiling of five new AMD’s latest Phenom II CPUs supporting DDR3, it’s pretty clear that the CPU war that started with the unveiling of the Phenom II in January is escalating.

AMD’s new lineup includes the 2.6GHz Phenom II X4 for $175, the 2.8GHz Phenom II X3 720 Black Edition at $145, and the 2.6GHz Phenom II X3 710 for $125. AMD’s two other new chips: the 2.6GHz Phenom II X4 910 and the 2.5GHz Phenom II X4 805. The 910 and 805 are OEM only CPUs and pricing was not released but you can expect that gray-markets will carry them and that the prices will follow the numbers. The 805, for example, should be slightly cheaper than the $175 810 and the 910 should be cheaper than the $195 Phenom II X4 920.

Lost in the numbers? So where we. AMD’s lineup is so bewildering to us today that we had build a spread sheet just to sort it out!

There are five prominent things to note with the new CPUs: They all support AM3, the HyperTransport speeds are higher, the L3 cache size is different, the tri-cores are back and the thermals are lower. We’ll address these in order.

AM3 socket

AM3 is AMD’s new socket standard that is built to support DDR3. The good news is that AM3 CPUs feature both DDR2 and DDR3 controllers. This means you can install an AM3 CPU in an AM2+ (and even some AM2) motherboards. You cannot, however, install an AM2+ CPU in an AM3 board. To prevent damage, the AM3 sockets have two fewer pins so you can’t even physically insert an AM2+ CPU in the socket. All Phenom II CPUs except for the two original launch CPUs should be AM3-based.

Can you spot the two fewer pins on the AM3 CPU on the right vs. the AM2+ CPU on the left?

Why didn’t AMD make the two original chips (the Phenom II X4 940 and 920) AM3 too? The company said it wanted to get them out as soon as possible and ditching AM3 support a cut quite a bit of engineering time off. We can understand that but it’s only been a month since the 940 and 920 were unveiled so couldn’t it have waited just a little longer so as not to confuse the hell out f people and piss off 940 and 920 owners? Apparently not. In fact, we’ve been told by AMD officials that the 940 and 920 actually had the AM3 controllers in them but they not turned on. If we ever get the time, we’ll have to snip the pins off a Socket AM2+ 920 and see what happens when it’s inserted into an AM3 motherboard.

HyperTransport Speeds

The newest Phenom II all sport 4GHz HyperTransport speeds. The original Phenom II X4 940 and 920 only ran at 3.6GHz HyperTransport speeds. Why? Again, AMD said it need to cut a few corners to get the 940 and 920 out as soon as possible and limiting the speeds to 3.6GHz help it do that. The company notes that it’s not like the CPUs are saturating the bandwidth anyway so it should have no real impact on performance. We, frankly, haven’t noticed that much of a difference either and we have to note that only the original Phenom X4 9950 and Phenom X4 8850 sported the 4GHz HyperTransport speeds. All others were lower.

If you’re really interested in how AMD’s Phenom’s look from an HT speed context here’s our chart sorted by HyperTransport speeds: