AMD Phenom II X2 550 BE & Athlon II X2 250 Processors

New Dual Core 45nm Socket AM3 Processors:

Since AMD started releasing processors based on the 45nm process at the end of last year, we have only seen quad and triple core chips. Today AMD is launching several new processors, all 45nm and all Socket AM3. The first big processor is the Phenom II X2 550 Black Edition, running at a 3.1 GHz and contains 6MB of L3 cache! That's the same amount of cache as AMD's flagship quad core chips. The second big processor we are going to take a look at is the Athlon II X2 250, running at a slightly lower speed of 3.0 GHz. This processor doesn't have any L3 cache, but AMD has bumped up the L2 cache to 1MB per core, or 2MB for the whole chip.

Below are pictures of the Phenom II X2 550 BE. This processor is a full size 258 mm˛ quad core Phenom II chip, with two cores disabled.

The Athlon II X2 250 on the other hand is an entirely new beast. AMD essentially took two Phenom II cores as the base, upped the L2 cache to 1MB per core, and skipped the L3 cache completely. This means that the Athlon II shares the same memory controller technology and CnQ 3.0 features as the Phenom II. This processor is only 117.5 mm˛, less than half the size of a Phenom II die, so in theory you can produce more than twice the amount of chips per wafer.

In the picture below, the CPU on the left is the typical AM2+ processor, the one on the right is an AM3. Notice the omission of a couple pins? The corresponding AM3 sockets will have those holes filled to ensure a person doesn't try to insert an older AM2+ processor into an AM3 board. Meanwhile, the AM3 chip will fit perfectly into an AM2+ board.

As with previous Phenom II releases, a BIOS update will probably be needed to ensure complete compatibility and functionality with existing AM2+ / AM3 motherboards. A small note about Athlon II, this is the first processor with hardware C1E (a low-power state enablement). Moving this power state out of the BIOS and into the CPU microcode will ensure more consistent power management implementation across platforms. Since the Athlon II is so new, current motherboards do not know how to handle this new change and a BIOS update will be needed. A simple workaround to prevent negative performance issues is to disable CnQ until your MB has proper BIOS support.