The introduction of the Phenom 9500 and 9600 processors was not a successful one, and it was a multi-faceted disappointment. Clock speeds were lower than expected, therefore performance was not up to par, while concerns with power consumption and the emergence of a TLB erratum in the B2 core just tossed more wood on the fire. This not only harmed its reception, but also caused many potential buyers to adopt a fence-sitting strategy, and the calls of "I'm waiting for B3" echoed throughout the online forums. AMD is finally ready to unveil the Phenom X4 50-series, with the new B3 core, and can hopefully put the past behind them.
The most important facet of the Phenom X4 B3 is the deletion of the TLB erratum. The name change to the Phenom X4 is simply going back to the roots of the processor, and re-adopting the X4 brand for the quad core, while using the X3 and X2 for the tri and dual core Phenom models. This is a great decision, as the X4, X3 and X2 designations make it very easy to determine which processor type you're dealing with, as opposed to an archaic numerical solution.
As for the existing B2 core Phenom 9500, 9600 and 9600 BE models, AMD does not intend to change the brand name to the Phenom X4, as these will fade away and be replaced by the new B3/50-series processors. The TLB erratum is fixed in the B3 core revision/50-series, but the quad core architecture remains unchanged, so don't expect any performance increases on a clock-for-clock basis.
The Phenom X4 processors are built on the 65nm SOI process, and include four individual cores, each with its own 64K + 64K of L1 instruction/data cache (512KB total L1 per processor) and 512KB of L2 cache (2MB total L2 cache). The Phenom X4 also sports 2MB of integrated L3 cache that is shared by each of the four cores, with an approximate transistor count of 450 million and a die size of 285 mm2. The processor package remains unchanged, and features the 940-pin AM2+ design, which is fully backward-compatible with the AM2 socket.
The Phenom X4 includes an onboard, dual-channel/128-bit DDR2 memory controller, with support for up to DDR2-1066 memory (with future 45nm support for DDR3). The Phenom's memory controller is flexible, and is actually dual 64-bit controllers, which can provide 128-bit dual-channel access to system memory, or be configured for individual 64-bit read/write channels. AMD also offers enhanced Cool'n'Quiet support that can dynamically change the clock speeds and voltages of each individual core, or even shut down parts of the CPU to save power.
The Phenom X4 memory controller runs at its own fixed clock, rather than using the divisor method employed by the Athlon 64 X2. There were issues with the latter design, as depending on the CPU multiplier, you could be running your DDR2 anywhere from 716 MHz up to 800 MHz. The Phenom no longer has that limitation, and now operates the DDR2 independent of the CPU frequencies, and always at the proper speed. This translates into the HyperTransport speed as well, with a 1.8 GHz HT (3.6 GHz full duplex) for the Phenom X4 9550, 9650 and 9750, and a higher 2.0 GHz HT (4.0 GHz full duplex) for the Phenom 9850 and upcoming 9950.
AMD has launched their Phenom X4 50-series of processors, which sport the new B3 core, and no longer include the famed TLB erratum. The flagship processor is the Phenom X4 9850 BE, which runs at 2.5 GHz and at a full 2.0 GHz HT 3.0 speed. The 1.2-1.3V voltage and 125W TDP specifications are also lower than the preview edition of the Phenom 9900. The base core design of 512K L1/2MB L2/2MB L3 remains the same, but since this is a "Black Edition" release, the newest Phenom X4 has an unlocked multiplier that is primed for tweaking.
AMD is also announcing several other Phenom X4 and X3 processors, in a mix of B3 and B2 cores, and intended for both channel and OEM-only distribution. The Phenom X4 9750 runs at 2.4 GHz with a 1.8 GHz HT speed, and a TDP of 125W, while the Phenom X4 9550 replaces the Phenom 9500 at a 2.2 GHz core, 1.8 GHz HT, and a 95W TDP.
Although these will eventually make their way to standard channel distribution, some of the new processors will initially go to OEMs only. These OEM-only models include the Phenom X4 9650 (2.3 GHz) quad core, Phenom X3 8600 (2.3 GHz) and X3 8400 (2.1 GHz) tri-cores, and a special low-TDP Phenom X4 9100e (1.6 GHz) quad.
The OEM market will also get a special 95W version of the 2.4 GHz Phenom X4 9750, which we can only hope quickly makes the channel migration. The Phenom X3 8600, X3 8400 and X4 9100e will use the B2 core, while the remainder are B3 versions.
Here is a small chart that should properly differentiate the various Phenom and Phenom X4/X3 models, using their clock/HT speeds, TDP, and pricing: