Allendale

There was contention regarding whether or not the previously available low-end Core 2 Duo desktop processors (E6300, at 1.86 GHz and E6400, at 2.13 GHz, both with 2 MB L2 cache) were specimens of the Allendale core. Prior to Q1 2007, all E6300 and E6400 processors released were Conroe (4 MB L2 cache) cores with half their L2 cache disabled. The Allendale core, manufactured with 2 MB L2 cache in total, offers a smaller die size and therefore greater yields.

Quoted from The Tech Report:

You'll find plenty of sources that will tell you the code name for these 2 MB Core 2 Duo processors is "Allendale," but Intel says otherwise. These CPUs are still code-named "Conroe," which makes sense since they're the same physical chips with half of their L2 cache disabled. Intel may well be cooking up a chip code-named Allendale with 2 MB of L2 cache natively, but this is not that chip.[18]

Another difference between the premium E6000 series (Conroe core) and the E4000 series (Allendale core) is the front side bus clock rating. The E4000 series are rated to run on a quad-pumped 200 MHz front side bus ("800 MT/s") while the E6000 series are rated to run on a quad-pumped 266 MHz front side bus ("1066 MT/s"). The E4000 series also lack support for Intel VT-x instructions.

The Core 2 Duo E4300[19] uses an Allendale core, released on January 21, 2007. The Allendale processors use a smaller mask with only 2 MB of cache, thereby increasing the number of chips per wafer. Allendale processors are produced in the LGA775 form factor, on the 65 nm process node. E6300 and E6400 CPUs have been made from both the 4 MB Conroe die and the 2 MB L2 Allendale die. The steppings of the chip differs depending on the die used- the Conroe-based E6300 and E6400 are stepping B2 and the Allendale-based E6300 and E6400 are stepping L2.

Initial list price per processor in quantities of one thousand for the E4300 was US$163. A standard OEM price was US$175, or US$189 for a retail package. The price was cut on April 22, 2007,[20] when the E4400 was released at $133 and the E4300 dropped to $113. Allendale processors with half their L2 cache disabled were released in mid-June 2007 under the Pentium Dual-Core brand name. The working cache memory was reduced by half again when the Allendale core was released under Intel's Celeron brand; the Celeron E1200 has a 512k L2 cache shared between its two cores.

On July 22, 2007, an E4500 Allendale was launched, phasing out the E4300 model.This was accompanied by a price cut for the E4400 model.