For a very long time, it was considered that stripped down versions of the Conroe processors were code-named Allendale. In actuality, Allendale is a code-name for a different processor. Many suggest that E6300 and E6400 are actually code-named Allendale, however, the E6300 (1.86 GHz) and E6400 (2.13 GHz) processors are not code-named Allendale because they physically have 4mb cache, same as their big brothers E6600 and E6700 - it is just that half of their physical memory is disabled. Traditionally, CPUs of the same family with less cache simply have the unavailable cache disabled (this allows parts that fail quality control to be sold at a lower rating). The fact that E6300 and E6400 are not code-named Allendale and actually code-named Conroe has been confirmed by Intel themselves.
Quoted from TechReport:
"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."
I'm not sure if I've posted anything about it here but I told Praetor as much.
