When is a six-core PC processor not a six-core PC processor? When it's AMD's new FX 6100 Black Edition.

Long before AMD released its fancy new FX chips, we had a feeling a fisticuffs was brewing over the definition of what constitutes a processor core.

Now the FX has arrived and the gloves are off.

It all comes down to the radical new approach to simultaneous multi-threading (SMT) taken by AMD with the new Bulldozer architecture.

Intel's been doing SMT for a bit in the form of Hyper-Threading and fair to say Chipzilla's take can be called SMT lite.

It hasn't spent a lot of transistors in enabling each of its processors cores tow run two software threads in parallel. So a multi-threading performance boost of around 15 to 20 per cent is a pretty decent outcome.

AMD reckoned it could do better and verily cooked up the Bulldozer module. This little techno-beasty packs a pair of execution units. But much of what you'd normally consider a processor core is shared.

So has that Bulldozer module got enough power to give this six core processor a chance?