AMD has agreed to a $12.1 million settlement in a class action lawsuit for some customers who bought its FX-8000 / 9000 CPUs built on its 2011 Bulldozer architecture, ending a years-long dispute that claimed AMD falsely advertised the chips as eight-core processors when they in fact only possessed half that number, via The Register.

According to the lawsuit, the Bulldozer-based chips weren’t truly multicore processors to the extent that AMD claimed. AMD advertised the CPUs as eight-core chips, but each chip only had four “dual-core modules” with separate execution units; other resources like cache and a single floating point unit (FPU) were shared across the module. AMD says that those modules counted as two cores each, for a total of eight, but customers alleged that since the modules couldn’t actually run separate processes, they only should count as a single core for a total of four cores, not the eight that AMD claimed.

Two cores, or not two cores... that is the question

Under the settlement, AMD will pay out $12.1 million to a settlement fund, which AnandTech calculates out to cover the attorney fees (roughly $3.63 million), settlement administration (between $350,000 and $700,000), leaving roughly $8.12 to $7.77 million to split between the eligible customers.

To be eligible for the settlement, you’ll need to have bought the specific CPU models in question (specifically, AMD FX-8120, FX-8150, FX-8320, FX-8350, FX-8370, FX-9370, and FX-9590 chips), and have purchased your CPU from AMD’s website or in the state of California.

It’s unclear how much customers will actually get — the settlement notes that the court expects roughly one-fifth of the class members to actually apply for the payout, but that if more people do apply, they should still receive about $35 per chip. But until the final settlement is approved and class members actually start applying (the process of which has yet to be announced), it’s hard to tell for sure how much to expect.