This is an interesting discussion and all, but for a moment I'm going to ask you to stop.
Now that I've asked the impossible, let me explain why. You have to argue this with a judge (and depending upon the case structure and local rules a jury). Said judge can be anything from technically savvy, to barely able to turn on their television set. Now that we've framed the discussion, let's argue the point.
1) Define what a core is, to the lay person.
a : a basic, essential, or enduring part (as of an individual, a class, or an entity) <the staff had a
core of experts> <the
core of her beliefs> -According to Merriam Webster online dictionary-
2) How is this definition applied to the case at hand?
A critical component to the processor is missing, thus preventing you from calling your CPU "8 cores" due to this fundamental component being removed.
3) How do you prove it?
-Fail- AMD can pull out a wealth of nice pretty graphs that demonstrate their processors perform at the same level as a similar core count offering from their competitors. These programs can be cited as utilizing the number of cores better than other programs, and the burden of proof falls to the accuser to prove that this is not the case. The accuser can provide charts all day proving that the processor doesn't work as well on some programs, yet without the source code to prove it they're completely without a valid accusation.
4) What experts support your claims?
-Fail- AMD can wheel out an assortment of experts in the computing field. Each of them can attest that in a very specific type of loading their product performs better than their own 4 core offerings, thus invalidating the claim that 8 cores aren't performing better than 4. If the accuser compares them to Intel, they need only state that they are a competitor with a different and non-comparable product. It then rests on the accuser to prove they are comparable, which would take enough technical jargon to completely alienate a jury. The accuser can therefore not really level an accusation here that isn't killed by its own complexity.
5) How are damages being calculated?
-Fail- This is fuzzy at best. If the accuser says that an 8 core AMD CPU is comparable to an 8 core Intel one they've got to quantify the massive gulf in pricing. That will be nigh impossible. If they want to argue an 8 core processor is less efficient than a quad core then they've got to be able to compare like measurements to justify any losses. AMD needs only wheel out the "we aren't Intel" argument to make this impossible (there is literally nothing that these can be directly compared to).
6) Does the judge have an unbiased opinion?
-Fail- This is a lawsuit in Northern California. Let's be honest here, damaging AMD isn't in the best interest of the locals, and this is a largely frivolous suit. It's being filed years after Bulldozer hit the market. It is initiating class action without having much of a basis from which to stand (given all the technical material available stating that the "core" of Bulldozer was something entirely new). But worst of all is that the suit's associated lawyers, a new kind of vampire that is more than happy to sue about anything related to technology. Seriously, read through their site, it's the most atrocious vulture group since the copyright trolls:
http://www.edelson.com/in-the-news/
I'm all for making AMD aware that their crap with the Bulldozer "core" is unacceptable, we did that by not buying it. I don't have a problem with law suits which are directed at reparations directly related to a wrong done by someone, this is what the legal system is designed for. What we've got here though is utter crap. Somebody raising a suit too late to be relevant, not seeking reparations for consumer benefits, and worst of all hiring a law firm that banks on technology being too complex for our legal system to wade through as is. Sorry, but the accuser is a vampiric douche who is using the legal system as a weapon. If they got hit by a car tomorrow I think the gene pool would be better off (along with the legal offices being swallowed up in a massive sink hole).
Edit:
Let me be even more angry about this stupidity. Here's what Anandtech said in 2009:
http://www.anandtech.com/show/2881/2
2 years before Bulldozer was released this information was publicly available. Ignorance of the law is not an excuse not to follow it. Likewise, this kind of ignorance to what you are buying doesn't make the accuser deserving of reparations for their idiocy. I wonder if AMD maintains PR release information (I say sarcastically)? I wonder if this idiot ever read any of them, or when they're introduced in court his legal team will be able to dismiss them as...I can't even imagine how you'd argue your client isn't a moron at that point.