AMD is in the hot seat again. This time it’s not about company earnings, but AMD’s marketing claims about the power of its Bulldozer CPU platform. In late October, one disappointed AMD buyer filed a class action lawsuit arguing that AMD’s statements about Bulldozer supporting up to eight cores were false.

Tony Dickey, a resident of Alabama who brought the suit against the company, says AMD’s actions violate the consumer legal remedies act, California’s unfair competition law, false advertising, fraud, breach of express warrant, negligent misrepresentation, and unjust enrichment.

At issue is how Bulldozer CPU cores work. AMD takes two cores and packs them into a single package called a module. The problem is that these two cores within a module cannot operate independently, according to the suit. Thus, an 8-core Bulldozer CPU effectively has four cores since the eight cores cannot work on eight instructions independently and at the same time, the suit alleges.

“AMD tricked consumers into buying its Bulldozer processors by overstating the number of cores contained in the Bulldozer chips,” according to the complaint. “Average consumers in the market for computer CPUs lack the requisite technical expertise to understand the design of [AMD’s] processors, and trusts [AMD] to convey accurate specifications regarding its CPUs.”

Although the lawsuit was filed in late October it only recently came to light. AMD was unavailable for comment at this writing.

Why this matters: The functionality of AMD’s CPUs is a critical issue for many PC enthusiasts such as gamers or anyone requiring a large amount of computing power in their desktop rig. Whether Dickey’s claims will survive a legal challenge, however, is unclear. Joel Hruska over at ExtremeTech isn’t buying the claim that AMD’s eight-core processors perform like a quad-core CPU, saying it’s “utterly without technical merit.” That site’s testing shows that multi-threaded applications scale up in performance as more Bulldozer CPU cores are used. PCWorld’s look at Bulldozer’s performance when it first came out in 2011 found that AMD’s eight-core FX-8150 performed comparably to Intel’s quad-core i5-2500K while requiring more power.

The claim against AMD comes just as the company is getting ready to transition from Bulldozer towards its upcoming Zen CPU platform in 2016. Zen promises notable improvements over Bulldozer including Simultaneous Multithreading, which is similar to Intel’s Hyperthreading. Zen will also offer a 40 percent improvement in performance over Bulldozer, AMD claims.

[via LegaNewsline]