Back in 2015, AMD was sued by a pair of individuals claiming that the company lied when it sold Bulldozer products to customers. The lawsuit — which I have always believed is without technical merit — essentially conflated being disappointed with the FX family’s performance with the idea that AMD had lied by marketing Bulldozer as an eight-core CPU.
AMD has agreed to settle the case for the relatively low sum of $12.1M. According to the lawsuit, this is a sufficient sum of money to ensure that the members of the class will receive compensation of at least $35, even if up to 20 percent of the class members notify that they wish to be included in the settlement — a rather high number. The brief estimates that between 50,000 and 150,000 people may seek reimbursement for purchases of Bulldozer or Piledriver parts.
Members of the settlement class are defined as individuals who purchased “one or more of the following AMD computer chips either (1) while residing in California or (2) after visiting the AMD.com website: FX-8120, FX-8150, FX-8320, FX-8350, FX-9370, and FX 9590.”
That’s one of the ways you can tell that this lawsuit didn’t actually have any merit to it: It’s confined to AMD’s eight-core CPUs. There’s no logical reason for this to be true — if AMD actually falsely advertised its eight-core chips, it also falsely advertised its six-core, quad-core, and dual-core CPUs as well. AMD had a top-to-bottom product mix in-market based on Bulldozer and its derivatives. If the eight-core chips aren’t “real” eight-cores because they shared resources, then why are the other chips off the hook?
There’s one line in the brief that still grates on me, even though the lawsuit is settled. “According to Plaintiffs, the “cores” in the Bulldozer line are actually sub-processors that cannot operate and simultaneously multitask as actual cores.”
This is untrue. For an example of a CPU with true sub-processors, look to Sony’s Cell Broadband Engine. The Cell had a Power Processor Element (PPE) and up to eight secondary Synergistic Processing Elements (SPEs). Seven of these were enabled for the PS3. As RealWorldTech wrote (concerning Cell):
The function of the PPE is to act as the host processor and perform real time resource scheduling for the SPEs. To implement those functionalities, PPE modules must be written to perform generic processing tasks and I/O handling. Then, to fully utilize the power of the CELL processor, programmers must focus their attention on the creation of SPE modules. Each SPE module should use multiple SPE threads to take advantage of the parallelism afforded by the multiple SPE’s. To simplify the task of scheduling, all SPE threads in an SPE module are always scheduled simultaneously. Furthermore, SPE threads within an SPE module are started and stopped at the same time to reduce the complexity of synchronization. However, the complexity of scheduling remains and a PPE module must handle the scheduling of the SPE’s on a module-by-module basis.
If you want an example of a CPU that has “sub-processors” that must then be corralled and properly fed in order to keep performance high, it’s Cell, not Bulldozer. Bulldozer didn’t have “sub-processors.” Bulldozer shared certain execution units and, as we’ve documented before, continued to offer improved performance when workloads scaled above four threads. It did not have an asymmetrical core configuration with one core used for scheduling workloads on all the others.
No, Bulldozer and Piledriver chips didn’t offer equivalent performance to their Intel counterparts, which is why AMD’s CPU prices were so low for much of the same time period. In 2014, an FX-9590 could be had for as little as $229. The equivalent eight-core Broadwell HEDT CPU in 2015 was well over $1000. And one of the basic rules of PC components that still generally holds true is that higher prices tend to equal generally higher performance.
The problem with this lawsuit is the same as it ever was. The plaintiffs wanted to pretend that AMD’s lower performance constituted false marketing because one AMD core offered dramatically less performance than one Intel core. But CPU cores are not defined by performance, and this lawsuit has never even attempted to articulate a technical distinction between Bulldozer and Piledriver’s resource sharing and the resource-sharing of other CPUs.
This lawsuit was never grounded in a technical argument over the definition of a CPU core. At least now it’s dealt with.