Core blimey... When is an AMD CPU core not a CPU core? It's now up to a jury of 12 to decide
A class-action lawsuit against AMD claiming false advertising over its "eight core" FX processors has been given the go-ahead by a California judge.
US district judge Haywood Gilliam last week rejected [PDF] AMD's claim that "a significant majority" of people understood the term "core" the same way it did as "not persuasive."
What tech buyers imagine represents a core when it comes to processors would be a significant part of such a lawsuit, the judge noted, and so AMD's arguments were "premature."
The so-called "eight core" chips contain four Bulldozer modules, the lawsuit notes, and these "sub-processors" each contain a pair of instruction-executing CPU cores. So, four modules times two CPU cores equals, in AMD's mind, eight CPU cores.
And here's the sticking point: these two CPU cores, within a single Bulldozer module, share caches, frontend circuitry, and a single floating point unit (FPU). These shared resources cause bottlenecks that can slow the processor, it is claimed.
The plaintiffs, who sued back in 2015, argue that they bought a chip they thought would have eight independent processor cores – the advertising said it was the "first native 8-core desktop processor" – and paid a premium for that.
(Score: 3, Insightful) by takyon on Wednesday January 23 2019, @10:02PM (3 children)
I don't think anyone would have sued and gotten this far if the Bulldozer architecture wasn't such shit and hyped by AMD.
The new 24- and 32-core Threadripper 2 CPUs have potential bandwidth/latency issues for half of the cores, but I don't see any lawsuits.
Nvidia settled [arstechnica.com] a class action lawsuit over GTX 970's VRAM issue.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by The Shire on Wednesday January 23 2019, @10:25PM (2 children)
When buying a processor most folks look to see what the actual benchmarks are before purchase. I agree this architecture has all kinds of flaws that hobble its performance, but it doesn't change the fact that there are 8 instruction executing cores.
(Score: 2) by toddestan on Saturday January 26 2019, @12:13AM (1 child)
Actually, that fact isn't even really true. Because of the shared FPU's, if they are floating point instructions you've only got 4 executing cores.
(Score: 2) by The Shire on Saturday January 26 2019, @09:34PM
Well yes and no. Floating point calculations are only a subset of the total CISC catalog, so depending on how you parse the instruction queue you can have one core running fpu calculations while the other does logic, branching, integer, or memory operations. The whole design is sub optimal to say the least but I would still say it's technically true to call it an 8 core processor, albeit one that sucks for things like coin mining.
Bottom line is "buyer beware". They should have evaluated the performance characteristics before buying it.