Wednesday, January 23rd 2019
Bulldozer Core-Count Debate Comes Back to Haunt AMD
AMD in 2012 launched the FX-8150, the "world's first 8-core desktop processor," or so it says on the literal tin. AMD achieved its core-count of 8 with an unconventional CPU core design. Its 8 cores are arranged in four sets of two cores each, called "modules." Each core has its own independent integer unit and L1 data cache, while the two cores share a majority of their components - the core's front-end, a branch-predictor, a 64 KB L1 code cache, a 2 MB L2 cache, but most importantly, an FPU. There was much debate across tech forums on what constitutes a CPU core.
Multiprocessor-aware operating systems had to be tweaked on how to properly address a "Bulldozer" processor. Their schedulers would initially treat "Bulldozer" cores as fully independent (as conventional logic would dictate), until AMD noticed multi-threaded application performance bottlenecks. Eventually, Windows and various *nix kernels received updates to their schedulers to treat each module as a core, and each core as an SMT unit (a logical processor). The FX-8350 is a 4-core/8-thread processor in the eyes of Windows 10, for example. These updates improved the processors' performance but not before consumers started noticing that their operating systems weren't reporting the correct core-count. In 2015, a class-action lawsuit was filed against AMD for false marketing of FX-series processors. The wheels of that lawsuit are finally moving, after a 12-member Jury is set up to examine what constitutes a CPU core, and whether an AMD FX-8000 or FX-9000 series processor can qualify as an 8-core chip.
US District Judge Haywood Gilliam of the District Court for the Northern District of California rejected AMD's claim that "a significant majority of" consumers understood what constitutes a CPU core, and that they had a fair idea of what they were buying when they bought AMD FX processors. AMD has two main options before it. The company can reach an agreement with the plaintiffs that could cost the company millions of Dollars in compensation; or fight it out in the Jury trial, by trying to prove to 12 members of the public (not necessarily from an IT background) what constitutes a CPU core and why "Bulldozer" qualifies as an 8-core silicon.
The plaintiffs and defendants each have a key technical argument. The plaintiffs could point out operating systems treating 8-core "Bulldozer" parts as 4-core/8-thread (i.e. each module as a core and each "core" as a logical processor); while the AMD could run multi-threaded floating-point benchmark tests to prove that a module cannot be simplified to the definition of a core. AMD's 2017 release of the "Zen" architecture sees a return to the conventional definition of a core, with each "Zen" core being as independent as an Intel "Skylake" core. We will keep an eye on this case.
Source:
The Register
Multiprocessor-aware operating systems had to be tweaked on how to properly address a "Bulldozer" processor. Their schedulers would initially treat "Bulldozer" cores as fully independent (as conventional logic would dictate), until AMD noticed multi-threaded application performance bottlenecks. Eventually, Windows and various *nix kernels received updates to their schedulers to treat each module as a core, and each core as an SMT unit (a logical processor). The FX-8350 is a 4-core/8-thread processor in the eyes of Windows 10, for example. These updates improved the processors' performance but not before consumers started noticing that their operating systems weren't reporting the correct core-count. In 2015, a class-action lawsuit was filed against AMD for false marketing of FX-series processors. The wheels of that lawsuit are finally moving, after a 12-member Jury is set up to examine what constitutes a CPU core, and whether an AMD FX-8000 or FX-9000 series processor can qualify as an 8-core chip.
The plaintiffs and defendants each have a key technical argument. The plaintiffs could point out operating systems treating 8-core "Bulldozer" parts as 4-core/8-thread (i.e. each module as a core and each "core" as a logical processor); while the AMD could run multi-threaded floating-point benchmark tests to prove that a module cannot be simplified to the definition of a core. AMD's 2017 release of the "Zen" architecture sees a return to the conventional definition of a core, with each "Zen" core being as independent as an Intel "Skylake" core. We will keep an eye on this case.
369 Comments on Bulldozer Core-Count Debate Comes Back to Haunt AMD
How much is the multicore speedup for integer math tasks between a 4 module AMD is it around 3.xx or 7.xx? Now compare that to a traditional 4 core setup.
In these specific scenarios it is quite easy to see any and all argument to say that the AMD design act as any standard 8 core unit would. Just because single threaded performance was dreadful, doesn't have anything to do with it scaling linear across all 8 cores available assuming integer calculations.
look at it like this if amd were right and the rest of us were wrong and there was never an issue.. well this thread wouldnt even exist.
hell if we were all wrong. amd wouldnt have had to beg ms to treat 1 module as a single core and the second "core" in that module as little more than hyper threading to prevent the bottle necks because 1 module couldnt do the same workas 2 cores when 2 actuall cores could.
you cant just sell people a bycicle without a front wheel and say it works fine, then after ppl complain say well you should know we meant you need to do a wheelie all the time.
and they did that because one module cannot do the same work as 2 real cores, which is also why zen uses real cores now.
4 module, each module has 2 cores sharing resources.
Also, just because it doesn't scale perfectly doesn't mean it's not two different cores. Two lite cores are still two cores.
I absolutely see the issue. AMD changed what a portion of people considered to be a core. The IEEE would be pretty openly considered the subject matter experts on all things electrical correct? With its 420000 members?
Because they signed of on the verbiage of 2-core module for chip-level multithread or CMT as AMD labeled it for the Bulldozer design. If this lawsuit makes it to fruition that on its own should have it dismissed. The experts across the board approved the phrasing.
Here are a couple of IEEE documents for you to read on the subject
ieeexplore.ieee.org/document/6060836
This is from all the way back in 2010, where yet again BD is referenced openly in IEEE publications as using cores. This even states how the cores are sharing resources.spectrum.ieee.org/semiconductors/processors/multicore-cpu-processor-proliferation
i cant even begin to tell you how rediculous that is.
Like i keep saying agree to disagree but if i ever want to sell something thats missing bits and does not work as intended il let you know.
"Just adding traditional cores isn’t going to be enough, says AMD’s Moore. "
which Also right there says they arent cores. AMD said they arent cores right there in that stupid thing you just quoted.
oh and the paper is for a "module" not a "core"
All the evidence you bring just contradicts what you say.. and yet you still say it!
For integers, typical hyper-threading CPU has strong and weak threads.
Gimme your keys, @Shambles1980. You're drunk.
right fine i guess, not much i can do in the light of that.
although i will admit i thought you were the one that quoted it, so il confess to that.
no one complained for them bing modules.. the issue is they call them 8 cores when they are demonstrably not.
Edit: That means fewer instructions per clock per core compared to its predecessor.
I dont mind them calling them Lite cores. or integer cores or imaginary cores.. hell they could have called them anything they wanted aslong as they defined the difference to the avarage idiot on the street
but they didnt sell them like that which is the issue.
I dont see how you cannot comprehend that.
But there is a "TRADITIONAL CORE" what people are used to. even amd admit it in the paper above.
Then there are modules And you can call whats in those anything you want to call them aslong as you make a destinction, Which amd briefly did.
the issue is they decided to just go on the "look at us 8 reall cores" marketing thing. I was always against it and spoke out at the time.
Would i try and sue them for it?? no because I knew what to expect..
Would my family have known better?? hell no.
Should people who were duped be allowed to try and get some justice?? yes..
Should this law suit continue?? Yes..
If for no other reason that for mfrs to just accept they cant just trick the uneducated.
You havd vista ready and vista capable years ago that ended up in the same situation as this. and thats even less clear cut.
i have no doubt in my mind if moduels had been super effective, then every one would have moved on to call them cores. But they werent and so we didnt and we wont.