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AMD Sued Over Allegedly Misleading Bulldozer Core Count
An anonymous reader writes: A class action suit accuses AMD of misleading buyers about the number of cores in its Bulldozer-based CPUs. The complaint claims that the chips effectively had only four cores, while AMD claims there are eight. According to Ars: "AMD's multi-core Bulldozer chips use a unique design that combines the functions of what would normally be two discrete cores into a single package, which the company calls a module. Each module is identified as two separate cores in Windows, but the cores share a single floating point unit and instruction and execution resources. This is different from Intel's cores, which feature independent FPUs. The suit claims that Bulldozer's design means its cores cannot work independently, and as a result, cannot perform eight instructions simultaneously and independently. This, the claim continues, results in performance degradation, and average consumers in the market for a CPU lack the technical expertise to understand the design of AMD's processors and trust the company to give accurate specifications regarding its CPUs."
http://www.extremetech.com/extreme/217672-analysis-amd-lawsuit-over-false-bulldozer-chip-marketing-is-without-merit
AMD's CPU architecture has a similar purpose as hyperthreading -- to share hardware resources between what looks to the OS like independent cores -- but the tradeoff is different. Intel's hyperthreading approach only works to cover memory latency, because the hyperthreads share so many physical resources (I think basically everything except register files and hyperthreading-related state). AMD's is somewhat different in that each "module" has two independent integer ALUs, register files, and L1 data caches. The module has one L1 instruction cache, one L2 data cache, one FPU, and one instruction fetch/decode unit.
But AMD has always been pretty up-front about this architecture. There is maybe a cause of action against resellers who package the AMD chips into systems and do gloss over which aspects each "core" shares with another core, but AMD publicly presented the core-vs-module distinction well before the chips were released.
AMD has always been behind Intel in the performance area for most of its life.
Well, there was the Athlon - era where they were sweeping the floors with Intel; the classic Athlons and Athlon XPs were phenomenal CPUs at the time and highly overclockable. It was glorious, but yeah, I think that was pretty much the only time they beat Intel.
Lets hope AMD gets their shit together. As I've said before. The fat lady hasn't sung yet on AMD but she is warming up in the bullpit. Lets hope that as she waddles up on stage AMD pulls a rabbit out of the hat and she falls off the stage into a tuba.
I really, *REALLY* hope they can manage to do it, but.. I just haven't heard any promising news in that regards anywhere. There's quite literally nothing to indicate that AMD has in any way or form stopped digging even further down the hole they are already in. I do dread the day when Intel becomes the sole x86 - vendor and can practically demand whatever they want, do whatever they want and laugh all the way to the bank.
Err except with HT there is one execution unit, and with AMD there are two.
They are real cores, that share instruction decode and a FPU.
Actual execution is parallel (unlike HT which is more interleaved).
HT isn't similar to Bulldozer modules in any sense.