Question What Was the First AMD CPU to Feature Hyper-Threading (Multithreading) Technology?

jnjnilson6

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We all know Hyper-Threading fired up in the beginning of the 2000's with the Pentium 4's. My question is - When did that technology move over onto the AMD counterpart and become a thing there too? I have searched a little bit on the topic but do not know exactly the years and models by which the change first began in the case of AMD. It is interesting to know that with Zen and current AMD processors there are virtual cores to further extend performance and bring forth higher multitasking needs.

Thank you for writing up!
 
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Up to bulldozer (fx) AMD only had normal cores, they filled the spots of the HTT intel chips competition with 3core cpus.
Bulldozer was a hybrid weird thing with real full integer cores but shared floating point units, they just physically broke up the resources of a normal integer core into two separate ones to make them "hyper threaded" .
Ryzen is their first architecture with real SMT


This is all just from memory I could be completely wrong...
 
Bulldozer is the first AMD architecture to effectively leverage the use of multithreading, which is basically their "version" of hyperthreading for that time.


The first ACTUAL hyperthreading for AMD, which still is not exactly the same as what Intel does, was Zen.

AMD Zen Family 17h – the successor to Bulldozer. First AMD architecture to implement simultaneous multithreading and Infinity Fabric. Based on 14 nm process, included in the Ryzen CPU line.
 
The first thing to note is the technology is not called "HyperThreading." The generic term is simultaneous multithreading (SMT). "HyperThreading" is just Intel's trade name for it.

Zen is the first CPU with simultaneous mulithreading. Bulldozer uses clustered multithreading (CMT). The difference is the number of available execution units is fixed per thread in CMT, whereas in SMT, the primary thread uses as many execution units as it can while the secondary thread gets to use the leftovers.

To put this in an example, if there are say 8 execution units, a CMT based CPU would split this up in half. So a thread can only use up to 4 execution units even if the thread could use more. In SMT, the primary thread has access to all 8 units, but if it doesn't use all 8, the secondary thread can use whatever's left.
 
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Like I said, Bulldozer was the beginning of the beginning of any kind of threading TYPE behavior for AMD.

I might have some idea about this architecture after all. 🤣

Yeah, I know I need to fix the images. Shows you how long it's been since I looked at it at all. It was PRE-tinypic shutting down. I'll fix the broken images pretty soon now that I know.

 
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Karadjgne

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Bulldozer was wierd anyway you want to look at it. Amd claimed it was upto 8 cores on the fx8 series and Intel had an issue with that over a technicality, costing amd a small fortune to defend. And eventually lost, so the 8 core fx was relabeled a 4core/8thread cpu, no different to the core-i series.

Which made it AMD's first multi-threaded core, in that respect, whether it was CMT or Hyperthreading or SMT is semantics. Amd didn't actually design a true (to them) multi-threaded core until Ryzen/Threadripper in 2017.
 
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Karadjgne

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Intel had everything to do with that, don't kid yourself. Intel was fighting dirty for that whole period of time, if not directly suing Amd, it was done indirectly. There wasn't a bios or piece of software that'd label the FX8 series as anything but an 8 core cpu, consumers agreed, everyone agreed except Intel who started the whole disagreement. The class action lawsuit came about because Intel objected and some consumers saw it as a way to get money back for seriously lackluster performance after all the hype about an 8 core cpu. Doesn't really matter that it was consumers who actually sued amd, Intel was the mouthpiece behind it all. If amd folded of its own accord, Intel would have zero competition and not have violated any anti-trust regulations.
 
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Intel DID have everything to do with that, but had it been the other way around AMD would have been just as loudly quietly supporting it through it's own lobbying efforts in the hallways and alleys of the legal system. None of these companies are your friend and none of them are altruistic.
 
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