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  • The tech jargon is, well, jargon so let me simplify things for you.

  • First up, I want you to erase every preconceived notion you've had about AMD FX Cores.

  • When you see the FX 6300 advertised as a Hexa(6)-Core Processor

  • or the FX 8350 advertised as an Octa(8)-Core Processor.

  • You're looking at facts. By acceptable definitions, these processors have the correct number of cores specified.

  • But they are not designed and do not function in the same way that equivalent Intel cores do.

  • And that's what this video will seek to clarify.

  • The two architectures that we'll be comparing are:

  • The Bulldozer Architecture from AMD, most notably found in the FX 8000 Series.

  • And the Sandy Bridge Architecture from Intel, which you'll find in their core 2000 series and a few others.

  • Although you could stretch this to any modern Intel CPU, they haven't really changed much in this sense

  • So let's consider the FX 8350 and the i7 2700k

  • It's not a 2700k, but you get my point

  • In these 2 cases, things on paper look fairly similar

  • Well, apart from price

  • Transistor Architecture is identical, 32 nanometers for both

  • They both have 8 threads

  • They both have 8 Megabytes of L3 Cache

  • They also both have unlocked multipliers

  • But the FX 8350 is advertised as an 8-Core processor

  • Whereas the i7 2700k is only advertised as a Quad-Core with Hyper-Threading

  • A technology implemented by Intel to increase Instruction Processing.

  • Essentially, here's a crash course in Hyper-Threading:

  • A single Intel core is split up into two quote-unquote Logical cores

  • which share a total workload and increase processing efficiency

  • This is explained clearly in Intel's 2012 Architecture Manual

  • quote, if both logical cores are active, the queue is partitioned so that

  • both logical processors can make independent forward progress, end quote

  • Independent, that's the key word here. An adept scheduler efficiently allocates data

  • between two logical cores, one of which could be busy processing,

  • and the other which could be demanding more information

  • So how is this hyper-threaded i7 any different from an eight-core FX processor?

  • And why can't Intel just say that their i7 27k is an eight-core processor?

  • Let's dive a little deeper. So in short the reason AMD can get away with

  • calling their 8350 an octa-core CPU and Intel cannot is because, shocker,

  • the FX processor is actually featuring 8 processing cores

  • Each core has its own unique scheduler which decides what from system memory will be processed next

  • as well as its own Level 1 cache.

  • This contrasts Intel's logical core setup in which 2 logical cores

  • rely on a single Intelligence Scheduler to disperse data. These logical cores by the way, are not physical cores.

  • In fact, there are two logical cores per physical core which means that

  • hyper-threading is really just a manipulation of one core or however many cores are in the processor

  • So yes, FX processors are special but in both good and bad ways.

  • Let's take a look at the Bulldozer Block Diagram.

  • The FX-8350 features four modules and two integer cores per module.

  • These integer cores are legitimate CPU cores, no doubt.

  • But are packed into condensed modules for the sake of space, cost and efficiency but only in some cases.

  • Each module shares 2 Megabytes of L3 cache for a total eight megabytes as described.

  • And each also shares a single FPU or floating point unit.

  • This FPU handles mathematical functions addition, subtraction, multiplication, you get the point.

  • And the fact that Bulldozer forces pairs of cores to rely on a single FPU is what raises a bit of concern here.

  • You see, on Intel's side the i7 2700k features four unique cores with four independent FPUs.

  • So one FPU per core.

  • This is a case for any modern Intel CPU, and while this alone may not seem like such a big deal

  • It's what ultimately gives Intel CPUs the clock-for-clock edge in single core performance.

  • FPUs handle most mathematical functions via the binary system.

  • And allocating a single FPU per pair of cores can result in delays or quote-unquote lag times.

  • Reducing overall performance in especially intense programs, even gaming.

  • AMD claims the opposite that a single a FPU per module

  • allows for overclocking headroom and higher mathematical complexity

  • and they're correct, in theory, this should be the case; most modern GPUs actually follow this setup as well.

  • FX FPUs themselves, technically have "Two Unique Cores"

  • But the technology over the years hasn't given the Central Processing Units the edge AMD expected them to have

  • Thanks to Windows and other programs assigning tasks in non-sequential arrays.

  • This means that, instead of software seeing an FX CPU as a true quote-unquote 8-core

  • It forces data through a pipeline similar to hyper-threading

  • Which, if you remember, is nowhere near as efficient as two independent cores.

  • This explains why CineBench for example sees the FX-8350 has a 4 core processor with 8 threads

  • And not an 8-core processor with 8 threads

  • Basically AMD banked on software following suit with their new CPU design, and that didn't happen at all.

  • In fact, from what we know about Zen it seems like AMD's falling back on what Intel has been sporting for several years now.

  • Coming at this entire debate from a different angle.

  • Processor Savvy individuals on the blue team might also make the argument that

  • Because each module only features a single Fetcher and Decoder, the two units that receive and prepare data to be processed.

  • The pair of cores within each module is essentially bottlenecked.

  • You see, much like hyper-threading which we discussed earlier;

  • FX processors feature a single point of entry, per se, for every two cores

  • Meaning that information can be bottlenecked up top, reducing the overall efficiency of each physical core.

  • Intel cores instead do not share these Fetchers and Decoders,

  • With a simple frequency calibration, Fetchers and Decoders can relay information to the Scheduler

  • At the same rate that the scheduler disperses information to the physical core or logical cores, in the case of hyper threading.

  • There are a few less relevant things I decided to leave out

  • For the sake of both: time and well, comprehension.

  • A lot was mentioned in this video but the gist of this should be rather clear.

  • While FX processors do, by definition possess the correct number of cores specified on their boxes,

  • The cores themselves are very dependent on other gates within the die.

  • Namely, the FPUs, Decoders and L2 caches, all of which individual Intel cores do not share.

  • FX Cores are also limited by software and operating system optimization, as described a moment ago.

  • Something it's safe to say is, neither the fault of AMD nor developers

  • Since Intel chips handle things much differently and it's kind of hard to play both sides of the aisle.

  • Several other factors play into the differences and processing power between, say, an FX 8350 and an i7 2700k.

  • Overall Block diagram, Design, Clock speeds and core efficiency are among them.

  • Just something to keep in mind, it would take several semesters to fully explain the architectural differences between the platforms.

  • And while I'm about to graduate with a degree in Engineering,

  • I am eons away from being able to explain these without thorough and extensive research beforehand.

  • If there's anything you'd like to add in the comments section below, by all means have at it.

  • If you liked what you saw in this video and maybe learned a thing or two, be sure to give this thing a thumbs up.

  • Give it a thumbs down if you feel the complete opposite or if you hate everything about life.

  • Be sure to subscribe if you haven't already.

  • And stay tuned for a Future PC Build as well as some interesting reviews and head-to-head clash ups that I've got planned.

  • Be sure to stay tuned for the next one, folks.

  • This is Science Studio, thanks for learning with us.

The tech jargon is, well, jargon so let me simplify things for you.

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AMD FX處理器到底有多少個核心? (How Many Cores Do AMD FX Processors *Actually* Have?)

  • 28 4
    Jerry 發佈於 2021 年 01 月 14 日
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