Computer Talk: CPUs And Cores -- IN PROGRESS -- June 13, 2023

Locator: 44927AAPL.  

Another huge tech story coming out after Apple's WWDC, June, 2023.

For newbies, this is a complicated story. It will be told in several parts.

It affects computer scientists, engineers, high-end developers. This does not affect you or me. As consumers or investors. But it's hugely interesting. Hugely entertaining. 

Part one.

Link here to part two.

****************
Here's My Take -- Part One

Before getting started, this is where posts like this are tracked.

Apple introduced some incredible hardware last week: desktops and laptops, and Tim Cook threw around a lot of tech-speak surrounding Apple's new M2 chips. He did not reference Apple's 3nm-M3 chip expected to debut next year, but when it does, there will be even more mention of CPUs and cores.

Later: surprise, surprise, surprise. Apple unveiled the M3 family for the MacPro laptop computers on October 30, 2030.

Years ago I sort of understood the "concept" of a CPU, ROM, and RAM, and that's about as far as I got, and then over time, I gradually lost the bubble. 

Now, cores, and I'm completely lost.

I'll provide links later.

All this "stuff" -- chips, CPUs, ROM, RAM, cores -- are virtual concepts as well as physical "things."  

I was familiar with motherboards on which chips sat -- in the old days, one could actually change out chips on the motherboards -- mostly for memory purposes. But there were "chips" for CPUs and RAM and ROM, and perhaps other "stuff" as well. I don't know.

Somewhere along the line, developers started putting all this "stuff" in one place, and called it SoC: system on a chip.

I sort of kept up, until Tim Cook started mentioning "cores." I don't recall Steve Jobs mentioning "cores." 

Steve Jobs: CPUs, RAM and ROM. 

No one understood the different CPUs -- they all had quirky names -- but everyone could follow RAM and ROM -- easy numbers -- "x" to the "nth' power -- 2, 4, 8, who do we appreciate 16, 32 and for the very rich, 64.

I'm not even going to address megabytes (MB) and gigabytes (GB).

Tim Cook: cores.

Links:

• Bloomberg, May 14, 2023: Apple's M3. 
• wccftech, June 11, 2023: Apple's M3.
  
• HP, August 24, 2022: CPU cores -- how many do you need.
• Tom's Hardware, June 17, 2022: what is a CPU core?
• How-to-Geek, March 13, 2022: CPU basics. What are cores?
• Make-Use-Of, November 26, 2021: what is a processor core?

And, of course, wiki does it best: link here. But be careful. Even the first line can be confusing. There's a difference between "a" processing unit and "the" central processing unit. 

So, let's go.

In the old days, the computer had one core which no one ever talked about or even mentioned. Maybe there wasn't even a "core" per se. All we talked about was the CPU, RAM and ROM.

The CPU is "the" computer. The keyboard, mouse, screen, speakers are not part of the CPU -- the keyboard, mouse, screen, speakers, microphone, speakers, etc. -- are used to interact with the CPU, or the computer. In a one-core computer, the CPU orchestrates / controls these "things" that allow us to interact with the CPU.

ROM was the firmware that could not be changed; it had the basic instructions for the computer when the "on" switch was flipped. I assume it was embedded in the CPU. It is part of the firmware.

RAM was the changeable, usable software that ran the programs on which you were working at the time. 

"Memory" was the "memory" in the background where stuff was stored until you or your computer needed it. [ROM and RAM are also "memory," but not "memory" like "memory."]

And that was it.

In my simple mind.

And then along came "cores."

Without mentioning the word "core," in the beginning, a "core" was the CPU processing information with its necessary ROM, RAM, and (very limited) "memory." One core. 

One core = one application at a time. Sort of, don't take that out of context.

So, if you wanted to multi-task, you couldn't. You might think you were multi-tasking but you weren't. With one core, your CPU sent information back to RAM / "memory" and retrieved new information from RAM / "memory" to perform a new application, like switching from writing a document to developing a spreadsheet to populating a database.

Back-and-forth, back-and-forth.

The back-and-forth problem was solved with multiple cores, first two cores, and then more.

Each core had its own bit of memory bank and a processing unit. 

So, now, two or more applications could be running simultaneously in the background, unaware of what each core was doing. The user, you, could switch between applications seemingly because the CPU -- the central processing unit -- coordinated all those cores, or better said, coordinated all those individual processing units on each core. The CPU didn't care about all the other "stuff" inside a given core. All the CPU had to do was coordinate what it used to coordinate (ROM, RAM, "memory") but now it had to coordinate the processing units of each of the cores. 

Break, break.

Another way to think about it: stovepipes. 

Remember the concept of stovepipes? Back in the 70's or 80's or thereabouts organizations and businesses and corporations had training sessions with their mid-level managers and "stovepipes" were all the rage, the buzzword. Each stovepipe was a different function in the organization. They were called stovepipes because each entity did its own thing, kept to itself, didn't care -- didn't even know, in some cases - if there were other stovepipes or other entities. Talk about a mess. Upper level management -- the CPU, as it were -- managed, integrated, whatever -- all the various stovepipes. I doubt much has changed.

The computer is a lot like that. Think of each "core" as a stovepipe doing its own thing (or, now, doing multiple things) but all the activities of each stovepipe or each "core" being coordinated, integrated, whatever by the central processing unit -- the CPU. 

So, that's all it is. 

But, wow, now it makes sense. 

From the Apple site, the new 15" M2 Macbook Air, two basic configurations, with the only difference (?) being 256GB SSD storage vs 5122GB SSD storage.

In the old days, the top line would have been simply "M2" or "M1" or "XBY678" but now the chips come in different flavors: different numbers of cores and different types of cores.

A week ago, this made no sense to me. I now understand it -- right, wrong, indifferent -- it's how I see it.

************************
So, How Far Have We Come With Cores?

Links:

• Bloomberg, May 14, 2023: Apple's M3. 
• wccftech, June 11, 2023: Apple's M3. 

The new 15-inch M2 MacBook Air:

• an 8-core CPU and a 10-core GPU

The smaller, cheaper M2 MacBook Air:

• 8-core CPU and 8-core GPU

With the M3 next year:

TSMC’s 3nm N3B architecture may enable Apple to bring major improvements without having to resort to increasing the core count, though we have no way of confirming this.

The exact configuration has not been shared, so we cannot comment on what other M3 variations to expect down the road. However, Gurman shared specifications of the M3 Pro, stating that one version was being tested with 12 CPU cores and 18 GPU cores, but this chipset will only be found in the pricier Macs. 

Think about that. Only two years ago Intel folks said we could get along just fine with one or two cores. Now, we're talking 12 + 18 = 30 cores in a personal laptop. 

Obviously more is better. But, really, how much does one need?

Well, actually, as much as you can afford. We'll talk about that later.

**********************
How Many Cores Are Needed?

How many cores does one need?

Back in 2020, Intel suggested:

My hunch: Apple would have had a different answer.