Cores and Speed

[sethmacbookuser]

I have looked online and I can't find information I'm curious about.

So, if I understand correctly, it used to be the case that all Macs had a single processor. Eventually, they moved to having multiple processors (or cores). My current Mac is about five years old. Its processor is listed as 2.7GHz Quad-Core Intel Core i7. I think this means that it has four processors, each running at 2.7GHz. I'm not sure if the i7 means anything or not (i.e., if it is, for example, just the name of the processor system).

The new, top-of-the-line MacBook Pro has a 2.3GHz 8-core 9th-generation Intel Core i9 processor. It has been awhile since I took a math class, but I'm pretty sure that 8 is more than 4 but 2.7 is more than 2.3. So, to my way of thinking, the new processor in the new MacBook Pro is better in one sense (twice as many cores) but worse in another (each core is slower).

What do I do to make sense out of this? If I understand correctly, then the GHz number is the clock speed. Do I just multiply the clock speed by the number of cores to figure out how fast the computer is? That would seem too easy. And, more to the point, if that's correct, then a new, top-of-the-line MacBook Pro is only 70% faster than a five-year-old model that (I'm pretty sure) wasn't top-of-the-line when I bought it. I thought computer speeds grew faster than that.

So, is there an easy way to think of this? Or, perhaps, can someone direct me to a good, clearly written article on the subject? Thanks.

 

[cal6n]

There's an easy way to make sense of it. Anything with "Intel" in the processor name is pretty much obsolete...

 

[leman]

Ugh, you are in for a ride. There are a few complications here:

- modern processor do not have a single speed, but rather a range of speeds to better adapt to a given situation. The 2.3ghz 9-th gen CPU you mention actually runs up to 5.0ghz or so if you are doing work that benefits from it. The number you see in the marketing material is merely the guaranteed speed that CPU will run if you start demanding work on all the cores simultaneously and keep it running for prolonged periods of time.

- the “speed” (in GHz) is not the same as performance, because different CPUs have different internal implementation and can do more or less work per step. New Apple M1 for example only runs at up to 3.2ghz, but it’s as fast as an Intel CPU that runs at 5.0GHz

- if you want to figure out how fast a CPU is, the simplest thing is to look at popular benchmarks as indicators of performance. They are by no means perfect but they do give one a general idea

 

[ader42]

Yep, on the one hand look to benchmarks for a ballpark speed; on the other hand my mid-range 2014 iMac is approximately half the speed of my top of the line 2019 iMac that cost twice as much.

Computer speeds used to increase more quickly than they have in the last 10 Intel years. The value in upgrading a computer has got less and less. Hence the move away from Intel.

 

[Chompineer]

Clockspeed across architectures isn't directly comparable, it's only really comparable when the chips are the same.

Typically as IPC (instructions per cycle) goes up and node size shrinks, clockspeed goes down, then refinements are made of the architecture or node, clockspeed comes back up.

 

[JMacHack]

So, is there an easy way to think of this? Or, perhaps, can someone direct me to a good, clearly written article on the subject? Thanks.

With any kind of technical question, the answer always depends, especially depending on how in-depth you want to go.

I can try to give a surface level explanation to the best of my ability, but there are a few people in here that are far more technical than me.

1. Clock Speed: think of this like a sprinter, the faster they can run a race, the better. “Base” speed is like jogging, but if you need more speed for whatever reason, there’s “boost” speed, which is faster but uses more energy and makes more heat.

2. Core Count: some jobs can be split into smaller jobs. When a process does that, more cores can be used, and a job will finish faster. But not all jobs can be split up (my favorite analogy being “1woman can make a baby in 9 months, but 9 women cannot make a baby in 1 month”)

3. The annoying “it depends” answers:
So here’s where it gets complex, some processors take more time to do a task, despite having better specs “on paper” you’ll see “ipc” thrown around a lot, think of this like the steps a processor takes to do a job. If a processor has to run through a lot of steps, then it must run faster to complete a job in a certain amount of time, and a processor that doesn’t do as many steps will be able to run slower but complete the job in the same amount of time.

In context of Intel vs. Apple Silicon, the Intel processor must run faster and do much more steps to do the same job an M1 does for a given speed. (Your mileage may vary)

It gets far, far, more technical than this, but I think it’s a basic overview.

 

[dmccloud]

I have looked online and I can't find information I'm curious about.

So, if I understand correctly, it used to be the case that all Macs had a single processor. Eventually, they moved to having multiple processors (or cores). My current Mac is about five years old. Its processor is listed as 2.7GHz Quad-Core Intel Core i7. I think this means that it has four processors, each running at 2.7GHz. I'm not sure if the i7 means anything or not (i.e., if it is, for example, just the name of the processor system).

The new, top-of-the-line MacBook Pro has a 2.3GHz 8-core 9th-generation Intel Core i9 processor. It has been awhile since I took a math class, but I'm pretty sure that 8 is more than 4 but 2.7 is more than 2.3. So, to my way of thinking, the new processor in the new MacBook Pro is better in one sense (twice as many cores) but worse in another (each core is slower).

What do I do to make sense out of this? If I understand correctly, then the GHz number is the clock speed. Do I just multiply the clock speed by the number of cores to figure out how fast the computer is? That would seem too easy. And, more to the point, if that's correct, then a new, top-of-the-line MacBook Pro is only 70% faster than a five-year-old model that (I'm pretty sure) wasn't top-of-the-line when I bought it. I thought computer speeds grew faster than that.

So, is there an easy way to think of this? Or, perhaps, can someone direct me to a good, clearly written article on the subject? Thanks.

First of all, clock speeds are largely irrelevant when comparing processors unless everything else is identical (i.e., a 2.4GHz quad-core Intel i5 will outperform a 2.1 GHz i5 of the same generation and core count). What affects overall performance is a combination of factors: Instructions Per Cycle (how much data is processed with every tick of the CPUs internal clock), core counts, whether or not the processor supports hyperthreading, etc. When comparing the M1 to current 10th and 11th generation Intel CPUs, the M1 benefits from having a wider instruction bus, meaning that it can process more instructions simultaneously than either AMD or Intel. For x86, the practical limit is four decoders due to the complexities of the x86 instruction set, whereas on the Apple side it is almost inifinitely scalable because ARM instructions are fixed-length. To use a car analogy, clock speeds would be roughly equivalent to horsepower in a car engine, as it represents what the engine itself is capable of, but overall vehicle performance depends on a myriad of other factors both internal and external, including transmission, vehicle weight, handling, road and weather conditions, etc.

Where things get ever trickier when comparing different processors both across brands as well as within a single brand is that a lot of this information isn't readily available to the average consumer. There are a lot of people who still ascribe to the "faster is better" mindset regarding clock speed, even though AMD rendered that argument invalid back when they released the Athlon x2 and x4 CPUs. This is because Intel, AMD, etc. placed the focus on clock speeds back when that was the only thing that really mattered and never bothered to correct the mentality once it became part of the picture instead of the whole thing. As far as the rate of growth is concerned, the x86 architecture has hit the upper limits of Moore's Law (which is where these notions of how fast computer speeds increase comes from), so performance increases from generation to generation has slowed drastically.

 

[4sallypat]

There's an easy way to make sense of it. Anything with "Intel" in the processor name is pretty much obsolete...

Agreed!

M1 has blown away any Intel I have had since 2006!

 

[LinkRS]

I have looked online and I can't find information I'm curious about.

So, if I understand correctly, it used to be the case that all Macs had a single processor. Eventually, they moved to having multiple processors (or cores). My current Mac is about five years old. Its processor is listed as 2.7GHz Quad-Core Intel Core i7. I think this means that it has four processors, each running at 2.7GHz. I'm not sure if the i7 means anything or not (i.e., if it is, for example, just the name of the processor system).

The new, top-of-the-line MacBook Pro has a 2.3GHz 8-core 9th-generation Intel Core i9 processor. It has been awhile since I took a math class, but I'm pretty sure that 8 is more than 4 but 2.7 is more than 2.3. So, to my way of thinking, the new processor in the new MacBook Pro is better in one sense (twice as many cores) but worse in another (each core is slower).

What do I do to make sense out of this? If I understand correctly, then the GHz number is the clock speed. Do I just multiply the clock speed by the number of cores to figure out how fast the computer is? That would seem too easy. And, more to the point, if that's correct, then a new, top-of-the-line MacBook Pro is only 70% faster than a five-year-old model that (I'm pretty sure) wasn't top-of-the-line when I bought it. I thought computer speeds grew faster than that.

So, is there an easy way to think of this? Or, perhaps, can someone direct me to a good, clearly written article on the subject? Thanks.

Howdy sethmacbookuser,

You have received a large variety of replies, all with various levels of technical speak. So I will try to give you the non-technical version of the above info . If the Apple systems under comparison are of the same type (Macbook, Mackbook Pro, iMac, etc....) and class (low, mid, high) generally the newer model will offer more performance, irrespective of the CPU nomenclature. Apple laptop/notebook computers have sacrificed thermals for aesthetic (thinness) reasons for years, and Intel CPUs typically are not able to run at its fastest capability for long. This greatly limits overall performance, and (for me) is the most exciting thing about Apple Silicon systems. The new Apple SOCs can operate at their peak performance level far longer than comparable Intel CPUs. MacOS takes advantage of this, as well as the other components of Apple Silicon to make the user experience much better on newer systems. I can't wait to see what they do with the Mac Pro!

Rich S.

 

[profcutter]

Howdy sethmacbookuser,

You have received a large variety of replies, all with various levels of technical speak. So I will try to give you the non-technical version of the above info . If the Apple systems under comparison are of the same type (Macbook, Mackbook Pro, iMac, etc....) and class (low, mid, high) generally the newer model will offer more performance, irrespective of the CPU nomenclature. Apple laptop/notebook computers have sacrificed thermals for aesthetic (thinness) reasons for years, and Intel CPUs typically are not able to run at its fastest capability for long. This greatly limits overall performance, and (for me) is the most exciting thing about Apple Silicon systems. The new Apple SOCs can operate at their peak performance level far longer than comparable Intel CPUs. MacOS takes advantage of this, as well as the other components of Apple Silicon to make the user experience much better on newer systems. I can't wait to see what they do with the Mac Pro!

Rich S.

Yes indeed, that’s an important caveat. In real world performance, when I tested a 2017 MacBook Pro, it was no faster than my 2013. That was a shocker. It was for exactly the reasons you stated: Apple prioritizing thin-ness over performance, and Intel refusing or unable to innovate and move designs forward at a reasonable pace. So given no thermal constraints, the newer intels are faster, but there are indeed thermal constraints.

 

[sethmacbookuser]

Thanks everyone for your replies. I appreciate the different ways people structured their replies (more and less technical, more and less detailed); that really helped a lot. I find this stuff fascinating even though my technical background is limited to what I learned about computer science in high school.

I'm eager to upgrade my MacBook Pro to a model with an Apple silicon chip, but mainly because I'm sick of the butterfly keyboard (replaced twice). If Apple is willing to buy my MacBook Pro back while the keyboard is still working, I will gladly sell it to them. I don't really feel like waiting until the keyboard breaks again. I just want to know how much "faster" or "better" a new product will be (in general) before comparing various models.

 

[leman]

I'm eager to upgrade my MacBook Pro to a model with an Apple silicon chip, but mainly because I'm sick of the butterfly keyboard (replaced twice). If Apple is willing to buy my MacBook Pro back while the keyboard is still working, I will gladly sell it to them. I don't really feel like waiting until the keyboard breaks again. I just want to know how much "faster" or "better" a new product will be (in general) before comparing various models.

From your original post, I assume that you have the mid-tied 2016 15" MacBook Pro with Intel i7-6820HQ/Radeon Pro 450? To give you some perspective, the current M1 MacBook Air is going to be around 2 times faster (both CPU and GPU-wise). If you wait until the Apple Silicon 16" model is released, that one is going to be anywhere between 4 and 6 times faster.

 

[LinkRS]

Thanks everyone for your replies. I appreciate the different ways people structured their replies (more and less technical, more and less detailed); that really helped a lot. I find this stuff fascinating even though my technical background is limited to what I learned about computer science in high school.

I'm eager to upgrade my MacBook Pro to a model with an Apple silicon chip, but mainly because I'm sick of the butterfly keyboard (replaced twice). If Apple is willing to buy my MacBook Pro back while the keyboard is still working, I will gladly sell it to them. I don't really feel like waiting until the keyboard breaks again. I just want to know how much "faster" or "better" a new product will be (in general) before comparing various models.

Howdy sethmacbookuser,

Reading these forums, it would seem that it would be difficult to *upgrade* your MacBook Pro today. There are so many opinions on here, and lots of "facts" presented. But the bottom line is really all about you. WWDC is just around the corner, and it is rumored that Apple could announce/release new MacBook Pros, with specific mentions of a new 16" and 14" model. I suggest you wait until after that, but then just take a look at what you have, and what you want to spend. Apple will allow you to trade your current system in towards a new one, I did that in May of 2020 with my older 2015 15" MacBook Pro (I had the 'mid' model with a discrete GPU).

After the expected WWDC announcement, take a look at what you have, and go match it with the closest option (price, screen size, storage, etc....) currently available, and you will get a nice performance boost. I caution you against downgrading your system at the moment. As of today (27 May 2021), the only Apple Silicon based laptops are the lower-end models. The M1 is an amazing SOC, but Apple is still selling models based off of Intel CPUs in the higher-end range for a reason. In other words if you are looking for an upgrade, don't replace a 15" MacBook Pro with a 13" Apple MacBook Pro or MacBook Air. Don't get me wrong, the current M1-based devices are nice, they are just not intended to replace the 15" MacBook Pro.

IF you do end up with another Intel model, you will be fine for years to come. Apple will certainly warranty your system (AppleCare) for 3 years, and they may even let you extend it beyond that. As long as they warranty it, you know it will be supported.

Regardless if you get an Apple Silicon or Intel model, you will LOVE the new (old) keyboard

Good luck!

Rich S.