Does CPU speed matter anymore?
Hi everyone. Leo Notenboom
here for Askleo.com.
I got a question about this.
Let me read part of it.
I've long believed that clock rate
of a desktop mother board was the main essence of Speed/Power.
The system clock, the crystal chip, used to be on the motherboard.
Now that I'm looking for a replacement motherboard, I want one that has at least
the same speed or clock rate as the old one.
But I'm being told by salesman that these days the clock is part of the processor
and to get a faster one, find the relevant processor.
The clock is typically on the motherboard, but regardless of where it resides,
of course you need a CPU that can run at that speed.
So choosing the CPU is not that far wrong.
However, things aren't as simple as they once were.
There are several reasons that that might
not be as important as we might have thought.
So before I dive into this, I definitely want to throw out a caveat
for the pedance around that this is high level.
There are people who are really passionate about this CPU family over this CPU family
or that chipset, this chip set, this Ram, all that kind of stuff.
This is not for you, right?
Pass on this article, pass on this video.
What I'm trying to do here is give a very high level explanation of what the average
consumer needs to worry about, should be paying attention to.
And it's not chipsets, it's not CPU families, not for the average consumer.
If you've got a special need like you're a gamer or a video producer or something
like that, you know that you have other things to worry about.
For the average consumer, that level of detail just isn't necessary.
So in the past, you're not far wrong.
The issue was that, yeah, there was a CPU, it had a clock speed that was controlled
by, as you said, a crystal on the motherboard.
And it was a big deal.
I remember back in the day going from 33 MHz machine to a 66 or 333 to 666.
Those kinds of upgrades were really
impressive and important and really got me excited at the time.
One of the reasons that was so simple
to measure clock speed is that it truly was a system clock.
In other words, that one crystal actually
drove not only the CPU, but many other components on the motherboard.
So if you had a CPU or a clock speed of 33, you upgraded to 66.
Then not only was your CPU faster, but so were many other things related
to its operation, so many other components on the motherboard.
These days things are a little bit different.
For one thing, clock speeds,
at least from what I've seen, kind of sort of leveled off.
On average, I'd say they're usually right
around the 3.2 GHz range, but again, it's a wide range.
The desktop that I'm staring at right now, for example, has a three 5 GHz processor,
whereas the Asclio server is running a two 5 GHz processor.
It's not uncommon for processor speeds to be in those kind of ranges.
That speed is important,
don't get me wrong, but it's not quite as important as it used to be.
A little bit of research lately has led me
to understand that other components on the motherboard that used to be driven
by that single clock in the past, often now have their own clock.
It's independent.
It runs independently of whatever the CPU happens to be doing.
This allows those components to run at speeds that are optimal for them,
independent of whatever is appropriate for the CPU.
So getting a faster CPU doesn't
necessarily mean that you've made other things on the motherboard any faster.
It does mean that your CPU is faster.
That could be a good thing,
but it doesn't have that same global Ramification that it used to.
Now, CPU speed can be very important.
One of the reasons this machine is as
powerful as it is is because when I chose it,
I realized that what I would be doing involved video editing.
Well, video editing is a very CPU
intensive process, which means that I would really benefit
from getting the fastest CPU that my budget would allow.
Hence three five GHz.
Now the Ask Leo server running at two 5 GHz.
It's not really doing as CPU
an intensive job as my desktop is configured for.
Its big job is to serve up web pages on the internet.
Yeah, there's processing involved,
don't get me wrong, but that's not really CPU intensive.
For the most part, even when it's under heavy load,
the CPU is just sort of chugging along, doing what it's doing,
waiting on other things like the network or Ram or the disk.
So understanding CPU speed remains
important, just not as important as it used to be.
Now there are some interesting things that have become more important over time.
One of the things I haven't talked about
these two machines is the number of cores they each have.
It used to be that CPU speed was
increasing fairly steadily for some time, probably in relationship to Moore's Law,
that, like I said, seems to have leveled off.
It seems to have plateaued in that three point something gigahertz range.
What has changed are the number of cores on each processor.
Now, a core in a way is sort of an independent processor.
So when we say we have a dual core
machine, in a sense we have a CPU that's actually got two CPUs inside of it.
We don't refer to those two CPUs as CPUs anymore.
We call them cores.
But essentially they are two independent computers all in one chip.
My desktop machine at 3.5 GHz has 16 cores in its processor.
So it has a CPU chip that has 16 independent cores built into it.
The Asclio server has eight has an eight core processor.
That's something that has increased over time.
Used to be that two and four core were common.
They still are.
But now, as you can see,
as needs increase, more cores are generally available.
There are high end servers that have hundreds of cores in their CPUs.
I can't afford those.
They're expensive.
They're used usually in hosting situations.
But the bottom line is that multiple cores
allow the computer to do multiple things at the same time.
So, for example, there are two ways that multiple cores
typically add a tremendous amount of value.
One is it's rare that we're really only doing one thing at a time.
While I'm sitting here recording this
video, my machine is downloading, email it's updating, web pages.
It's doing all sorts of things in the background.
In addition to getting all of this video and doing something with it,
writing it to disk, multiple cores allow your computer
to literally do multiple things at the same time.
This allows the computer to be very responsive.
If some program is doing something that is
CPU intensive, my machine remains accessible to me.
The other thing is that software can be
written to take advantage of multiple cores.
For example, the video editing software that I use understands multicore machines.
So when I go to produce a video,
it fires up all 16 cores and starts producing video.
That's going to be a lot faster than if it were just using one core.
Regardless of the CPU speed, it requires architecting the software
a particular way, but it does allow the load,
the work to be distributed across the different cores that are in the machine.
Now, it's really, really tempting to say,
okay, great, you've got a three 5 GHz machine and it's got 16 cores.
That means it's the equivalent of a 56 GHz processor.
No, it's nowhere near that simple.
Spreading things across multiple processors takes work.
There's overhead.
Not all software can do it.
The bottom line is that it's somewhere in between.
Depending on what you're doing, it's faster, don't get me wrong.
But it's not simply that mathematically
faster than just multiplying things together.
So the single biggest improvement
in computing speed over the most recent years has not been the speed
of the processor, but rather the number of cores that are placed in the CPU.
Now, there is something else that has nothing else to do with the CPU that I
claim has actually become more important than the speed of the CPU itself.
And that is your hard disk.
What is one of the updates we often
recommend for people to take to one of their older machines?
Replace the old magnetic spinning disk hard disk with an SSD that typically has
dramatic and immediate impact on the perceived performance of the machine.
The fact is, what a lot of us use our
computers for are no longer really limited by the speed of the CPU.
We're limited by the speed of our Internet
connection, the speed of our disk, and so forth.
So those kinds of things end up becoming more important than the CPU speed itself.
Something else to factor in.
I know that it's one of the things
that has made again a dramatic impact on the perceived speed of my machines.
Now, I do want to close this out by saying that absolutely nothing is absolute right.
The point here is that it's not as simple as faster CPU means faster computer.
It really does all come back to one
of my most common answers to just about every question I get asked.
And that is it depends.
It depends on how you use your computer.
Honestly, if all you use your computer for is browsing the Internet,
sending and receiving email, maybe doing some instant messaging,
that kind of stuff, almost any current CPU is going to be fast
enough both in terms of gigahertz and number of cores,
that it's probably not something you need to think deeply about.
I would spend more attention on things like Ram for future expandability,
depending on how many things you try and do at the same time.
I would spend more time on that SSD, perhaps spend more money on that SSD
to make sure that kind of stuff is as fast as it can be.
I'd even advise spending a little bit more
for your Internet connection because a lot of the perceived slowness you might be
looking at is how fast your Internet is able to deliver the bits to your machine.
It doesn't matter how fast your machine is
in any characteristic, if your Internet is slow,
understand how it is you use your machine and then try and map that onto what's
going to be important for your machine when you lay it out.
Bottom line for me is that I do not obsess about CPU speed anymore.
I just don't.
As long as it's within a reasonable range, which most of them are these days,
new machines are, it's not something that I spend a lot of attention on.
Now, again, if you're doing heavy video
editing like I do, or if you're a heavy gamer,
as I used to be, then maybe CPU is more important to you.
But for the most part, again, it all comes back to understanding how you
use your machine and where you want to invest not only your research time,
but your money in the components for the machine you end up getting.
Hope that's helpful.
I hope that gives you a little bit of a direction to go in.
For comments, for updates,
for related links and more, visit askleo.com 14825 three.
I'm Leo Notenboom.
And this is Askleo.com. Thanks for watching.