What comes after terabytes?
Everyone Leo Notenboom here
for Askleo.com, where the only thing unchanging about technology
is the constant change, terminology being one of them.
Let's have a look at this question.
I feel like I've just crawled out from under a rock or something.
Apparently, Seagate has come out with new drives, with zettabytes of storage.
There are terabytes, which I know this is how I store stuff,
but now there are petabytes and zettabytes in communications with someone at Seagate.
They're telling me that the CIA has
a computer with teraflops of processing power.
I know what gigahertz is, but what is a petaflop?
Or more importantly, how many gigahertz is a petaflop?
Can you even buy this stuff?
Or is this reserved for large companies?
If you could clear some of this up?
I would greatly appreciate it.
Thanks. Yeah.
Terminology, especially around numbers of bytes and speed of computing.
It can get pretty confusing pretty quick.
As I said, it's changing often.
And there are some apples and oranges things going on here as well.
Let's start with bytes,
bytes and more bytes. The size that we're talking about here,
the various zettabytes, petabytes and so on, that you mentioned in the question.
What we're talking about literally is just counting the number of bytes.
A bite is eight bits.
It can have a value between zero and 255.
It is best thought of as a character.
By that I mean a letter of the alphabet or a number.
So, for example,
a word like “supercalifragilisticexpialidocious“
which is an homage to the Mary Poppins fans out there,
would take 36 bytes to store because it's thirty six characters long.
Another measure that I've used in the past
is the Project Gutenberg plain text version of the Bible is five million.
Two hundred and eighteen, eight hundred and five bytes long,
something we will often refer to as a megabyte, which is our first term here.
We often talk about kilobytes which are one thousand twenty four bytes.
A megabyte is one million forty eight
thousand five hundred and seventy six bytes.
But before we go too much further down that path, we need to clarify some
of the terms we're using and exactly what they mean and how we use them.
So here's a table of the terms that we're talking about in the first column.
There's the number of bytes we're talking
about, say a thousand twenty four for a kilobyte or KB. Its magnitude.
I call this an order of magnitude because
it's the way we think of things is about a thousand.
And in fact it is 1024 to the first power.
In other words, just a thousand and twenty
four. The power thing will become important here in a minute.
The controversy or the confusion is
that in fact, the kilobyte technically doesn't mean a thousand and twenty four.
Technically, it means a thousand,
which is one of the reasons things like disk space, for example,
can be represented as one thing when it's actually another.
When I say Kilobyte am I meaning
a thousand and twenty four, am I meaning a thousand?
Depends on the context.
The correct name is a kibibyte with a B instead of an L, that's 1024.
No confusion, but and I won't go down the rest of that column.
But if you need to be very specific
and with no chance for misunderstanding, then gigabyte is what you want to mean.
A thousand and twenty four.
Like I said, in reality, in practice, the kilobyte is what we tend to use
in the computing context to mean a thousand and twenty four.
And from a conceptual point of view, you and I tend to think of it as about
a thousand about gets a little bit more inaccurate the further we go along here.
So we've talked about a megabyte one
million forty eight thousand five hundred seventy six bytes.
Its magnitude is a million and it's a thousand twenty four bytes squared.
So it's a thousand and twenty four times
a thousand twenty four or a thousand and twenty four to the second power.
A gigabyte roughly a billion bytes is a thousand and twenty four to the third
power, a terabyte, which is a trillion bytes.
And that's probably the largest one you're seeing on hard drives right now.
And it's a thousand and twenty four to the fourth power.
Now, the terms that are on the horizon,
the terms that you were asking about, these are the terms we're going to start
slowly seeing more and more of as disk capacities continue to increase over time.
The petabyte is a.
Quadrillion bytes, the exabyte is a quintillion bytes,
a zettabytes sextillion bytes and a Yottabyte, a septillion bytes
or a thousand and twenty four to the eighth power.
So you can see in this table exactly what those numbers mean,
that the left hand column will show you literally what these numbers mean in terms
of decimal numbers that you and I might read.
You notice I stopped trying to read them because they are just too long.
But these are the terms that are coming after terabyte.
These are what they mean.
And conceptually,
this is the order of magnitude you should be concerned with when you're actually
just sort of thinking about how big these things are.
So as I record this,
the largest drive I can find online for personal use, in other words,
something that I could buy from my own computer here is around 18 terabytes.
That's not uncommon.
I kind of sort of expect things to get bigger over time.
And to be clear, that is a traditional
spinning hard disk magnetic media type of disk.
The largest SSD.
Right now, I'm told, is around eight terabytes.
It's also fairly expensive.
More commonly, for example,
the ones I've got installed in my machine are like a couple of terabytes.
That's about where the price starts
to make sense for an individual machine such as this.
If you do have lots of cash and I mean lots and lots and lots of cash.
Yeah, there's supposedly a 100 terabyte SSD out there.
I have no idea why you would want it right now.
Eventually we'll probably all have machines with them,
but they won't be 40000 dollars apiece when the time comes that there are larger
drives in development is kind of a given right.
The technology folks, the scientists behind all this hardware,
they're always working on packing more bits into a smaller space.
And that's kind of sort of where this is headed.
The question, of course, is, as always is how fast will that happen?
I don't know. You could talk about Moore's Law.
You could talk about some of the other laws related to capacity.
The bottom line about the only assumption we could really make is that our current
size disks will get cheaper and larger disks will become more common.
And that's just sort of a constant thread
of change throughout this industry since its inception.
That's pretty much disk space.
I do want to say, since you mentioned it specifically.
I'm not seeing zettabytes anytime soon
and probably not in my lifetime, that's a lot of bytes.
I will also say that a lot of the stories you hear about at large data centers,
facilities and so forth, even if they are connected to one
computer, one PC, one server, they're generally not one disk.
More often than not, they are arrays, sometimes arrays of many, many,
many different disks or many, many different instances of the same disk.
So, for example, you might find
a data center server with one hundred and eighty terabytes.
But what they will have is 10 18 terabyte drives.
That's typically the most cost effective way to get that kind of storage.
And there's also some redundancy of error,
recovery and resiliency built into designing that way instead of putting
all of your bytes on a single disk, that's disk space.
Now we have to talk about flops and Hertz.
This is about speedflops.
And Hertz are, in fact, two different ways to measure speed.
They are, I'll just say, loosely related.
There is not a conversion from one to the other.
And we'll see why that is in a minute.
Hertz is the speed at which the processor
runs based on a signal that is given to the processor.
It's kind of like how quickly you might turn the crank to make an engine go.
You can turn it fast or you can turn it slow, depending on what kind of an engine
it is, what its ability to handle that speed is.
But the idea is that, you know, a one gigahertz processor,
it is performing one billion simple operations per second.
Now, a billion operations per second is a lot,
but it's less these days a measure of the number of operations as it is just
an order of magnitude for the speed of the chip.
The issue is that integer operations like adding one plus one
and doing that four billion times, as you might, for something I don't know,
that is a very simple operation and might very well take just one clock cycle.
You might be able to do a billion of those in a second.
The problem is that there are operations that take more than one clock cycle,
and because of the way processors now try to aggressively optimize what they're
trying to do for you, they're kind of looking ahead.
What kind of instructions come next?
Can they get ready for that instruction
before it's actually time to run that instruction?
They can actually do some operations kind
of in parallel, which means that while, yes,
each operation takes one clock cycle, if you're doing two of them,
kind of sort of at the same time, the average might be less.
So it's no longer really a true measure
of exactly how fast the processor can perform individual operations,
but it remains a measure of just how fast the processor is
FLOPS.
A Flop is actually an acronym kind of for floating point operations.
Now, so far I've been talking about simple
operations, integer operations, whole numbers between one and four
billion, for example, would be one way of looking at them, adding one in one.
Very simple, right.
It's the kind of a thing that in binary is very, very, very simple to do.
Floating point numbers are numbers with decimal fractions.
So three point one is a floating point.
Number three point one four one five nine two six five three five eight nine
is another very familiar floating point number.
These are stored differently than integers
and the operations to actually manipulate
floating point numbers are significantly more complex and I mean
more complex at a computational level at the processor level.
So floating point operations are important, an important measurement
for a lot of different types of computer use, because a lot of scientific work,
a lot of of all sorts of different things actually rely on floating point numbers
rather than just doing everything in simple integers.
So FLOPS is a very important measurement
for exactly how fast a computer might be in those kind of applications.
The reason there's not a simple conversion
is because the implementation of how a processor actually performs floating
point operations varies from one processor to the next one.
Might be a very complicated and expensive
processor able to perform floating point operations extremely quickly.
One might be a less expensive processor, but one that might be used less power,
be more appropriate for a laptop, whatever it can still do,
floating point operations, but it can't do them as fast as the other one.
So the underlying processor architecture
makes a huge difference to exactly how fast floating point
operations can happen on that specific hardware.
So you'll never see a general conversion between gigahertz the clock
speed that the processors running at and the speed that a processor might be
able to perform floating point operations for one processor or one processor family.
There might be a number, there might be a conversion,
but it's not something that would hold true of all processors.
And it's not something that, as it turns out, is particularly useful
because you really are comparing apples and oranges in situations like that.
You mentioned the petaflop in your question.
That is nothing more than a quadrillion
floating point operations per second, much like kilobytes and megabytes
and terabytes and gigabytes and all those kind of other bytes.
That same prefix, meaning a thousand or a million or
a billion, also can get applied to flops or even herts.
So you end up with petaflops, meaning a quadrillion floating point
of operations per second or gigahertz, meaning a billion clock cycles per second.
If you're interested in something deeper
on FLOPS, specifically because it is very deep and very interesting technology,
the Wikipedia article on FLOPS actually has a fair amount more information
and there's a link to that in the article that this video is based on.
As I said, I hope this was helpful.
It hopefully clears up a little bit of the terminology,
at least with that table, you can see what kinds of terms mean,
what kind of magnitude, and you can see what's coming next
for updates, for related links for that table.
For the original article in which this video is based, visit askleo.com/131697.
I'm Leo Notenboom. This is.
Askleo.com, thanks for watching.