Processors that can process 32 bits or 64 bits are known as which type of processors?

32-bit vs. 64-bit processing

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- You know, it's always fun to look at the bottom of a CPU. It's got so many little wires or little pad contacts. On modern CPUs can be over 2000 of these little connectors. And you always wonder, why does it need so many connectors? Based on other episodes, we've learned stuff like the external data bus, which is going to be in our examples, we only used eight wires. And I'm sure set one of these is probably a clock wire, and a few of these are probably voltage and a few of these are ground. But why so many wires? Well, I'm going to add to the list here a little bit and talk about something very important. We know that the CPU has to grab lines of code from RAM. The question is, how does it do it? It's actually really fascinating. Let me show you. So here's my CPU. Now the CPU has an external data bus, in this case, I'm just going to say it's an eight bit external data bus. There are a lot bigger today, but this will get us started. Now that external data bus doesn't just come out of the CPU and end, it extends throughout our computer. In fact, that's the job of a motherboard. Its job is to allow lots of different peripherals, hard drives and things like RAM, to also connect to the CPU. So let's take a look for a moment. And let's take a look at some RAM. Now in the real world RAM looks like a stick like this. However, electronically RAM looks very different. RAM looks like a one column spreadsheet. In each column of this spreadsheet, you can store eight binary values or a bite. So the number of different rows we have in here is going to depend on something which I'm about to explain to you. So the challenge we have here is, I've got the CPU over here, and I've got all of these lines of code. How can I get individual lines of code on to the CPU so that it can run it and do whatever it needs to do? Well, to do that, we're going to add another chip. This chip is known as the memory controller chip. Now, memory controller chips used to be a separate chip. However, today they're pretty much all built into the CPU itself. But for right now, let's just go ahead and keep him as a separate chip and we're going to give him eight wires to connect to the external data bus as well. All right, now, once we got this, the memory controller chip in essence kind of has a claw built into it, and this claw can grab any single byte of memory and put it on the external data bus, and then it gets sent to the CPU, and then the CPU can execute it. Sounds great, right? So the problem we have here is how can the CPU tell the memory controller chip, which one of these rows which byte of RAM does it need to be dropped onto the external data bus so it can execute it? Well, the secret is something called an address bus. And address bus is a direct connection between the CPU and the memory controller chip, that isn't used to move data, it's simply use by the CPU to tell the MCC which byte of memory it needs right now. If we want to understand how an address bus works, we need to think in terms of binary. So let's pretend like I have one wire running from the CPU to the memory controller chip in this new address bus thing I just mentioned. That wire can be in one of two states, it can be either off or on right. So what we could say is that with a one bit address bus, we could address up to two different bytes of RAM, we could have two separate commands, and if it was off, it would grab the top one, and if it was on we grabbed the second one. So that wouldn't be very useful if we only had two bytes of RAM and a computer, so we probably need a few more wires, right? Well, let's add a few more and watch what happens. Okay, in this particular example, what I'm going to do is I'm going to run 16 wires from the CPU to the memory controller chip. These 16 wires are not used to move data, they're just for the CPU to talk to the memory controller chip, to tell it which row of memory it wants to access at any given moment. So if it's all turned off, that's 16 zeros, that's going to be the first byte of memory. And if they're all turned on, that's 16 ones, that's going to be the last one. So what we have here is to the 16th power, or 65,536 bytes of RAM. Now that may not sound like much, but back in the day of the 16 bit address bus, that was crazy. So simply by putting different patterns of ones and zeros on the address bus, the CPU can order the memory controller chip to grab individual rows of RAM so that we can run the Program. Now 16 bit didn't last too terribly long. For a long time we had 32-bit address buses, and today we have 64-bit address buses. So a 32-bit address bus can address around four gigabytes of RAM, and a 64-bit address bus is such a huge here. Just put it up there. If you have 32 wires on an address bus, that means you can address to to the 32nd power, or about four gigabytes of RAM. Now, 32-bit addressing worked great from the mid '80s, up until around the early 2000s. So 32-bit was extremely popular. However, if you talked to people today about how much RAM they have in their computer, you're going to hear people say things like, "Well, I got eight gigabytes of RAM or 16 gigabytes of RAM." That means that they have to have CPUs that have more than 32 wires. And what we see today on the vast majority of CPUs out there is they have 64 wires on the address bus. And 64 wires allows the address ability of up to it's a really, really big number, write it down and get it for me 'cause I can never memorize such a big number. So with 64-bit processors, we can address a lot more memory. If you put say eight gigabytes of RAM, in a system with a 32-bit CPU, it will only see four gigabytes, it will never use more than that, it doesn't have enough wires, so it's just not going to happen. So the whole 32-bit versus 64-bit world well, it's not as big of a deal as it used to be because 64-bit has become so common. There's a couple of things I want to mention first of all. Number one, almost every 64-bit CPU on earth, can run 32-bit stuff if needed. It would prefer 62, but it can run 32. So that's an important thing to keep in mind. When in doubt, you're probably going to have a 64-bit processor. In terms of desktop CPUs, I haven't seen a dedicated 32-bit processor in many, many years. But we do mention this on the exam, so I want to cover it. One of the things I want to show you is if you're going to have a 32-bit or 64-bit processor, you're going to have to install the correct operating system to make that work. So I've got laid out here some installation media that I'd like you to take a look at, and it literally will show you whether it's a 64-bit or 32-bit version of Windows. Let me show you what I mean. What I've got here is a number of different versions of Windows I got an old copy of Vista here, this is Windows 10 down here is Windows 8.1. What i want you to notice more than anything else, this is a 64-bit version of Windows, this is a 32-bit version of Windows. This is a 64-bit version of Windows, So for years, so you had to be really careful, if you had a 64-bit processor, you made sure to get a 64-bit copy of Windows. if you had a 32-bit processor, you got a 32-bit copy of Windows. Modern installation media will literally query your system, and if it's a 64-bit processor, it'll install 64-bit, if it's a 32-bit processor, it'll install 32-bit. And you can actually if you look very careful there, you'll see that it says 32-bit 64-bit. So that's telling us that this particular installation media which is just a thumb drive by the way, if I plug this into a system to install Windows, if it sees I got a 64-bit processor, boom, it'll just go ahead and install it. 64-bit gives us a lot of advantages, the biggest one is more memory. And that's really in and of itself enough for us to want to install it. Four gigabytes of memory on a system today is pretty small, but it can still happen. So now the question is okay, I don't know what I have on my computer, how can I tell? Every operating system will let you know what version of operating system you have on it, the 32-bit or 64-bit. If you take a look at the screen right here, here in Windows, if you take a look right here, it says system type 64-bit operating system and it's an X 64 based processor. When we talk about processor types, when you see the term x 86 that means it's a 32-bit processor. When you see x 64, that means it's a 64-bit processor. So it's easy enough to be able to quickly recognize whether you have a 64-bit version of Windows or a 32-bit version of Windows. So now the big problem that comes into play are the actual applications, because if you got a 64-bit version of Windows, you probably want to 64-bit version of the particular application. So when we're dealing with applications, take a look on the screen right here. This is CPU-Z and you'll see that when I download it, downloads both a 32-bit and a 64-bit version. And here's some other utilities and you'll see they all do 32-bit and 64-bit versions. If you had a 32-bit operating system and you installed or at least tried to install a 64-bit application, you're not going to break anything, the installation simply going to go, "Mmh," this isn't going to happen and it stops here. So there's no damage and trying. However, in the opposite direction, it will work. For example, if you have a 64-bit version of Windows, you can install 32-bit applications. So Windows is actually designed to handle this. If you take a look in Windows, on the C drive right here, you'll see you have two folders, this folder called Program Files, this is for 64-bit Programs. This folder here called Program Files x86, remember, x86 means 32-bit, will actually install 32-bit Programs. If you install a 32-bit Program on a 64-bit system, that application cannot use more than four gigabytes of RAM. So, for example, this happens all the time, in office 365 for example. Here I got office 365 running, okay, there's my account. But if you take a look right here, But if you take a look right here, you'll see right up here, you'll see right up here, it installed it installed a 32-bit version of Word. a 32-bit version of Word. This sort of had me scratching my head a little bit. So I've been scratching my head a little bit, I was like, all of these programs I was like, "All of these Programs should be able to install should be able to install the 64-bit version the 64-bit version, of I've got a 64-bit processor." if I've got a 64-bit processor And the answer actually to look this up, and the answer, I actually had to look this up, came from Microsoft and Microsoft said came from Microsoft. And Microsoft said, "We feel that the 32-bit version we feel that the 32-bit version is better for compatibility. is better for compatibility, like people have add ons Like people have add-ons in their Excel spreadsheets in their Excel spreadsheets and stuff like that." and stuff like that, and that for compatibility reasons, And that for compatibility reasons Microsoft by default, Microsoft, by default, installed a 32-bit version of Office, installed a 32-bit version of Office, even though I have a 64-bit processor. even though I have a 64-bit processor. In fact, to install 64-bit office, In fact, to install 64-bit Office, I had to dig a little bit I had to dig a little bit to actually find the 64-bit installation. to actually find the 64-bit installation. So, this is the big difference between 32-bit and 64-bit. So this is the big difference between 32-bit and 64-bit. If the world is all 64-bit, If the world is all 64-bit, then why we're even talking then why are we even talking about 32-bit, Mike? about 32-bit Mike? Is this Ancient Taters? Is this ancient taters? Well, it's not. Well, it's not. 32-bit is alive and well in a lot of systems. 32-bit is alive and well in a lot of systems. For example, this little Raspberry Pi right here For example, this little Raspberry Pi right here, is a 32-bit system, is a 32-bit system. and if I want to install a Linux operating system on here And if I want to install a Linux operating system on here, and I do, it's pretty common, and I do, it's pretty common, I'm going to make sure I'm going to make sure to get a 32-bit version of Linux to get a 32-bit version of Linux so that the system so that this system can handle it. can handle it. So there's absolutely nothing wrong with 32-bit, So there's absolutely nothing wrong with 32-bit, just keep in mind that in today's world just keep in mind that in today's world, it's a little bit more specialized it's a little bit more specialized, and you're going to be seeing it more and you're going to be seen it more on individual systems on individual systems than on the regular big desktops and laptops than on the regular big desktops and laptops and even most of the smartphones we use today. and even most of the smartphones we use today. (funky music) (soft orchestra music)