[Music] welcome to another video from explaining computers this time i'm going to explain the hardware inside a desktop pc this includes its motherboard which is fitted with a processor cooler memory an ssd or hard drive and sometimes a separate graphics card mount all of these in a case and add a power supply and various cables and we have a desktop computer but we put this one together rather quickly so let's take everything apart so i can explain pc hardware in more depth inside all desktop pcs we find a main circuit board or motherboard to which all other hardware is connected many pc components insert directly into a motherboard socket and in most desktop pcs this includes the central processing unit or cpu this is the hardware that actually runs computer programs and is secured in place by a retaining mechanism the speed of a cpu is measured in gigahertz with most modern processors having a speed of 2 gigahertz or more because modern micro microprocessors execute billions of operations per second they generate a lot of heat they therefore need to be fitted with a cooler which is usually a metal heatsink and a fan and as we can see when fitted the cooler completely hides the processor from view in addition to a processor all computers require some random access memory or ram this is a form of temporary or volatile storage into which programs and data are loaded when the system is running ram modules are normally inserted into dim or dual inline memory module slots with most motherboards having two or more dim slots that are arranged into one or more banks today at least four gigabytes of ram is required to successfully run a modern operating system with 8 16 and 32 gigabytes of ram being common in a modern desktop pc as the contents of ram are lost when power is removed all computers require some non-volatile storage to retain their operating system applications and user data when they're switched off for this purpose a desktop pc will be fitted with at least one solid-state drive abbreviated to ssd or a hard disk drive otherwise known as an hdd ssds store data on non-volatile memory chips whilst hard drives read and write data to spinning magnetic plutters the capacities of ssds and hard drives are measured in gigabytes and increasingly terabytes with a modern pc usually having a main or system drive at least 250 gigabytes in capacity whilst hard drives are slower than ssds and are less robust they do cost less per gigabyte it's therefore not uncommon for a pc to have an ssd as the system drive on which its operating system and some programs and data are located as well as a much larger capacity hard drive for the storage of games videos or other very large data files some desktop pcs are also fitted with an optical drive for reading and writing cds dvds and possibly blu-ray discs although this is becoming less common traditionally as we can see here optical drives hard drives and ssds have been fitted in bays or cages located at the front of a desktop computer's case several different interfaces can be used to connect drives most modern pc motherboards have a bank of satter or serial ata ports and these can be used to connect a hard drive optical drive or ssd via an appropriate cable however many modern motherboards also have one or more m.2 slots into which an ssd can be inserted and retained with a screw indeed increasingly many desktop pcs are fitted with an m.2 ssd as their system drive note that m.2 ssds come with either a sata interface or a faster form of data connection known as mvme which stands for non-volatile memory express in addition to processor and ram sockets and m.2 and sata ports pc motherboards feature a whole host of other components and connectors these include the motherboard's chipset which in modern pcs is a single integrated circuit that helps the processor to communicate with many of the computers other components and peripherals like the cpu the chipset requires a heat sink under which it's obscured from view to receive electricity modern motherboards have two atx power connectors that hook up to their power supply somewhere on the motherboard there will also be a small battery that retains the time and sometimes other settings when the computer is turned off rotating to the left edge of the motherboard we find a range of connectors that protrude from a desktop pc's back panel these include an ethernet port for a wired network connection as well as usb ports for connecting external storage and other devices the computer's keyboard and mouse are usually also connected to usb ports although legacy ps2 mouse and keyboard sockets are still found on many desktop pc motherboards in addition there will be audio jacks and some combination of hdmi vga and displayport for connecting a monitor if the pc does not have a separate graphics card talking of which south of the processor and ram sockets a desktop pc will have one or more peripheral component interconnect express or pcie slots these can be fitted with many different kinds of expansion card the most common of which is a graphics card this contains a powerful gpu or graphics processing unit and is necessary in a pc that is used for high-end gaming or to run the most demanding video editing and related applications finally to have an operational computer we need to add a power supply and ideally a case this typically has removable side panels to facilitate maintenance and upgrading and is usually fitted with one or more fans to assist with cooling so if we now put on the side panels and add a monitor keyboard and rodent we have a fully functional desktop pc all ready to watch an explaining computer's video in the 1980s and 1990s desktop pcs changed the world today many people are more likely to use a laptop or a tablet or a smartphone for many of their computing activities but these are still based on the same kind of technology they all have a processor and memory and storage and so if you want to understand computer hardware a desktop pc is still a good place to start but now that's it for another video if you've enjoyed what you've seen here please press that like button if you haven't subscribed please subscribe and i hope to talk to you again very soon [Music] you