Motherboards, PC Cases, Power Supplies

MSI K8N Diamond Plus Socket 939 motherboard with two SLI PCI Express slots
MSI K8N Diamond Plus Socket 939 motherboard

Introduction to the desktop PC motherboard

You must know as much about motherboards (aka mainboards) as possible in order to be able to understand how a desktop or laptop PC is configured and functions. The image above shows an MSI K8N Diamond Plus motherboard.

There are only four major manufacturers of motherboards that you should consider buying for a self-build PC or upgrade – Asus, Gigabyte, MSI and ASRock. Note that the major brand-name PCs – HP, Dell, etc. – often use proprietary components, including the case, that cannot be upgraded using standard components that can be used in any ATX or mATX case.

The specifications provided by seller websites, such as Amazon, often do not provide all of the information that purchasers want to know. To find the missing information means having to find and read the reviews for a particular make and model of motherboard.

.The micro-ATX form factor (m-ATX), means that the motherboard is a reduced-size ATX motherboard. For example, it only has enough space to provide two DIMM memory slots instead of the four slots that a full-size ATX board provides. A recent mATX board usually only supplies a single slot for an M.2 NVMe SSD drive. Some full-sized ATX motherboards, such as the Gigabyte H370 HD3 model, provide four RAM DIMM slots and two M.2 NVMe SSD  slots that use the super-fast PCIe bus that is four times faster than the SATA bus. (In short, SATA SSDs are redundant.)

The size of the ATX motherboard is 12 × 9.6 inches (305 × 244 mm). Note that there is an ATX form factor called EATX, the motherboard of which is 12 x 13 inches. An EATX board provides an extra two inches on its right side for additional expandability. EATX motherboards are usually  used in servers because they require extra hardware compared to a desktop system.

Gigabyte H370 HD3  ATX (rev. 1.0) specifications –

Note that motherboards come with 1, 2, or three M.2 slots. The slot can support  both SATA and NVMe SSD drives. Check the motherboard’s user manual to find out what the board supports. You download it from the motherboard manufacturer’s website, under the Support heading.

The Gigabyte z390 Aorus Master motherboard comes with three M.2 slots. Here is a forum thread that deals with a question about the M.2 slots.

The images below show an ATX case with a transparent side and an ATX motherboard installed in an ATX case. An ATX case can accommodate a micro-ATX motherboard.

An ATX desktop PCcase with a transparent side
An ATX desktop PC case with a transparent side
An ATX motherboard installed inside an ATX PC case
An ATX motherboard installed inside an ATX PC case. Click on the image to see its full size

Motherboard user manual

Desktop PCs mostly use ATX and micro-ATX (mATX) motherboards. mATX boards are cut-down ATX boards that have less support for components than the full-size ATX boards. For example, an mATX board usually has only two RAM memory slots instead of four and have only a single PCIe  x 16 slot for a graphics card. The mATX boards fit into any size of ATX case. If you want maximum expandability, go for an ATX board.  The mATX boards are usually less expensive than ATX boards.

The motherboard manufacturers provide a user manual for each model that comes with a new motherboard. It provides all of the information on that make/model of board, including how to connect the power supply, install the internal components, such as the RAM memory, processor, drives, etc.

If you buy a brand-name PC you need to identify the make/model of its motherboard in order to obtain a user manual from its manufacturer’s website. Alternatively, you can use a free tool, such as the Belarc Advisor or CPU-Z or Speccy.

The link below provides the download page for the motherboard of the Asus Sabertooth X99 Intel Socket 2011 motherboard. Choose the language you want to download the file in the PDF format that requires a free PDF document reader. You can save it to read at your convenience.

Motherboard connection ports for peripheral devices

The image below shows the connection ports of an Asus F1A75-V Pro Socket FM1 motherboard from 2011 that appear at the back of the case and the devices they connect, including the built-in audio ports used by the motherboard’s sound chip.

Asus F1A75-V Pro Socket FM1 motherboard’s ports panel showing the in-built ports
Asus F1A75-V Pro Socket FM1 (2011) motherboard’s ports panel showing the in-built ports. Click on the image to view its full size

In March 2017, the Asus Prime X370-PRO motherboard has no USB 2.0 ports. There is a single USB 3.1 Type-A and a single USB 3.0 Type-C port. The HDMI port of the board from 2011 is replaced by an HDMI 1.4b port on the 2017 board. Another improvement are the LED indicators on the LAN port that indicate activity (Off – no link – Orange – linked – Orange blinking – data activity) and connection speed (10 mbps – Off – 100 mbps – Orange – 1gpps – Green).

Ports panel of an Asus Prime X370-PRO motherboard (2017)
Ports panel of an Asus Prime X370-PRO motherboard (2017). Click on the image to view its full size

Motherboard specifications

The speed (frequency) of PC processors is now measured in GHz (gigahertz). Note that anything measured in Hz (hertz) or MHz (megahertz) or GHz is measuring its frequency, not its speed – the term that is often used instead of frequency. In electronics, when the frequency is increased, the electronically generated wave pulse isn’t actually going any faster – it always approaches the speed of light – it is just able to carry more data, because the wave is compressed as the frequency of the wave increases. There are more up and down cycles per metre, so the higher the frequency of a wave, the more data it can carry, in much the same way as compressed print can place more data on a page. Note that the design of the processor is just as important in determining its operating speed as its frequency. For many years, AMD processors operated at slower frequencies than Intel processors, but came close to Intel’s operating speeds by having more efficient designs.

In all desktop PCs that have a standard ATX or micro-ATX PC case, the two most common sizes, you can replace or upgrade the motherboard, but you cannot buy new laptop motherboards from computer shops – retail high street shops or online stores.

The miniaturised motherboards used in laptops provide most of the same features as desktop-PC motherboards but usually have fewer ports of any one kind due to the lack of space from which to provide them.

The type of motherboard being used by a particular kind of computer is designated by its form factor. All of the form factors are dealt with on this website –

The main form-factor motherboards in use are ATX and micro-ATX that are fitted into mini-tower (aka micro-ATX), midi-tower and full-tower ATX cases. Both full ATX and micro-ATX motherboards are powered by ATX power supply units (PSUs).

Mini-ITX motherboards are used in mini PCS and housed in small ITX and mini-ITX cases. These PCs have very limited upgrade potential due to the small size of the board. The processor is usually soldered into the board instead of being fitted into a socket and so can’t be replaced in the usual way of taking the processor out and putting a new one in. Someone with soldering skills could probably replace the processor.

Below is good video showing a mini-ITX case and motherboard PC build. It provides plenty of tips. Employs an ASUS ROG Strix B460-I Gaming (WiFi 6) B460 LGA 1200 (Intel 10th Gen) Mini- ITX SFF Gaming Motherboard.

NZXT 210 Mini ITX portable computer build –


Currently, PCI (old technology still in use) and PCI Express slots on the motherboard are used for adapter cards – graphics cards, sound cards, network cards, etc. The PCI standard has been in use for several decades now and is still in use, but the PCI Express standard is used for the latest graphics cards. The PATA IDE standard used to be used for hard-disk and CD/DVD drives, but it has been replaced by the SATA standard, which has reached version 3.2 (Sept. 2014). Internal hard-disk and optical CD/DVD drives work perfectly well using a motherboard’s SATA and SATA 2.0 ports. They work on but can’t use the maximum data transfer speeds provided by the SATA 3.0 standard, which can only currently be used to the full by SSD drives. SATA is a backward-compatible standard, which means that a device designed for a higher version will work on a lower version but only at the lower version’s data-transfer speed.

Visit the following Wikipedia page – Serial ATA – for the latest version information on the standard –

You should always make sure that a power supply that is provided with a case or a new PC desktop is a quality unit capable of delivering its stated maximum power output (400W, 500W, 600W, etc.). If you install, say, a 1000W unit and the components only need, say, 600W, they won’t use any more than 600W because the power supply is capable of providing 1000W.

Most PC cases bought new don’t come supplied with a power supply unit (PSU) and when they do it’s usually not one worth having. I am fond of the Corsair brand of case and power supply. They are not too expensive and are usually very reliable. If you are going to buy your own power supply, you don’t have to spend a fortune on a case, just buy one that can accommodate the components that you intend to install in it.

The power supply unit installed in inexpensive PCs and cheap cases is almost always a cheap, low-quality unit that should be replaced for the good of the computer, which can be destroyed if the power supply packs in. Cheap power supplies are also a fire hazard. To find out the make/model of power supply requires opening the case and reading what is written on it. You can then use the make/model as the search term to conduct a web search. I would advise doing that as soon as you receive a new desktop PC regardless of its cost, just in case a cheap power supply is installed. An expensive PC might have originally have had a quality unit that was replaced by staff working at the store with a cheap unit.

Useful information on motherboards on the web

Micro-ATX motherboards are smaller than full-sized ATX motherboards used in most desktop PCs and so cannot provide as many adapter-card or RAM-memory slots, can be installed in any ATX case, but are usually installed in mini-tower ATX cases. A full-sized ATX motherboard is too large to be installed in a mini-tower (micro-ATX) case.

How To Choose A Motherboard: A Guide For Beginners –,review-33048.html

ATX [form factor] –

Reviews of ATX PC cases –

Reviews of power supply units (PSUs) –

The cases and PSUs reviewed above, tend to be expensive. Amazon is always a good site to visit for PC components because the prices and the purchaser reviews are good. You can do further research on the web for any make/model that appeals to you.

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