How To Choose A Motherboard

While the processor, graphics card, and even the RAM speak directly to questions around performance, the motherboard will answer the more fundamental question of what you can run on your PC. Hardware compatibility centers around the motherboard, because it is the body of a PC, into which all other parts must fit.

As recently as ten years ago, demanding software (whether business titles or games) often needed all components to meet very specific minimum requirements in order to run properly. You chose those parts, then tried to find a motherboard that was compatible with all of them. That's rare today. Pick a program, any program, and regardless of what the benchmarks say, almost any motherboard will accept parts fast enough or big enough to run that software well.

Motherboard selection priorities can be summed up in four expressions, two of them related: size, cost, longevity and future-resistance. The cheapest Intel H81 or AMD 760G board, outfitted with the appropriate CPU, graphics card and memory can make any game that needs a single graphics card functionally as enjoyable as a top-dollar Intel Z170 or AMD 990FX motherboard, even though there will certainly be a few frames per second performance difference between them.

The big difference will be what happens in two or three years. If you want a second graphics card, the H81 and 760G boards won't help, and if overclocking the CPU becomes essential, the H81 will say “Overclocking? What’s that?” and the 760G may simply die trying. If you can anticipate your future needs as well as your current requirements, you can select the right motherboard. Check out the number and type of expansion slots. How many USB ports are available? Is the onboard sound good enough, and if not, is there a place to add a decent sound card? Can I plug in all my drives? Can I make the CPU run faster than factory specifications? Safely?

Some of these questions can be answered just by looking at the size of the board.

Form Factor

Every PC ever built goes somewhere. Maybe it’s on the floor or on top of a big desk, but it might be in a rack, on a shelf, share a [small] desk with other accoutrements of a typical office worker, or be placed somewhere that puts practical limits on size.

Here are the most common form factors. As you can see, each of them has a different number of expansion slots, into which cards such as display adapters, wireless NICs, and tuner cards can be inserted. The EATX form factor is deeper than ATX, but adds no additional slots. If you know you need a graphics card, professional-quality sound card, and plan to re-use a wireless NIC, then Mini-ITX and DTX are not for you. If it needs to fit in an alcove of a desk, then ATX (or EATX) may not be viable options.

Layout Considerations

Let’s take a look at a typical higher level motherboard for an example of connector and port types.

Here we see some common port and connector types. Of course, not all boards feature all types, and some components may be located differently. Just as some PCIe slots may be wired for fewer lanes than the slot length suggests (or have some lanes disabled depending on what other slots are in use), the M.2 connector at (6) in the diagram above may have up to four PCIe 3.0 or 2.0 lanes in it, or it may have one or two SATA ports in it, or a combination of these interfaces.

Here, we see some PCIe slots. Top to bottom, they (and their most common usages) are X16 (for graphics cards), X8 (also for graphics cards when more than one is used), and X4 (RAID cards, PCIe SSDs). In addition, even shorter X1 slots are more commonly available, for wireless NICs and port expansion, including USB, SATA, and legacy port types.

In the example above, notice that the forward (right) end of the smaller slots are not enclosed. Most PCIe cards should work in open-ended slots with fewer PCIe lanes than the cards possess, but the performance penalty may be severe. Also, on all but the most advanced chipsets, only the primary PCIe x16 nearest the CPU will electrically possess all 16 pathways. Secondary and tertiary slots may be wired as x8 or x4. Nvidia will not allow an X4 slot to be used for a second graphics card in SLI, and Crossfire performance of multiple AMD graphics cards may take a performance hit, especially if the slots are the older PCIe 2.0 instead of the current 3.0. Some boards offer one or more legacy PCI slots, which are similar in length to PCIe X16 slots, but set closer to the rear edge, and won’t have retention clips at their forward edges.

MORE: Best Motherboards
MORE: All Motherboard Content

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22 comments
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  • jkhoward
    I find it extremely irritating that every time AMD has a new review, the next day you release more reviews than you have in the past month to push the AMD review off of your front page.

    It is things like this that make me not want to continue reading articles on your site.
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  • cats_Paw
    You forgot E-ATX Motherboards.
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  • bit_user
    I'm hoping mini-STX becomes a popular form-factor. It's what Intel uses for their NUCs and it's just the thing for micro servers.

    BTW, I think the difference between chipset-connected PCIe lanes and CPU-direct PCIe lanes should be highlighted, better. The latter is not supported for SLI and generally not a good idea for graphics cards (or even fast, PCIe-based SSDs, on DMI 2.0 chipsets).
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  • Shankovich
    Here's how Intel chooses them: Step 1: add USB 3.0 lane Step 2: Add one pin to socket Step 3: profit.
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  • redgarl
    One question, I have an MSI board and was thinking of getting an MSI GPU for OC Genie. Good or bad idea?
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  • Onus
    151198 said:
    You forgot E-ATX Motherboards.

    I made only a brief comment on it, since it adds no more expansion slots than is on ATX. The case selection will determine if a double-slot card can go in the bottom slot.
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  • Onus
    251426 said:
    One question, I have an MSI board and was thinking of getting an MSI GPU for OC Genie. Good or bad idea?

    OC Genie is a motherboard feature that is independent of the graphics card, so the GPU vendor won't matter. I've only used MSI's OC Genie on one board and not one I reviewed for TH. Like the other such automated tools I've tried, it may not do a great job, possibly setting excessive voltage and creating more heat than needed. Manual settings may give you better results, but obviously will take more time and effort.
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  • FritzEiv
    612443 said:
    I find it extremely irritating that every time AMD has a new review, the next day you release more reviews than you have in the past month to push the AMD review off of your front page. It is things like this that make me not want to continue reading articles on your site.


    I promise you it's not on purpose, it's just a coincidence. We try to publish our Best Picks updates monthly and we were running a little behind and . . . it's the end of the month. One of our editorial requests for our next site design is the ability to keep or place articles where we want, which would give us the ability to hold the AMD review in the #1 slot for a few days -- at the moment, it's just an artifact of the current design that the next feature bumps the previous one to the right.
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  • jkhoward
    "I promise you it's not on purpose, it's just a coincidence. We try to publish our Best Picks updates monthly and we were running a little behind and . . . it's the end of the month. One of our editorial requests for our next site design is the ability to keep or place articles where we want, which would give us the ability to hold the AMD review in the #1 slot for a few days -- at the moment, it's just an artifact of the current design that the next feature bumps the previous one to the right."

    Not sure why I cannot quote from the forums anymore, but thank you for sharing. Lately, it just seems like almost all AMD reviews or topics get pushed off the page the day after they're released which seems fishy to me. Glad to hear that isn't the case.
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  • Crashman
    151198 said:
    You forgot E-ATX Motherboards.
    No, because it's not really a thing for the consumer market. Over 90% of the boards you see listed at EATX aren't anywhere close to 13" deep.

    I guess we could have put it in the picture, but that would have just confused newbies even more: They would be looking for a case with 13" of clearance, based on the image, when the board they might be considering is only 10.7" wide.

    These are "extreme" enthusiast boards anyway, so just not talking about them in the article brings those few newbies with "extreme enthusiast" aspirations to the response thread, where we can have this conversation.
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  • eruditionfish
    Just wondering: are you not doing System Builder Marathons anymore? I haven't seen one for Q2 yet, and tomorrow's July...
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  • Crashman
    2258723 said:
    Just wondering: are you not doing System Builder Marathons anymore? I haven't seen one for Q2 yet, and tomorrow's July...
    Our agreement expired: It's in the air how we'll proceed from this point.
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  • ravewulf
    *Impatiently waits for AMD to launch socket AM4 based products*
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  • tsnor
    Enjoyed the article. How about the same for CPU selection ? It would complement the 'best CPU for $$' article nicely.

    Very much liked this articles Pros and Cons section. Especially in the AMD section where I know the least. Understand why it boring to repeat for socket 1151, but would have been nicer if you repeated.

    Not sure how to express Quality of MB vs 'buy the cheapest with the chipset you want". On my last two MB purchases (z97 and b85) I went with the cheapest I could find that had decent number of positive reviews. Not sure that was the right strategy, but no regrets so far.
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  • yocheco619
    Future Resistance isn't mentioned anywhere as a "Pro" when listing each type of mobo.

    That's understandable, but I was hoping for some kind of comment on a few of these that would suggest they are going to hang around for the next 2-3 years..

    None of these boards are future resistant for that duration?
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  • Onus
    While I probably could have included that on some of the latest boards, even the ones that aren't could still be suitable if used to build a PC that meets current and immediate future requirements.
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  • Crashman
    226731 said:
    Future Resistance isn't mentioned anywhere as a "Pro" when listing each type of mobo. That's understandable, but I was hoping for some kind of comment on a few of these that would suggest they are going to hang around for the next 2-3 years.. None of these boards are future resistant for that duration?
    It's become a myth. If you want future resistance you buy AMD, then in a few years the platform is still "current" only because they haven't developed a new high-end processor.
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  • yocheco619
    47340 said:
    While I probably could have included that on some of the latest boards, even the ones that aren't could still be suitable if used to build a PC that meets current and immediate future requirements.


    Thanks for the feedback!
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  • yocheco619
    8708 said:
    226731 said:
    Future Resistance isn't mentioned anywhere as a "Pro" when listing each type of mobo. That's understandable, but I was hoping for some kind of comment on a few of these that would suggest they are going to hang around for the next 2-3 years.. None of these boards are future resistant for that duration?
    It's become a myth. If you want future resistance you buy AMD, then in a few years the platform is still "current" only because they haven't developed a new high-end processor.


    Thanks for the feedback!
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  • jeffkiku
    Despite some of the other comments, I think this was an excellent article to introduce beginners to motherboards and all the variations associated with them. It would be great if you could provide this article in PDF form so it could be referenced later when this article is no longer available on the web!
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