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Memory And Expansion Card Slots

Best Of Tom’s Hardware: Beginner’s Guide To Motherboard Selection
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Memory type and configuration limits are normally thought to be tied to the memory controller, but a motherboard's slot configuration can further limit choices. For example, several microATX and smaller motherboards provide only two memory slots. Certainly, it's best to have at least four DIMM slots on a dual-channel motherboard or six on a triple-channel board, whenever the space for these modules exists.

All current motherboards support PCIe 2.0 graphics (5.0 GT/s), although a few older models that some vendors offer are limited to PCIe 1.1 (2.5 GT/s). There are few compatibility issues between PCIe 2.0 and 1.1 motherboards and graphics cards, although if different generations of parts are to be used, it is best to confirm compatibility by checking with our knowledgeable forum members.

While many non-graphics expansion cards, such as TV tuners and RAID controllers, now use the PCIe interface, several items have not yet been updated. Careful planning is required to make sure newer motherboards support all of your required legacy devices, while it's also a good idea to have at least one more PCIe slot than the original system plan requires.

PCIe x8 and x4 slots are suited for high-bandwidth devices, such as RAID controllers with eight or more ports and multi-connection gigabit network cards. Most consumer boards lack a physical x8 slot, although many have four or eight pathways in an x16 slot. Remember that any secondary x16 slot can also host x8, x4, and x1 cards if required.

PCIe slots with an open end at the front allow the use of longer cards in shorter slots, such as an x8 card in an x4 slot, as long as nothing else blocks the card from being inserted. Gigabyte’s GA-EX58-Extreme is a great example of a motherboard with an open-ended x4 slot that might have been able to support an x8 card, but instead has another obstruction (the white heat sink pin) that prevents anything longer than an x4 card from fitting.

Any of these slot types can prove equally valuable in a new build depending on your unique expansion card requirements.

Added-in Controllers

Adding to the vast array of features controlled by the southbridge are third-party devices, such as secondary network, SATA/eSATA, USB 3.0, and/or IEEE 1394/FireWire controllers. Several factors have pushed these out of the mainstream and into smaller high-end markets, such as improved SATA features, unavailability of USB 3.0 during chipset development, and decreased popularity of FireWire devices.

Add-in controllers usually employ PCI or PCIe x1 connections, using a logical "slot" where no room exists on the motherboard for a physical slot. With only seven physical slot positions available for a full-sized ATX build, a typical chipset supporting six PCIe x1 devices plus five PCI slots will have several unused connections, which can be routed directly to onboard  devices.

It may seem counterintuitive to disable any device that increases motherboard cost, but doing so can reduce boot time. For example, add-in SATA controllers have their own BIOS, but users with only a few drives will likely not have any of them connected to the add-in controller. Disabling the unused hardware will eliminate the time needed for its BIOS to run a drive check and get rid of the unnecessary "no drives found" message.

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Top Comments
  • 15 Hide
    quantumrand , February 11, 2010 5:31 AM
    Top choices for motherboards right now: Gigabyte, Asus, and MSI. Gigabyte is really the way to go, but there are a few Asus and MSI configs that you might prefer.
  • 14 Hide
    Crashman , February 11, 2010 7:01 AM
    one-shotWhat about EVGA?


    I'll let you in on a little secret: EVGA motherboards are a pain to overclock. Since that's EVGA's market, it's kind of a big deal. As an inexperienced manufacturer they're learning quickly, so hopefully we'll see the kinks worked out pretty soon.
Other Comments
  • -4 Hide
    shiroikaze , February 11, 2010 5:19 AM
    Seeing how I just built my first computer a couple days ago, this article came a little too late for me :p 

    Could've made my purchasing alot more quicker and painless.
  • 2 Hide
    micky_lund , February 11, 2010 5:30 AM
    ahh...the p55a-ud4p..great board
  • 15 Hide
    quantumrand , February 11, 2010 5:31 AM
    Top choices for motherboards right now: Gigabyte, Asus, and MSI. Gigabyte is really the way to go, but there are a few Asus and MSI configs that you might prefer.
  • 1 Hide
    one-shot , February 11, 2010 6:08 AM
    quantumrandTop choices for motherboards right now: Gigabyte, Asus, and MSI. Gigabyte is really the way to go, but there are a few Asus and MSI configs that you might prefer.


    What about EVGA?
  • 0 Hide
    tacoslave , February 11, 2010 6:11 AM
    quantumrandTop choices for motherboards right now: Gigabyte, Asus, and MSI. Gigabyte is really the way to go, but there are a few Asus and MSI configs that you might prefer.


    ah yes i got a got a msi 790fx gd70 with a combo from newegg (phenom II 955)and i absolutly love it. The best part is the overclocking utilities
    you can overclock fuckin everything in 5 min or less. Then i got another motherboard from zotac for 60 bucks (before rebate) and it died on me in less than a month and i'm still waiting on a rebate.
  • 14 Hide
    Crashman , February 11, 2010 7:01 AM
    one-shotWhat about EVGA?


    I'll let you in on a little secret: EVGA motherboards are a pain to overclock. Since that's EVGA's market, it's kind of a big deal. As an inexperienced manufacturer they're learning quickly, so hopefully we'll see the kinks worked out pretty soon.
  • 7 Hide
    porksmuggler , February 11, 2010 7:15 AM
    Great article for beginners. A quick browse through newegg, and I've built with every brand except EVGA, ZOTAC, and XFX (EVGA and XFX for graphics cards though). I've consistently gone with ASUS for my own and Gigabyte for customers when at all possible. I prefer ASUS for the best overall quality and Gigabyte usually provides the best value. I'm seeing a lot of comments for MSI lately, though I've never put them in the same league.
  • 2 Hide
    skora , February 11, 2010 7:32 AM
    This is a great reference article Crash. Lots of great info about chipsets, but I think the spot for socket type should be made long before choosing a mobo when spec'ing a rig. Is this part of Pauls "Balanced" articles?
  • 1 Hide
    Crashman , February 11, 2010 7:34 AM
    skoraThis is a great reference article Crash. Lots of great info about chipsets, but I think the spot for socket type should be made long before choosing a mobo when spec'ing a rig. Is this part of Pauls "Balanced" articles?


    http://www.tomshardware.com/reviews/beginners-guide-motherboard-selection,1289.html
  • 4 Hide
    nzprogamer , February 11, 2010 7:53 AM
    it takes long time to read all the information here but its all good to know for 1st time builder, love it. will there be some other advice like how to keep the case cool ( how to point the fans and where )?
  • 0 Hide
    skora , February 11, 2010 8:19 AM
    Quote:
    http://www.tomshardware.com/reviews/beginners-guide-motherboard-selection,1289.html

    I'd say you're article came first. Nice update!!!
  • 4 Hide
    Crashman , February 11, 2010 10:11 AM
    nzprogamerit takes long time to read all the information here but its all good to know for 1st time builder, love it. will there be some other advice like how to keep the case cool ( how to point the fans and where )?


    Eventually there will be an update to this article:

    http://www.tomshardware.com/reviews/build-part-1,1364.html
  • 0 Hide
    saran008 , February 11, 2010 10:21 AM
    Great guide for Beginners!
    Tom always rocks!
  • 0 Hide
    ytoledano , February 11, 2010 11:00 AM
    Given that the motherboard is one the least reliable components in any computer, the most important factor, IMO, is reliability.
  • 0 Hide
    saint19 , February 11, 2010 11:55 AM
    Very good article, currently I have a MSI K9A2 Platinum and works very good with my X4 955. I'm waiting for Fermi to change my mobo and RAM, and I would get an ASUS or Gigabyte...or maybe the 790FX-GD70.

    EVGA build excellent mobos, the problem is that only are for Intel processors and are very expensive ($499.99), with that price you can get the half of a good rig.
  • 0 Hide
    Anonymous , February 11, 2010 12:26 PM
    I had that Gigabyte X48T-DQ6... twice. Both had some kind of error that screwed up my internet connection, so I finally switched to an ASUS P5Q Deluxe. No more problems since.
  • 0 Hide
    Onus , February 11, 2010 12:46 PM
    I've had excellent results from ASRock, who seem to offer pretty high bang/buck. Even Foxconn is using more solid caps now, and doing so is probably what has allowed MSI to improve its quality image.
  • 0 Hide
    KupuAnd1 , February 11, 2010 12:52 PM
    I ones got a MSI board (like 5 years ago) and it was superb for reliability never dies and then I sold it. Now I got an EVGA and it is good.

    Waiting for USB 3.0 to go mainstream in boards to upgrade my mobo. I think right now is the best choice for future proof.
  • 0 Hide
    nevertell , February 11, 2010 1:09 PM
    Hey, that's my asus mobo. Although mine is underused, the other pci-e slot is empty because of the lack of money :( .
  • 1 Hide
    huron , February 11, 2010 1:22 PM
    Very nice article. It does include considerations when making a purchase and includes many details about components and all sorts of choices. Already forwarded it to a few people for reading - mostly people who want to know more, but no idea where to start.

    I hope you keep up this series - detailed articles to help beginners make decisions. This could be the starting point for many people

    Thanks again.
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