How To Build A PC

Step 5: Select Memory

When it comes to picking memory for your build, there are numerous options. If you find the whole process overwhelming, the easiest answer is to simply buy 1.5-volt DDR3-1600 modules with CAS 9 timings or 1.2-volt DDR4-2133 modules with CAS 15 timings, depending on your platform. The DDR3 sticks are universally supported on many motherboards and the DDR4 sticks are universally supported on Intel’s X99 and Skylake platforms. Even better, both are inexpensive and readily available as both 4 and 8GB sticks. If that solution is a bit too simple for you then checkout our Best Memory column, which provides recommendations for both DDR3 and DDR4 kits.

There are noticeable performance benefits for similarly-priced DDR3-1866 (PC3-14900), particularly if you're using a CPU's on-die graphics engine for gaming, and this speed functions normally, even with processors that are not officially designated to use it (primarily older models or low-energy platforms). Furthermore, the same easy benefits of DDR3-1866 are even available with most DDR3-2133 kits and modern performance-oriented processors.

However, the problem with recommending faster memory kits is that they often require at least some manual configuration. If you're not comfortable tooling around in your motherboard's firmware, they might actually drop you to lower performance levels.

You see, Intel’s XMP (eXtreme Memory Profiles) technology facilitates extended memory settings beyond the basic automatic-configuration technology called SPD. Although XMP originally allowed motherboards to set overclocked options like nonstandard voltages and data rates, most of today's XMP-capable modules operate at standard voltage levels and frequencies. Still, when you first boot up, they typically default to either DDR3-1333 or -1066. Going higher requires that you manually enable an XMP profile. Even some DDR3-1600 modules employ XMP (rather than SPD values) to achieve their rated performance levels, and this is particularly true of reduced-latency (CAS 7, CAS 8) modules.

Memory faster than DDR3-2133 is usually expensive and not really required. Our tests have shown that DDR3-2400 is barely beneficial, and only in situations where you're leaning on integrated graphics. We've even seen data rates above 2400 MT/s hurt performance as the motherboard attempts to increase stability.

Those who like taking advantage of the latest technologies will be thrilled to hear that Intel’s latest generation Skylake CPUs officially support DDR4 memory. Better yet, the price of DDR4 has fallen to the point where it’s not really that much more expensive than a similar sized and performing DDR3 kit. Unfortunately, those loyal to AMD are either going to have to migrate to an Intel system or wait for AMD’s next generation of CPUs before they can make use of DDR4.

In terms of memory quantity, we recommend no less than 4 GB even for the cheapest of systems, though 8 GB will yield a noticeable performance boost. For those who plan on gaming, we recommend at least 8 GB of RAM if you’re on a budget, with 16 GB recommended for those who can spare the increased cost. Finally, if you plan on doing any sort of photo/video editing or heavy multitasking, we recommend you start at 16 GB and add more if you find that you need it.

Our memory reviews show a wide range of options, and buying name-brand modules with lifetime warranties from reputable vendors is good insurance against unexplained system instability.

MORE: Best Memory
MORE: All Memory Articles

MORE: Memory in the Forums

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32 comments
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  • "the power supply is actually one of the more important parts of a build"
    Thank you!!

    Or rather, let's do what the cool kids are doing and rather post a GIF:
    https://giphy.com/gifs/the-office-thank-you-michael-scott-1Z02vuppxP1Pa
    3
  • Great piece for a lot of first-time builders. This should have a sticky somewhere on the site so it doesn't get buried :-)
    5
  • Quote:
    "the power supply is actually one of the more important parts of a build" Thank you!! Or rather, let's do what the cool kids are doing and rather post a GIF: https://giphy.com/gifs/the-office-thank-you-michael-scott-1Z02vuppxP1Pa


    Seriously, not enough people realize how import a good PSU is. I am working with someone is heavily overclocking an i7 and two 970 in SLI as well as 4 SSD and a few hard drives, a bunch of fans, with a 750W PSU.
    -2
  • Also... I am digging the age of some of these images.
    4
  • Quote:
    Quote:
    "the power supply is actually one of the more important parts of a build" Thank you!! Or rather, let's do what the cool kids are doing and rather post a GIF: https://giphy.com/gifs/the-office-thank-you-michael-scott-1Z02vuppxP1Pa
    Seriously, not enough people realize how import a good PSU is. I am working with someone is heavily overclocking an i7 and two 970 in SLI as well as 4 SSD and a few hard drives, a bunch of fans, with a 750W PSU.


    unless i'm thinking wrong, isn't that within the power limits of a 750? im even assuming that each gpu is 300 watts and i know they shouldn't hit that even with the most aggressive of ocs

    granted there is a distinction between a good psu and a bad one, but im just assuming its a good one.
    3
  • Motherboard slots haven't evolved much. Wished every slot was like a USB slot
    0
  • 612443 said:
    Seriously, not enough people realize how import a good PSU is. I am working with someone is heavily overclocking an i7 and two 970 in SLI as well as 4 SSD and a few hard drives, a bunch of fans, with a 750W PSU.


    Your point being... ?
    3
  • Steps 1 and 3 should be combined, and step 2 comes after 1 and 3. You better worry about the CPU and motherboard combo compatibility before you worry about a graphics card.
    -1
  • Sorry, meant steps 2 and 4 before 3.
    0
  • I love when you see a $1500.00 build with top quality components and then they have a $40.00 PSU listed with it.
    5
  • IMO the very first component selection for a gaming build should always be the .... MONITOR.
    Decisions on where and how to spend the rest of the budget can only be made once you know the resolution , and whether its 60 Hz, 144 Hz or whatever else is available
    1
  • Gonna throw in my disagreement on the priority, mentioned nice and early in the article. The first thing you pick is never your case. There's 3 things you can decide to be your starting point when building a pc to make it a smooth ride; either, 1. Budget. 2. CPU 3. Graphics. By picking 1 of these 3 things as your starting point, you can have a very smooth build process. Does that mean you buy your case last? No, I've seen plenty of builds where the case arrives first as a way of storing the items, but when you want a solid build, your case is last priority, as it has no impact on your performance and restricts the size of your items.

    Even if you wanted to build an odd form factor, like an itx, you would still pick the cpu or the budget before the case.
    2
  • Thank you for explaining ESD correctly. I have been annoyed with articles over exaggerating about ESD a lot. So just touching something metal can help? Well, next time I think I'll set a PC on my wooden desk instead of the carpet.
    0
  • Quote:
    I love when you see a $1500.00 build with top quality components and then they have a $40.00 PSU listed with it.


    The XFX TS Bronze 550 comes down to $43 ish from time to time and that's a mighty fine PSU to power a single graphics card build.
    0
  • Quote:
    "the power supply is actually one of the more important parts of a build" Thank you!!

    While not unimportant, it gets far too much attention on the forum's here. PSU's are only relatively rarely the cause of issues, and I'll go out on a limb and say that virtually ANY modern 650W PSU (even ultra-cheap China garbage) will reliably power a single GPU and CPU, regardless of model or how much OCing you do to them.
    -3
  • 269694 said:
    Quote:
    I am working with someone is heavily overclocking an i7 and two 970 in SLI as well as 4 SSD and a few hard drives, a bunch of fans, with a 750W PSU.
    unless i'm thinking wrong, isn't that within the power limits of a 750? im even assuming that each gpu is 300 watts and i know they shouldn't hit that even with the most aggressive of ocs granted there is a distinction between a good psu and a bad one, but im just assuming its a good one.
    You're exactly right. We've been using high-quality power supplies in most of our System Builder Marathon machines, and dual 970s was in one of the builds. The super-high recommendations you see from other sites are a response to most builders using mediocre-quality units.
    1
  • 416912 said:
    Gonna throw in my disagreement on the priority, mentioned nice and early in the article. The first thing you pick is never your case. There's 3 things you can decide to be your starting point when building a pc to make it a smooth ride; either, 1. Budget. 2. CPU 3. Graphics. By picking 1 of these 3 things as your starting point, you can have a very smooth build process. Does that mean you buy your case last? No, I've seen plenty of builds where the case arrives first as a way of storing the items, but when you want a solid build, your case is last priority, as it has no impact on your performance and restricts the size of your items. Even if you wanted to build an odd form factor, like an itx, you would still pick the cpu or the budget before the case.
    Exactly wrong. The first thing people do is say "I want a LAN box" or "I want a media player" or "I want a big gorgeous office PC". They're picking a case SIZE when they make those FIRST statements, so size comes first in the discussion.
    1
  • Quote:
    416912 said:
    Gonna throw in my disagreement on the priority, mentioned nice and early in the article. The first thing you pick is never your case. There's 3 things you can decide to be your starting point when building a pc to make it a smooth ride; either, 1. Budget. 2. CPU 3. Graphics. By picking 1 of these 3 things as your starting point, you can have a very smooth build process. Does that mean you buy your case last? No, I've seen plenty of builds where the case arrives first as a way of storing the items, but when you want a solid build, your case is last priority, as it has no impact on your performance and restricts the size of your items. Even if you wanted to build an odd form factor, like an itx, you would still pick the cpu or the budget before the case.
    Exactly wrong. The first thing people do is say "I want a LAN box" or "I want a media player" or "I want a big gorgeous office PC". They're picking a case SIZE when they make those FIRST statements, so size comes first in the discussion.


    I have to agree with you on this Crashman. Whenever I go to build a new system for friends or relatives I always ask what they're going for in terms of use. I like to go with the Form follows function principle which is that the shape of a building or object should be primarily based upon its intended function or purpose.
    0