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I'm looking to buy some new DDR3 ram for my computer and I have 4 slots on my motherboard with a maximum size of 32GB. In terms of speed, is it better to get 4 8GB ram modules or to get 4 2GB? Or a mix of both?

Edit: Going to be running Windows 8.1 x64 Pro

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closed as primarily opinion-based by Xavierjazz, Ramhound, Jens Erat, Moses, MariusMatutiae Jul 8 '14 at 14:46

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise.If this question can be reworded to fit the rules in the help center, please edit the question.

What operating system do you plan to run? Be as specific as possible. – David Schwartz Feb 22 '14 at 1:01
@DavidSchwartz sorry, updated. Please let me know if there are any other relevant specs – Richard Feb 22 '14 at 1:03
@DavidSchwartz updated – Richard Feb 22 '14 at 1:10
up vote 4 down vote accepted

Other things being equal, more memory is better than less. So 4 8GB modules is the best from a performance standpoint.

Having two modules is a bit faster than four. Two modules means one per channel while four modules means two per channel. With two modules on a channel, it takes a tiny bit of extra time to select the module. So unless you plan to really use more than 16GB, you could use 2 8GB modules.

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Oh I see, so you get the optimal speed when you only have 2 modules since it'll be 1 per channel. But then you want to maximize the performance of each module by getting the largest memory (which is 8GB). Thus 2 8GB modules is the best choice for a 4 memory slotted motherboard. Did I understand the line of thinking correctly? – Richard Feb 22 '14 at 1:20
@Richard Yes. But if you'll actually use more than 16GB, then the benefits of having more memory will outweigh the very slight performance benefit of having one module per channel. – David Schwartz Feb 22 '14 at 1:50

Memory modules of different sizes but otherwise identical specs should have the same speed.

The system is another story. Because of the above, there's no way that that 4 8 GiB modules could be slower than 4 2 GiB modules. If your computer will be faster with 32 GiB of RAM than it would be with 8 GiB depends on whether your system will be using more than 8 GiB, i.e. the applications you will be running.

Most current consumer-level CPUs have a dual-channel memory architecture, meaning that memory modules should always be installed in pairs (2 or 4). As @David Schwartz pointed out, 2 modules should be slightly faster than 4 (although I don't think there would be a noticable difference, but using only two modules also leaves room for future upgrades.

Keeping all of this this in mind, 2 4 GiB modules make sense than 4 2 GiB modules. In addition, they're probably cheaper. The same goes for 2 8 GiB modules vs 4 4GiB modules.

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