[Guide] RAM Buyer's Guide

[You_are_a_cunt]

Ram is ram. Just pick one that goes with your color scheme.

 

If you’ve seen this reply, you’re probably wondering what RAM to buy. I’ve given this answer as have many other people have (both on this forum and mostly everywhere else). Does this really turn out to be entirely true? For the most part, yes. HOWEVER, there are a few cases where this isn’t entirely true and our answer should vary from case to case.

 

RAM speeds. What are they exactly?

 

RAM Speed is the maximum number of clock cycles per second that the RAM operates on. Since we’re using Double Data Rate RAM (DDR RAM for short), our memory will communicate twice every cycle. You’ve probably noticed that your Task Manager shows your RAM speed to be halved (800 MHz for 1600 MHz RAM and so on).

 

To put it in simpler terms, RAM Speed dictates how much bandwidth is available for data transfer.

 

We often see RAM being labeled as PC3-10600, but what does THAT mean?

It’s just a fancy way of saying that your DDR3 (PC3) memory has a bandwidth of 10600 MB/s.

How do you get this number? That’s actually fairly easy, assuming you know your RAM’s rated frequency. In this case, I used 1333 MHz.

 

666.5 MHz (1) clock rate * 2 (2) * 8 bytes (3)= 10,664 MB/s (4)

 

Now to break down the formula:

 

1. Hey, you said you used 1333 MHz for the example! What gives?!

Remember when I said that your Task Manager will show your ram speed halved? There’s your answer.

2. Why did you multiply by 2?

We are using Double Data Rate RAM and, as previously mentioned, the ram communicated twice per cycle. If we were using Single Data Rate (or SDR), we would have multiplied by 1, since it only communicates once per cycle.

(3) Why 8 bytes? This is actually a shortcut. The result is obtained from dividing the number of bits transferred (64) by the number of bits per byte (8), giving us the magic value of 8 bytes.

(4) I thought you said that the 1333MHz PC3-10600 had a bandwidth of 10600 MB/s! Well, this is sort of true. Our formula spat out 10,664 MB/s. Using industry standard, this value is rounded up to 10,600 MB/s. You will see similar approximations when calculating the peak transfer rate of 1866MHz (PC3-14900) and 2133MHz (PC3-17000) (I’ll be ignoring the 800 and 1066MHz modules, since nobody should be using those).

 

The most frequent DDR3 sticks that people buy are 1600 and 1866MHz, since they are, for the most part, the cheapest and the most generally available. This doesn’t mean you should only buy those, but you need to take into account the maximum frequency that your CPU and motherboard can take with and without overclocking your memory (there’s also the case of maximum memory they can use, but that’s for another part of this sort-of-guide).

 

Linus made a video about RAM speed and timings!

 

What kind of memory can I use?

 

This depends on your CPU and your motherboard.

All CPU and motherboard manufacturers will state the maximum amount of RAM their products can use. For CPUs it’s generally high enough that you don’t have to bother checking (however, if you are building retro-PCs, you should check). For motherboards the maximum memory ranges from 8GB (usually when dealing with laptops) to 128GB (workstation motherboards) (DDR4 motherboards break the 128GB limit that is set by the maximum amount of memory per stick of DDR3).

Maximum memory is mainly influenced by motherboard size (subsequently by number of memory slots on the motherboard). ITX motherboards often have a 16GB maximum (due to their 2 memory slots); mATX, ATX usually go up to 32GB (4 memory slots). Enthusiast platforms as well as workstation grade ones that can go up to 128GB (having 8 memory slots).

 

When does memory speed actually matter?

 

If you’re on a tight budget and find yourself having to use an iGPU (integrated GPU) like Intel’s HD Graphics series, Intel Iris or one of AMD’s APUs, then you’ll want to max out on the memory speed.

For the most part I recommend buying AT LEAST 1600MHz memory or 1866MHz, as you won’t be seeing much benefit from higher speeds past 1866MHz.

 

ECC versus non-ECC?
 

Unless you’re building a server, you’ll want non-ECC.

ECC stands for Error-correcting code that detects and corrects most common kinds of internal data corruption. Unless the manufacturer specifies that the motherboard supports ECC memory, odds are it doesn’t, so you’ll want to stay away from those.

 

Memory latency! Lower is better!

 

CAS latency, or CL, is the delay time between the moment a memory controller tells the memory module to access a particular memory column on a RAM module, and the moment the data from the given array location is available on the module’s output pins. Or so Wikipedia says.

The not so scientific explanation:

CL is like your internet ping. The lower it is, the faster data gets to you.

This is the hardest part to explain from an electrical standpoint, so I won’t even try.

The most frequent CL ratings you’ll find are CL11 and CL9 (or at least these are the most common I’ve noticed).

From general observation, if the memory speed is higher, the latency is higher, with DDR3-3300 going all the way up to CL16.

Bottom of the line when it comes to CL: lower is better, but not that much better. You’ll be fine with CL11 if you can’t get CL9. The performance benefit will only pop up in synthetic benchmarks or applications that are highly dependant on memory.

 

XMP vs. non-XMP?

 

XMP or Intel Extreme Memory Profile is an optimization brought to memory latency, therefore you should try to get XMP-enabled memory when possible (assuming your motherboard supports XMP, that is) and turn it on.

 

Now to the part everyone hates.

 

How much memory do I need?

 

The answer is, sadly, it depends. Yes, I know. Linus already covered it in a AFAP (he probably covered all of this post, but heck, I’m bored and I wanted to write this for a while now).

Gone are the days when 4GB of RAM was enough even for the most demanding games. T’is no more the time when even 8GB of RAM was more than enough.

With most games these days asking for a minimum of 8GB of RAM, it’s time we start recommending more.

I’m using 8GB of RAM right now and I’m still doing fine (except when drivers decide to crap themselves and leak memory like ice-cold water leaked into the Titanic), but it won’t be too long until I will find myself ordering a couple extra sticks of RAM.

16GB now seems to be the sweet spot for memory, although nobody’s going to yell at you if you go up to 32GB.

tl;dr: 8 is fine, 16 is better, 32 might still be too much.

 

So, I’m getting 16 gigs of RAM. 2x8 or 4x4?

 

Always 2x8, and that’s for a couple of reasons:

#1: More room for future expansion. If your 16 gigs turn out not to be enough, you’ll have room to buy another two 8 gig sticks further down the line. If you go the 4x4 way, you’ll find yourself either shelving the 4 sticks you have in order to upgrade or just end up selling them. In the long run, you’ll be spending more money on ram.

#2: Latency. sort of. If you’re using 4 sticks of memory, you’ll have a CL on each of them. Same goes for 2 sticks. But overall you’ll benefit more from only having two latency points rather than four.

 

Now to the visual part of buying RAM.

 

Heatsink vs no heatsink?

 

RAM sticks without heatsinks are so damned ugly. Unless you need very low profile memory, I’ll always be recommending sticks that have heatspreaders on them.

 

Does the color mean something?

 

No. You’ll generally find the same memory in 2-3-4-5 color variations and sometimes you’ll even find them with differently designed heatsinks. Just go with whichever color matches your build. Hell, there’s some LED memory sticks out there as well (looks like it’s what all the kids are doing these days).

 

Manufacturer?

 

I’m pretty comfortable recommending Kingston HyperX and Corsair but I’ve seen many people recommend Crucial, G.Skill, Mushkin and Samsung. As with all purchases, taking a look at customer reviews will never hurt.

 

Conclusion?

If you’re on a budget, you’ll be looking at something around the lines of 8GB of (at least) 1600MHz DDR3.

If your budget is slightly higher (~$1k), you’ll be looking at about 16GB of (again, at least) 1600 DDR3 or 2400MHz DDR4

If your budget is over the top, you’ll be looking at 16GB or more 2400 or 2666MHz DDR4 (although I suspect that with a high budget the general aim would be around 32GB of 2666 or 3200MHz DDR4).

 

If I’ve made any errors, please point them out and I’ll gladly edit.

[minibois]

Should I do a guide on how to not annoy people who use Dark Theme?

/jk, there's a user script I can install to avoid this.. But anyways, press edit > ctrl + a > press the remove format button.

Nice guide by the way. Some useful information

[You_are_a_cunt]

Should I do a guide on how to not annoy people who use Dark Theme?

 

 

/jk, there's a user script I can install to avoid this.. But anyways, press edit > ctrl + a > press the remove format button.

Nice guide by the way. Some useful information

ARGH!

I copy-pasta'd it from Google Docs. Gimme a sec and imma f33x it.

 

There. Done. Set font color to automatic.

Hope it fixed it

[LavaCooled]

This is a really good tutorial. I'm definitely keeping this page bookmarked. Keep up the good work!

[You_are_a_cunt]

This is a really good tutorial. I'm definitely keeping this page bookmarked. Keep up the good work!

Thanks Also taking requests, since I'll be getting bored during my time off work

[MageTank]

Thanks Also taking requests, since I'll be getting bored during my time off work

I have a couple of issues with this guide. First of all, you completely neglected channels (single vs dual vs triple vs quad). You also left out rank interleave (Which should have been mentioned in your 2x8 vs 4x4 section). 

 

In dual channel, DDR3 1333mhz (PC3 10600) has a peak theoretical memory bandwidth of 21.2GB/s (10,600 x 2). In quad channel, it would be a peak theoretical bandwidth of 42.4GB/s (10,600 x 4). 

 

While this might just be a buyers guide, and channel information can be best left to say, a motherboard guide, i still believe it is useful information to pass on to consumers, so they know the difference between buying memory kits rated for specific channels, and kits that are not rated for specific channels. Aside from those two pieces of information, the guide is helpful. Great job.

[You_are_a_cunt]

I have a couple of issues with this guide. First of all, you completely neglected channels (single vs dual vs triple vs quad). You also left out rank interleave (Which should have been mentioned in your 2x8 vs 4x4 section). 

 

In dual channel, DDR3 1333mhz (PC3 10600) has a peak theoretical memory bandwidth of 21.2GB/s (10,600 x 2). In quad channel, it would be a peak theoretical bandwidth of 42.4GB/s (10,600 x 4). 

 

While this might just be a buyers guide, and channel information can be best left to say, a motherboard guide, i still believe it is useful information to pass on to consumers, so they know the difference between buying memory kits rated for specific channels, and kits that are not rated for specific channels. Aside from those two pieces of information, the guide is helpful. Great job.

Ah crap yer right. I'll add info on channels and ranks later today when I'll be taking a break at work

[Tsuki]

great guide!  my only issue, the Titanic didnt leak water, it took on water. just sayin..

[You_are_a_cunt]

great guide!  my only issue, the Titanic didnt leak water, it took on water. just sayin..

I admit making no such mistake. Also, a leak is a leak. Now here's a leek

[You_are_a_cunt]

Slight update!

 

Added link to the FAP video on RAM Speed and Timings!

[FRN]

Well said. Thanks OP.

[Moonzy]

On 11/30/2015 at 7:40 PM, revsilverspine said:

Always 2x8, and that’s for a couple of reasons:

b-b-but... what about quad channel rams supporting cpu? D: like the 5820k

 

On 11/30/2015 at 7:40 PM, revsilverspine said:

Hell, there’s some LED memory sticks out there as well (looks like it’s what all the kids are doing these days).

LED? pfft... we have plasma tubes now bruh

Spoiler

 

 

[Unhelpful]

On 4/22/2016 at 1:14 AM, Moonzy said:

b-b-but... what about quad channel rams supporting cpu? D: like the 5820k

It ends up meaning very little performance-wise, except for in synthetics.