How to Overclock Your Computer’s RAM

Installing RAM in a computer.
Georgii Shipin/

RAM often comes from the factory with a lower speed than the silicon is capable of. With a few minutes in your BIOS and a bit of testing, you can get your memory to run faster than the manufacturer’s specifications.

What You Need to Know Before You Begin

RAM is quite a bit more complex than CPU or GPU overclocking, where you’re merely cranking a dial and praying your fancy all-in-one watercooler doesn’t turn your system into a space heater. With RAM, there are many knobs to turn, but it’s also much safer because they don’t produce much heat.

This does have real-world benefits. Every program you use stores its working data in RAM before loading it into the CPU’s internal cache, and programs that use a lot of it can churn through RAM like butter. In games, improvements in your RAM’s overall latency can cut down on frame times significantly. This can improve overall frame rates and (most importantly) reduce stuttering during CPU-intensive areas, where new data needs to be loaded from RAM into cache or VRAM.

RAM speed is usually measured in megahertz (Mhz). DDR4 stock speed is usually 2133 Mhz or 2400 Mhz, though the real speed is actually half of that since it’s Double Data Rate (DDR). On top of this, your memory has over twenty different timings which control latency, and how fast you can read and write. These are measured in terms of clock cycles and often grouped up under the “CAS Latency (CL)” abbreviation. For example, a midrange kit of DDR4 may be rated at 3200 Mhz CL16. Improving either the speed or timings improves latency and throughput.

The memory talks to the rest of the computer using a system called Serial Presence Detect. Through this, it gives the BIOS a set of frequencies and primary timings that it can operate at, called the JEDEC specification. This is the stock speed, and it’s baked into every DDR4 stick ever made.

JEDEC timings for RAM

But, Intel found a way to cheat the system. By offering another profile on top of JEDEC, called XMP (Extreme Memory Profile), they could run RAM higher than the standard speeds. If you buy RAM that’s rated over 2400 Mhz, you’re likely getting a kit with an XMP profile you can enable. This is sanctioned, factory overclocking.

Here’s the thing though—due to several factors, that overclock usually isn’t the best, and you can push it further than the manufacturer intended.

For one, manufacturers don’t bin everything to 100%. They’ve got to price the expensive kits higher, so it’s often the case that your memory came with the XMP profile it did because of product segmentation. Your kit also operates within a certain voltage level, usually 1.350 volts for midrange DDR4, but you can turn this up a bit yourself, something manufacturers do for higher speed kits.

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