Installing RAM is one of the easier steps in building a PC, but it’s also one where small mistakes cost you real performance. Get the slot order wrong and you lose 20%+ in bandwidth. Forget to enable the memory profile in UEFI and you’re running at 70% of the speed you paid for. Let’s do this right.

Before you install

Have these things on hand:

  • Your RAM sticks (still in the packaging is fine).
  • Your motherboard manual, opened to the RAM section.
  • The motherboard itself, with the RAM slots visible.

Check what you’re working with:

  • How many sticks did you buy? Most kits are 2 sticks.
  • What type are they? DDR4 or DDR5? Confirm this matches your motherboard.
  • What’s the rated speed?

Find the right slots

Modern ATX motherboards have four RAM slots. Mini-ITX boards have two. With two sticks, the slot you choose matters because of how dual-channel memory works.

The slots are numbered, typically A1, A2, B1, B2, working from the CPU outward. For a two-stick kit, the correct slots are almost always:

  • A2 and B2 (usually the second and fourth slots from the CPU).

This is sometimes also written as DIMM2 and DIMM4. Look at the motherboard’s silkscreen labels next to the slots, or check the manual to be sure.

Why these slots? They’re the ones routed for optimal signal integrity. Some boards work fine in any slots, but A2/B2 is the safe default for dual-channel operation.

Open the slot clips

Each RAM slot has retention clips at one or both ends. Push them outward until they click into the open position. On some boards only one side opens — the other end is fixed.

Orient the stick correctly

RAM is keyed so it only goes in one way. Look at the bottom of the stick: you’ll see a notch in the row of contacts, offset from center. The slot has a matching plastic tab. Line them up before you press down.

If you have the orientation wrong, the stick will physically not seat — don’t try to force it. Flip the stick around and try again.

Press down evenly

With the stick lined up:

  1. Hold the stick by its edges.
  2. Place it in the slot, oriented correctly.
  3. Press straight down with even pressure on both ends.

You’ll feel resistance, then a click as the retention clips snap closed automatically. Both clips should be fully upright and locked.

This step takes more force than feels comfortable for first-timers. The clips literally won’t close until the stick is fully seated. If only one clip clicks closed, push down on the side that didn’t seat.