PC Cards and ExpressCards slide into a slot on the side of compatible laptops: They function similarly to expansion board slots. PC Cards have similar performance to PCI devices and ExpressCards perform about two and a half times as fast as PCI devices. A2A How can you fix a RAM slot on a PC motherboard that doesn’t recognize RAM sticks? Assuming the other slots recognize RAM ok, and assuming the RAM that you are trying to insert in the bad RAM slot works fine in other slots, then the problem is. Static RAM uses a completely different technology. In static RAM, a form of flip-flop holds each bit of memory (see How Boolean Logic Works for details on flip-flops). A flip-flop for a memory cell takes four or six transistors along with some wiring, but never has to be refreshed. First slot of second channel (B1) Second slot of first channel (A2) Second slot of second channel (B2) And so on. If you need to install multiply modules it is best to add them one by one. Installing memory is not hard, but my advice is to have motherboard manual open and ready. Those slots rarely come in any kind of sane order. The RAM slots are adjacent to the CPU socket. Look for the big heat sink at the top of the motherboard, and you'll see either two or four memory slots next to it.

If you’ve ever taken a look at a product page for sticks of RAM, or at the specifications for a CPU or motherboard, you’ve probably seen “memory channels” mentioned.

For many beginners, this sparks questions like, “What’s the deal? Does dual-channel mean I can only use two sticks? What do multiple channels do that one channel doesn’t? Can I use quad-channel RAM on a dual-channel motherboard?”

The answers to those questions and more can be found below, so read on!

RAM Channels: The What

Simply put, memory channels are the links between your RAM and your CPU through which data moves between the two. The RAM is the computer’s short-term memory, and the CPU is the main processor that does stuff with the information in the memory; the RAM channels are how that information moves back and forth.

To be clear, these memory channels are actual wires that exist on/in the motherboard. Though RAM kits may call their arrangements “channels,” the actual number of channels and the number of RAM sticks are independent of each other; any mention of channel count on a RAM kit’s product/specification page is just an informal, technically-incorrect way of referring to how many sticks of RAM there are in the kit. In addition, the number of RAM slots on a motherboard is independent of the number of memory channels. A channel needs only one stick to be used, and any more than that doesn’t necessarily stop things from working.

Most modern motherboards have two to four memory channels. On the AMD side, every AM4 socket motherboard has two memory channels, and every TR4 socket motherboard has four channels. On Intel’s side, every LGA 1151 motherboard has two memory channels, and every LGA 2066 motherboard has four memory channels. This means that, on our main chart, every configuration up to and including the “Enthusiast” tier has two memory channels. The “Extremist” and “Monstrous” tiers are the only rows which have four memory channels.

In addition, CPUs also support a certain maximum amount of memory channels. You don’t really need to worry about this, as every CPU will handle the amount of memory channels available on their supporting motherboards. There are only two notable exceptions: Intel’s i5-7640X and i7-7740X, which are both LGA 2066 CPUs, and very odd purchases anyway.

RAM Channels: The How

To explain what multiple channels do, let’s try an analogy.

Imagine a manufacturer of products:

Let’s say this manufacturer (your CPU), with potentially many factories (cores) in need of materials, makes orders for materials from only one supplier (memory channel). Even if the supplier has a whole lot of materials (capacity / stored data), and may run multiple warehouses (RAM sticks) of their own, it has a limited capacity for making shipments, and so can’t handle multiple shipments to the manufacturer at once. There may be multiple shipments ready to go, but they can’t actually start shipping until the current shipment is done.

A single-channel supplier warehouse attempting to serve a quad-factory manufacturer with one truck

The problem is, this manufacturer can often use materials faster than their supplier can ship them, and the delay from waiting on the supplier’s logistics system for consecutive orders can slow things down. Especially when this manufacturer’s factories are being heavily loaded with orders of their own from vendors and customers (your other components) while relying on materials orders, the supplier can pose a problem.

So, the manufacturer contracts with a second supplier in addition to the first. Now, the manufacturer does something efficient: They alternate orders between the two suppliers. This way, the manufacturer can have two simultaneous shipments coming their way, and they suddenly find that waiting on consecutive orders to be shipped is now significantly less of an issue, since their effective capacity for getting shipments has been doubled. This same idea can extend even further across more suppliers.

Really, how much the number of suppliers the manufacturer uses actually matters all depends on: how quickly materials are being used, how many factories they have (since each might come in need of materials at any given moment), how busy the manufacturer or specific factories are, and how quickly the suppliers themselves can send shipments to the manufacturer. Most of the time, this isn’t a big deal, but when things line up well or poorly, the number of suppliers (i.e. memory channels) can make a notable difference.

DDR5: Breaking the Status Quo?

If you’ve been keeping up-to-date on DDR5 memory, you may have seen mention of DDR5 RAM sticks (yes, each stick itself) having two memory channels. And what they’re saying is true, from a certain point-of-view. From my understanding, these “channels” aren’t like the memory channels described above, but still apply a similar (though not quite the same) concept on the stick-by-stick level.

Micron, one of the only three manufacturers of memory chips, describes this development as “essentially turning an 8-channel system as we know it today into a 16-channel system.” So what is going on here?

From what I can tell, it seems that each stick can work with two separate bunches of data, though it can’t be moving data from both bunches across the actual (physical, on-the-motherboard) channels at the same time. For example, a stick could be receiving data on one half, and be preparing to send data on the other half in the meantime. This is still a significant improvement in design over previous iterations of RAM like DDR4, though not quite as dramatic as it sounds at first. Reality is often disappointing; we’ll just have to wait and see if this turns out to actually be the case.

Conclusion

Let’s make one thing clear: to use multiple channels, you need multiple RAM sticks. Those RAM sticks should be installed so that you have at least one stick in each channel. The best thing you can do here is place your RAM sticks according to what your motherboard manual says. Though the slots are usually color-coded, this isn’t always the case, so check that motherboard manual.

For many country versions of our main chart, the linked 8GB options (and every 4GB option) are single sticks; so, without another stick of RAM, only one memory channel will be used. This is not the case everywhere, though, and all 8GB kits in the US version of the chart have two sticks for dual-channel. The 16GB options are dominated by two-stick 16GB kits, though some countries still have one-stick options linked. However, it’s up to you to choose how many sticks will work best for your system and your program tasks—there’s no need to get the exact kits we link.

If you are installing a RAM (memory) upgrade in your computer, or you are considering it, the following tips and information may help.

Memory buying tips

If you haven't purchased the memory yet, refer to our tips to finding the right RAM for your computer.

• Computer memory buying tips.

What Slot Does Ram Go Into One

Before getting started

If you've purchased the RAM and you're ready to install it, run down this checklist before beginning the installation.

1. Ensure you are familiar with ESD and its potential dangers.
2. When installing the memory, make sure the computer is off and unplugged.

Locate memory slots and install memory

Follow these steps to safely install RAM modules in your computer's motherboard.

DIMM (DRAM, SDRAM, and DDR) memory installation steps

When handling memory, hold it by the sides at each end of the module. Be careful not to bend, flex, or drop the memory while handling it. When pushing the memory into the computer, do not apply an excessive amount of pressure. Doing so could cause damage to the memory module, and the slots on the motherboard. Finally, when installing the memory, distribute the pressure evenly by pressing on both corners of the memory module.

Once the memory is purchased, locate the memory slots on the computer motherboard. If no memory slots are available on the computer, one or more memory modules must be removed before the memory can be installed.

If the computer has a small form factor, it may be difficult to access the memory slots. You may have to temporarily remove cables or expansion cards before you can access them easily. When disconnecting anything from the computer, make sure you can remember where each cable and card goes.

Each slot on a motherboard that supports a DIMM is a bank; therefore the computer works if one memory module is purchased.

Examine the memory module before installing it into the computer. At the bottom of the memory module, you should notice one or more notches at the bottom of the card. These notches look like those shown in the picture below.

Make sure that the notches match up with the memory slot you are installing the memory into. These notches allow the memory to be installed only in one direction. If the memory is incompatible, it will not physically match with the slot.

After verifying the notches and direction, the memory needs to be installed, move each memory slot tab out or away from the memory module. These tabs will snap into place as the memory module is installed.

Once these tabs are moved out, gently and firmly push the memory module into the slot. As the memory module is being pushed, the two tabs should snap and hold the memory module into place.

After the memory is installed in the computer, plug the computer back in, and turn it back on. As the computer is booting, the memory should be automatically detected and set up. If you have any difficulties with the memory detected or set up, enter the BIOS setup, and verify the memory is correctly detected by the system.

RIMM memory installation steps

What makes RIMM memory modules different from DIMM memory modules is the C-RIMM memory module. This module allows the computer to have a continuous flow of data. When installing a new RIMM, remove the C-RIMM. This module is a small circuit board and has only a few or no chips on it.

When the C-RIMM module is removed, and the two tabs are in the outward position, push the RIMM memory module to a vertical or 90-degree angle. As the memory module is being pushed, the two tabs should snap and hold the memory module into place.

Notebook (laptop) memory installation steps

Before the memory can be installed into a notebook, the memory slots must be located. If you are unfamiliar with where these slots are located, below is a listing of possible locations:

1. On a compartment on the bottom of the laptop.
2. Under the keyboard.
3. In the computer.

If you cannot locate the slots after looking at each of the above recommendations, we recommend you contact the computer manufacturer for additional help and information.

Once the slots are located, the next step is to install the computer memory. Today, most laptops follow the same memory installation.

Because laptops are thin compared to a desktop computer, the memory banks are horizontal with the laptop. The memory must be inserted at an angle (approximately 75 degrees). Once it's in the slot, press down on the memory to snap it into place. The memory should also lay horizontally with the computer.

SIMM memory installation steps

30 and 72-pin SIMM memory modules must occupy a bank. Computers that use 72-pin SIMMs have two sockets as one bank. Therefore, two memory modules of equal value must be installed in pairs, unless instructed otherwise by the computer or motherboard manufacturer.

The installation of most SIMM memory is the same. The memory is placed into the slot at a 75-degree angle and while still in the memory slot, moved to a vertical (90-degree) angle. As the memory module is moved to a vertical position, it should snap into place. When installed, ensure that both sides of the memory module are snapped into place. If a memory module is not installed properly, it could cause damage to the computer.

We recommend the larger memory modules be installed in the lowest available banks. For example, if the computer has two 4 MB memory modules and you're installing two 32 MB memory modules, place the 32 MB memory modules either in banks 0 and 1, or 1 and 2.

Some computer manufacturers may require SIMM modules be installed in a certain order. So, if your new computer memory installation does not work, consider switching the location of the memory.

Set memory in BIOS

What Slot Does Ram Go Into Another

Once the memory appears is installed into the computer, test it. Put the case back on the computer. Connect the keyboard, monitor, and power to the computer. Turn on the computer.

We recommend you do not connect the rest of the cables yet. If you experience problems, you may have to disconnect all the cables again.

As the computer is booting, enter the BIOS setup, verify that the memory is detected, and if necessary, adjust the settings to match your memory specifications. When verification and configuration is complete, save the settings, exit BIOS, and reboot the computer.

Troubleshooting

If you encounter any problems when installing the RAM, refer to our Computer memory help and support.

Additional information

• See our memory definition for further information and related links.