It wasn’t long ago that 8 GB of RAM was considered over-the-top for a PC.
Now it seems like you can’t run much on a PC with that much RAM.
If you want to play a game, you need to kill all the background processes before you can play relatively lag-free.
Therefore, you decide it’s time to add another 8 GB stick to your motherboard.
With all those dizzying specifications, though, you’re wondering whether you can simply buy a DDR3 stick and install it.
Will Any DDR3 RAM Work On My PC?
You can use any DDR3 RAM on your PC as long as you have room for extra sticks on your motherboard and you don’t exceed the motherboard’s RAM cap.
The optimal setup is to add an identical stick to what you already have.
If you’re having trouble finding one, you can buy a similar stick.
Note that if you already have two sticks on your motherboard (e.g., two 4 GB sticks instead of an 8 GB), it’s best to add two sticks of the same kind.
However, if your motherboard only has two slots, you should replace both sticks with identical sticks of higher capacity.
This way, you’ll get the highest performance boost.
How To Determine Motherboard And RAM Compatibility
The first step to upgrading your RAM is checking which technology your motherboard supports.
Home systems usually run on Double Data Rate Synchronous Dynamic Random Access Memory (DDR SDRAM), which has been around for over twenty years.
Since then, the technology has undergone five iterations, making it faster and increasing its frequency.
Here’s an overview of the five DDR generations and their respective speeds.
|Generation||Year Released||Maximum Bus Clock Rate|
As you can see, each generation has become faster than its predecessor.
However, the increases in clock rate are incremental as there are a few standards for each generation.
For example, DDR3 RAMs come in the following standards:
Note: The standard clock frequencies are double the bus clock rate because DDR technology allows data transmission on both edges of the signal, meaning it can transfer two bits with one signal, hence the Dual in DDR.
DDR versions aren’t forward or backward-compatible, meaning you can’t install a DDR2 or DDR4 stick on a motherboard that supports DDR3—it’s physically impossible.
However, as long as you buy the right generation of RAM, you don’t have to worry about the standard or frequency.
How To Check Supported DDR Version
It’s easy to check which DDR version your motherboard accepts.
First, you have to identify your motherboard’s manufacturer and model.
Here are two ways:
1. Command Prompt
If you’re comfortable with the dark window and typing commands, you can use the Windows Instrumentation Management utility from the command line.
The utility lets you diagnose errors and view log information from various Windows and hardware components.
To find your motherboard model using the command prompt, follow these steps:
- Press the Start key, type in cmd, and hit Enter.
- Once the command prompt opens, type in wmic baseboard get product,Manufacturer.
- You’ll see the manufacturer and model as soon as you press Enter.
2. System Information UI
If you prefer straightforward clickable UIs, you can use the System Information tool in your Windows.
- Open the Start Menu and type in System Information.
- Once the window opens, click on System Summary.
- Scroll down to find your BaseBoard Manufacturer and BaseBoard Product.
With that information at your disposal, search the model and visit the manufacturer’s website to find the specs.
Note that your motherboard has to support DDR3 specifically as different DDR versions aren’t compatible.
CPU And RAM Compatibility
When choosing RAM, the motherboard isn’t the only component that needs to be compatible.
You should also consider which DDR version your CPU is designed to work with.
However, that point is often overlooked because motherboard-CPU compatibility takes priority.
Essentially, if you buy a RAM stick that works with your motherboard, you won’t run into any problems because the CPU also has to be compatible with the motherboard.
To see which DDR version your CPU expects, open the System Information tool as explained above.
Under Processor, check the model and manufacturer.
Then, Google that information to find the CPU’s detailed specs.
How Much RAM Does My Motherboard Support?
Once you’ve identified the DDR generation supported by your motherboard, it’s time to see if your computer can handle more RAM than already installed.
Two factors determine the maximum supported RAM:
- Your operating system
- Your motherboard’s max capacity
Let’s consider each one in more detail.
1. Operating System Maximum RAM
Some users are surprised to find out that operating systems can only handle a limited amount of RAM.
The limitation is in the addressing mechanism used to identify individual blocks of RAM.
Older operating systems use a 32-bit scheme.
Therefore, they can support up to 2^32 bytes of RAM, roughly equivalent to 4 GB.
Newer versions have moved to a 64-bit design, which affords 2^64 bytes.
Theoretically, that number translates to about 16 exabytes or one million terabytes!
In real life, though, most operating systems can’t go beyond two terabytes, which is still an insane amount for any home user.
How can you tell if your Windows is 32 or 64-bit?
Right-click on This PC and select Properties.
Then, in the window that opens, look for System Type.
2. Maximum Motherboard Capacity
If you have a 64-bit OS, you’ll most likely have some room to upgrade your RAM.
Most modern motherboards are designed to handle 64 or 128 GB of RAM.
However, to be sure, find the motherboard’s model as explained above.
Then check the tech specs on the manufacturer’s website to see the max supported RAM.
3. Available DIMM Slots
Other than capacity, your motherboard has to have room for extra RAM sticks.
RAM sticks are mounted on a Dual Inline Memory Module (DIMM) slot.
You probably already have two full slots on your motherboard.
If you have a quad-channel motherboard (more on this later), you’ll likely have two other open slots to add extra RAM.
If all the slots are occupied, you should consider replacing two sticks with higher-capacity ones.
It’s possible to upgrade a single stick, but a dual-stick setup is usually slightly faster.
We’ll explain why later in the article.
Note: Laptop RAMs don’t fit into DIMM slots. They’re slightly smaller and require a Small Outline Dual Inline Memory Module (SO DIMM) socket. Remember that you need a different module type if you’re considering upgrading your laptop.
What Other Specs Should You Consider Before Buying RAM?
Choosing a compatible RAM can be confusing because there are a few specs to consider.
However, if you pay attention to everything we’ve said so far, you’re unlikely to run into large problems.
With that reassurance, let’s go over the small details you need to consider to optimize the performance boost you’ll get from the new RAM.
Typical DDR3 RAM sticks range in capacity from 4 to 16 GB.
Older generations came in 1 or 2 GB packages, but RAM has become more affordable as technology has advanced.
Most buyers face a common dilemma: choosing between a high-capacity module or two modules with half the capacity.
The second approach tends to offer more advantages, including:
- More bandwidth. Two sticks can send and receive information in parallel.
- More affordable. Usually, buying two lower-capacity sticks costs less than buying one with double capacity because larger sticks are harder to manufacture.
- More reliability. When you have two sticks, even if one of them fails, you’ll still be able to use your computer until you buy a replacement. However, your computer won’t turn on if you only have one stick that’s gone bad.
The only disadvantage of installing two RAM modules is that your actual available memory will be slightly less than the nominal value.
The BIOS and operating system reserve part of the available RAM for system-level operations.
For example, you can only use 3.5 GB of a 4 GB module to run your applications and games.
Now, if you have two 4 GB modules, your total available RAM will be around 7 GB, whereas if you have a single 8 GB module, you’ll have access to around 7.2 GB.
As you can see, the difference isn’t significant enough to outweigh the benefits of installing two smaller modules.
RAM frequency is often mistaken for speed, but speed is a function of frequency, bandwidth, and latency.
We’re better off considering frequency on its own.
Frequency refers to the number of signals your RAM can process in a second.
Since DDR RAMs transmit two bits with each signal, the bus clock rate will be half the frequency of your RAM.
In general, higher frequency means faster operation.
However, unlike CPUs, the higher frequency doesn’t impact speed much because RAMs operate differently from CPUs—they simply store information without processing it.
The actual performance gain is marginal because multiple other factors affect the final results.
These include your motherboard’s capacity, the chipset’s clock rate, and your CPU’s processing power, among other things.
Moreover, many applications can’t use the entire bandwidth offered by modern RAM technologies.
Therefore, it’s best not to splurge on high-frequency RAM as you’re unlikely to see gains beyond 1066 MHz with DDR3 RAM.
Instead, it’s better to buy a high-quality kit with a decent warranty, as low-quality RAM can cause extremely hard-to-diagnose errors.
Note: Multiplying your RAM’s frequency by eight will give you a rough estimate of how many bytes it can transfer per second. For example, with DDR3’s peak transfer rate of 2133 MHz, you’ll get about 17,000 MB/s.
Note 2: It’s possible to overclock your RAM exactly as you overclock a CPU or GPU, increasing the voltage and frequency. However, overclocking the RAM won’t usually translate into noticeable improvements in your programs.
RAM latency refers to how long it takes the CPU to retrieve information present on a block memory.
In other words, it’s the delay between the time that the CPU issues a command and the time that the RAM responds to that command.
Latency is measured in clock cycles.
Therefore, smaller numbers indicate better performance.
4. Memory Timings
If you’ve ever looked at a RAM stick, you’ve seen a sequence of four numbers written on it after the frequency and before the voltage.
Those numbers determine your RAM’s latency.
Before we tell you what each number indicates, know that the details are a bit geeky.
If you’re only interested in picking the right RAM for your computer, you don’t need to know these details.
To understand the sequence of four numbers on your RAM stick, you need to know how RAM is structured.
The data on RAM is divided into multiple blocks in a grid structure.
Individual columns and rows have unique identifiers.
The CPU can easily access each block using its column and row identifiers, i.e., its address.
Accessing each cell involves four types of delay (written in this order on your module):
- Column Access Strobe (CAS): The number of cycles it takes for the RAM to send the first response to a data request.
- Row Address to Column Address Delay (tRCD): The number of cycles to open a row of memory and access a column in that row.
- Row Precharge Time (tRP): The number of cycles required for opening a new row.
- Row Active Time (tRAS): The number of cycles a row must stay open to ensure that the required data is retrieved without errors.
Note: You can modify the default latency values via a profile in your BIOS settings. However, don’t make huge changes and always do a stress test such as Memtest86+ to ensure stability. You can also slightly increase your voltage to increase stability. As usual, the gain in performance won’t be noticeable, though.
Note 2: Because different RAM modules run at different clock rates, you can’t compare latency in clock cycles. Instead, the formula below gives you a way to compare modules in nano nanoseconds:
Latency in nanoseconds = (CAS Latency/ Clock Rate) X 2000
As mentioned earlier, it’s usually a better idea to install two lower-capacity sticks than a large one.
Motherboards usually support that arrangement by including channels.
In simple terms, the channel refers to the number of same-colored DIMM slots on your motherboard.
For example, if you see two black and two blue slots, your motherboard is dual-channel.
On the other hand, having four black and four blue slots indicates a quad-channel motherboard.
Note that you don’t have to populate all the channels, but you’ll get better performance if you do.
For example, to install 16 GB of RAM on a quad-channel motherboard, you should buy a quad-channel kit consisting of four 4 GB sticks for optimal performance.
If you like, you can get a dual-channel kit with two 8 GB sticks or a single 16 GB one, but your applications and games will get slightly less bandwidth.
Note: You can install a quad-channel kit on a dual-channel motherboard by populating all four DIMM slots, and in almost all cases, you won’t run into any problems. You can even adjust the timings via your system BIOS to increase performance. However, the best approach is to get a dual-channel kit for a dual-channel motherboard.
Can You Mix And Match RAMs?
The general belief is that you should buy identical sticks, but that’s usually only possible when you’re building a rig from scratch.
Fortunately, as technology has progressed, RAM conflicts have become a thing of the past.
As long as you get the right DDR version for your motherboard, you can get away with installing any two sticks with negligible decreases in performance.
If you’re interested in learning more, watch the video below:
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