DDR3 vs. DDR4

Which form of RAM is right for your computer?

DDR3 has been one of the most common forms of computer memory for a long, long time. However, it's steadily being replaced by DDR4. Here are the differences between DDR3 vs. DDR4 and some information on why those differences matter.

DDR3 vs. DDR4: Overall Findings

DDR3
  • Debuted: 2007

  • Maximum Size: 8GB per module

  • Operating Voltage: 1.5v

  • Lowest Speed: 800 Million Transfers Per Second (MT/s)

  • Latency: 12.5 milliseconds

DDR4
  • Debuted: 2014

  • Maximum Size: 16GB per module

  • Operating Voltage: 1.2v

  • Speed: 1600 Million MT/s

  • Latency: 12.75 milliseconds

The best way to think of DDR3 and DDR4 is like different versions of Windows, instead of competing products. “DDR” stands for “double data rate” and is a standard. While there may be some variety between different brands, each brand will conform to the standard. The numbers refer to the version of the standard, with DDR4 being the latest version. While one type of RAM is usually the same as another, remember that you should stick with one brand when replacing RAM.

DDR3 and DDR4 standards use different pin sets in motherboards, so a motherboard compatible with DDR3 will not be compatible with DDR4 and vice versa. Any computer built between 2007 and 2013 will only be compatible with DDR3 and perhaps DDR2. For any computer built in 2014 or later, you'll need to consult your computer's owner's manual.

This question mostly comes up when you're debating replacing an old device, or refurbishing a yard sale find for purposes like running a print server or maintaining a home network, where you may consider replacing DDR2 RAM with DDR3 in certain situations.

DDR3 Pros and Cons

Pros
  • Low cost.

  • Well-understood, with few bugs and errors.

  • Can improve the speed of older devices.

Cons
  • Incompatible with some CPUs.

  • May require application upgrades and drivers.

  • Motherboard will need a DDR3 pin configuration in order to work.

  • Will become more difficult to find over time.

Just like DDR3 and DDR4 have incompatible pin design, the same is true of DDR2 and DDR3. However, there are some motherboards that have slots for both, which are usually found in computers manufactured around 2007, when DDR3 first arrived. Whether or not you can upgrade will be dictated by the motherboard in your device.

That said, there are benefits to upgrading if you can do so. Keep in mind that your CPU will need to be compatible with DDR3, and that not all of the applications and tools you use will necessarily be built to support it. But while these are a lot of hoops to jump through, it can help you keep an old device up and running for longer, and might be worth considering in specific situations. However, it will become harder to find as it becomes more and more outdated.

DDR4 Pros and Cons

Pros
  • Fastest RAM currently available.

  • Largest module sizes.

  • Will work with all current motherboards.

Cons
  • Higher price.

  • Performance will be CPU-dependent.

  • Due to be replaced in 2020.

Replacing DDR3 with DDR4 isn't generally an option. A very small number of motherboards support both chipsets, but those are rare and haven't generally been used in consumer devices in order to keep costs down.

The main problem with DDR4 is it's about to be replaced. The Joint Electron Device Engineering Council (JEDEC) Solid State Technology Association, which controls the DDR standard, has announced that the fifth version of the standard, DDR5, should be available to manufacturers in 2020, two years after it was first planned to be published. While there will still be uses for DDR4 RAM, expect it to start phasing out in 2020 in high-end products, filtering down quickly to consumer-grade devices.

Final Verdict: Wait For the Next Version, If You Can

Whether or not you upgrade your RAM will depend on some very specific circumstances. If you're considering whether to upgrade an old device or trade it in for a new one, though, if you can wait for DDR5, you'll probably be better off.