Tips for buying computer memory

Many years ago, I wrote something titled Memory Buying Secrets. That post is lost to history, thanks to migrations in this site’s early years, but there are a number of things you need to know when you’re buying memory that can save you money and frustration, so I figured I would revisit that topic today. Here are my tips for buying computer memory, based on decades of experience.

Pricing is volatile

Memory pricing changes a lot over time. You can search Camelcamelcamel for major types of memory–say, for Crucial 16gb DDR3–to view historical pricing. If pricing is at historical lows, buy a bunch. If pricing is at a peak, you may want to wait a little while if you can. Another option is to buy enough to get you by and upgrade when prices are lower.

Pricing can change for any number of reasons. Fabrication plants can go offline due to natural disasters, and that will cause prices to rise. A highly anticipated new product, such as a new video game console or tablet, can soak up a lot of the market and cause prices to go up. When the industry starts to transition to a new type of memory, like what’s happening right now with the transition from DDR3 to DDR4, prices can rise. When a market stabilizes on one type of memory, such as in 2012 when everything was using DDR3, prices can drop.

Volatility is the reason only five companies make memory chips anymore. Three of those five dominate.

Brand names matter

Miscellaneous computer memory.
The module on the far right has Samsung chips on it, but you’ll need more than the markings on the chips to know who actually made the module. Make sure it’s someone reputable.

I wrote a lot about that many years ago, and what I said then is still true today. Here’s a synopsis. The name brand on the memory chips themselves doesn’t matter, but the brand on the module itself does. Only five companies make memory chips today–Micron, Samsung, and Hynix, Nanya, and Winbond. Of those, only Micron (through its Crucial subsidiary) and Samsung make modules that you’re likely to be able to buy in stores. Just because a loose module has chips on it that bear a certain brand name doesn’t mean the same company made the module.

In the mid 1990s, I bought whatever memory was cheapest. They failed at an atrocious clip–about 1 in 12 of those questionable modules failed on me. So I started buying memory from Crucial and Kingston almost exclusively. When buying name-brand memory, I’ve experienced failure rates of 1 in 1,000, which is much better.

I personally buy and recommend Crucial, Samsung, and Kingston memory. But you can do OK with other name brands as well. Companies like G.Skill, EVGA, Corsair, and PNY that make a lot of other peripherals know how to make good memory too. If the price difference is only a few dollars, I’ll buy one of my top three. I always prefer my top three. If I find a bargain on another brand, I’m willing to consider it. But I’m not willing to take chances on unbranded or house-brand memory.

With a good brand, the difference between value and premium memory is performance

As long as you’re buying brand-name memory, there’s no major difference in quality between their value line and their costlier lines. As long as value memory is fast enough for your computer’s motherboard, there’s no problem with using it. The caveat is that if your computer supports fast memory and can take advantage of it, your computer will run faster with the better memory. It doesn’t make sense to buy the fastest Core i7 CPU and then tie it down with PC3-6400 memory. And PC3-14900 memory will probably be wasted on a Celeron, though it will work fine.

Match your memory

Memory is very timing-sensitive, so for best stability, make sure all of the memory in your system is the same speed. If you can’t match it exactly, buy memory that’s faster.

One thing I will say for buying from Crucial is that their branding makes matching very easy. If I bought Crucial Ballistix Sport DDR3 memory one year, I can buy the same type years later and know the memory will match exactly, down to the maker of the chips.

Heat sinks don’t matter

Heat sinks are a marketing gimmick, because DRAM doesn’t get all that hot. The one nice thing about them is that it makes it easy for a module maker to print a brand name on it, which means you can go back and buy the same thing again in a few years just by checking the existing modules. And it probably increases resale value a little because the perceived value is a bit higher.

But heat sinks don’t actually do anything to improve reliability, so don’t pay extra for fancy heat sinks. A module from a reputable manufacturer that doesn’t have heat sinks on it will still provide years of reliable service.

How to install memory

Memory performs best when in pairs, or on high-performance boards, in threes. Many motherboards will color-code their memory sockets. When that’s the case, install identical modules in like-colored banks. If your memory sockets aren’t color coded, look to see if the banks are marked on the motherboard. If there’s no text printed on the motherboard, refer to your manual.

When you install memory in perfectly matched groups, the computer can interleave data between modules. That speeds up memory access, and thus speeds up performance.

How to test memory

When you buy new memory, it’s a good idea to test it for 24 hours. Two good ways to test it are to run Memtest86 on it (the free version is fine), or to run Prime95, which you can run from your workaday operating system and continue to use your computer. If you run one or the other of those and get errors, exchange the memory.

Memory speeds

Memory is measured with a numeric number that starts with the letters PC, such as PC3-12800. If you can’t find PC3-12800, you can buy a faster speed, such as PC3-14900, and it will run at the slower speed without issues. But if you buy slower PC3-10600, your computer may run all of your memory at the slower speed. Or it may try to run the slower memory at the higher speed, which can affect stability.

So it’s always best to see what speed of memory your PC or motherboard manufacturer recommends and buy the same speed. Better yet, find out the speed of what’s already in your computer (it will often be on a sticker on the module), and buy something identical. If you’re in doubt, Crucial’s System Scanner, which you can download directly from, is a great tool to get advice on the right memory to buy.