What should I look out for when buying RAM?
The latest generations of DDR4 RAM clock in at around 2,400MHz. Gamers will want DDR4 memory that operates at speeds of around 3,200MHz for Intel chips and 3,600MHz for AMD chips. Other users (such as professional programmers, multimedia editors, and hardcore gamers) may look for higher clocked memory with speeds up to 4,800MHz from specialist manufacturers like G.Skill or Corsair.
Clock speeds are one thing, but another important factor to consider when buying RAM is latency — the time delay between when a command in memory is entered and when it’s executed. The lower the latency, the higher the performance.
For high-level performance, you’ll need memory above 4,000MHz with a latency of around CAS (Column Address Strobe or Signal) 15-18 or less. When buying RAM, you might see this listed as CL 16 (Column Latency 16), for example. For regular users, this is unlikely to make a meaningful impact, but gamers should take note.
Keep in mind the 32-bit Windows versions
Finally, you can’t just install infinite amounts of RAM in your PC and expect it to work. In order to use more than 4GB of RAM, you need to run a 64-bit version of Windows — 32-bit versions are limited to 3.5GB of memory only. If you’re still using the 32-bit edition of Windows 7, you’ll need to upgrade to 64-bit Windows to use 4GB of RAM or more.
But, note that installing a 64-bit version of Windows on an old machine with less memory may have a negative impact. Addresses in Windows are now 64 bits long, rather than just 32 bits. This means a larger memory footprint for each application. Depending on which applications you use, Windows 64-bit might use 20–50% more of your memory. So running a 64-bit version makes sense only if you have larger system memory.
On today’s PCs, Windows 10 64-bit (and now Windows 11) is installed by default and will work very fast on PCs with 4GB of RAM or more.
