Most people find it easy enough to figure out how much memory to put in their PC. Memory speed, however, is more of a mystery.
You may know that having more gigabytes of RAM is a good thing but does the same apply to RAM speed?
And on a related topic, what are RAM timings and what should you be doing about it?
Speed Ratings Explained
It helps to know what the speed ratings on your memory module mean and how much they matter. The speed ratings on your RAM module correspond to its data transfer rate. This is how much data throughput it can handle each second. The faster it is, the faster your computer can store and retrieve data from local memory.
The speed rating is commonly labeled in DDR2/3/4 terms such as DDR4-2666. This number is the capacity expressed as a million bytes per second. Sometimes we also see the older PC2/PC3/PC4 terms. These are the capacity expressed as a million bits per second so DDR4-2666 would be PC4-21328.
In general, it is better to stick to the DDR standards to avoid unnecessary confusion. DDR stands for “Double Data Rate.” With each new version of the DDR, the memory bus and speed capacity of the RAM module are increased leading to better performance.
The most current version is the DDR-4 RAM speed although the DDR-3 RAM is often used in older or cheaper PCs. Obviously, the higher this number is, the faster the rate is and the better it is for you.
Along with speed ratings, RAM also has ratings for timing.
This appears as a string of numbers such as 9-9-9-24. These numbers are indicators of latency which is the number of clock cycles it takes your RAM to do things. This could mean the speed at which the RAM module can access data from rows and columns of the memory array or how quickly it can access its hardware.
In this case, it is best to look for lower numbers, meaning the RAM takes lesser clock cycles and thus faster data access. More expensive RAM or high-quality RAM often has low latency and high speed.
So, a combination of timings and speed will determine how fast your RAM will run and, similar to a CPU or video card, you can also overclock your RAM.
Does RAM Speed Matter?
Unlike processor overclocking, which would bring you noticeable performance gains, getting the fastest possible RAM for your system is often a waste of money. The higher speed, lower latency for RAM does give your PC performance boosts but these are at such a fundamental level that they cannot be detected unless you are using specialized benchmarking software. Humans will hardly be able to notice a difference.
While faster RAM will improve your PC in certain areas, it is always practically better to get more RAM than faster RAM. For example, if you are confused about your RAM speed for gaming, prioritize capacity over speed.
Speed may be important for certain games and systems but you need to have enough memory to support the game graphics. Especially if you are dealing with a more discrete graphics card, your PC will depend more heavily on RAM capacity.
Always choose a 16GB RAM over an 8GB one. A DDR-4 RAM with a speed rating of 2400 MHz would be quite sufficient. RAM faster than this would be useful for a high-traffic server or virtual host but for most modern users it wouldn’t matter as much.
Compatibility Issues and Potential Pitfalls
It’s important to know that DDR standards are not compatible backward or forwards. A PC rated for DDR-3 RAM modules will not be compatible with DDR-2 or 4. Even the slots will not match. The pin configurations will not allow for the wrong module to be installed.
There’s also something to be said about the differences in compatibility between RAM speed and latency. You can optimize your memory performance just by knowing this relationship a bit better.
Largely, there are two standards, or specifications, that categorize memory and allow us to detect and configure it. These two are the JEDEC and SPD standards. The JEDEC Standards help all vendors agree on specific settings for any one type of RAM – let’s say DDR3-12800 – for everything from the cycle-time to the clock-speed and so on.
On the other hand, the motherboard implements the SPD Standards.
SPD stands for Serial Presence Detect, meaning that the motherboard expects the RAM to correspond to one of the JEDEC profiles for the configuration expected from that RAM type. Hence, the statements you would see of motherboard manufacturers supporting “up to DDR3-18000”, for example, would mean that that motherboard has SPD that can recognize any RAM of the DDR3 type with a transfer rate up to 18000, and it can load up the JEDEC profile needed to use it.
Thus, the further away you move between two RAMs of different speeds and timings, extra stress is going to be exerted on your motherboard to keep them both running at the same time. This would not be the case with one mismatch – if only the CAS timings were different and the speeds were the same, your motherboard could easily run both of them at a slower speed.
So, while a RAM is easily compatible in itself with another RAM that holds different speeds and timings on paper, it may need to be compensated for by your motherboard. You’d also need to override the settings to gain manual control to underclock the modules to make up for the mismatch, ensuring stability.
To sum up and conclude, take some pointers home with you if you’re looking for gaming suggestions:
- Studies and tests have shown that out-the-box speeds are immaterial when it comes to their in-game performance: if you don’t want to mess with the timings yourself, go for a 3000MHZ+ kit, the cheapest one you can get your hands on.
- Tests also showed that tighter timings were responsible for increasing factors such as FPS in games, to an exponential degree (without, of course, upgrading the GPU).
- These results also showed that, if you do want to go tightening the times, opt for 3200MHZ still (over 3600MHZ), and maximize in-game performance by tuning in the timings yourself.