DON’T BUY THEWRONG TYPE OF MEMORY
Do youneed DIMM or SO-DIMM? DDR3 OR DDR4? Find out...
If your computer is suddenly running more slowly than before and its drop in performance can’t be explained by demanding software you’ve recently installed, it may be that your PC’S memory modules are faulty.
First, run a full scan with your antivirus software to rule out malware. If this throws up no problems, open the Start menu, type windows memory diagnostic and press Enter. Your PC will restart and test the health of your memory modules (you can follow its progress – see screenshot below).
Once it’s complete, Windows will load as normal and show a pop-up message with the test result. If this is anything other than ‘No memory errors were detected’, your memory almost certainly needs to be replaced. Alternatively, you may simply want to add more memory to improve your PC’S performance (we recommend a minimum of 8GB).
Whatever your reasons, follow our advice on choosing and installing the correct memory to avoid costly mistakes.
Before we go any further, it’s a good idea to confirm how much memory your PC has. Press the Windows key+i to open Settings, then click System followed by About in the left-hand menu and check the Installed RAM section (see screenshot above).
Types of memory
Memory chips are faster and smaller than ever, letting you store more data without the modules taking up more space inside your computer. The way they physically connect to your computer has also changed, which is why it’s important to make sure you’re buying the right type of memory for your device.
In general, there are two types of memory. SRAM (static random access memory) is incredibly fast, can be built into other components like your processor, and is used to briefly store data that your PC will use immediately. DRAM (dynamic random access memory) is slightly slower and used for storing data for a longer period of time. It’s this DRAM that you’ll be replacing when you upgrade your memory modules.
In almost every case, you’ll need to buy a type of DRAM known as SDRAM. The ‘S’ here stands for ‘synchronous’, meaning data moves on to and off the memory chips at regular intervals, which are determined by the clock speed of your processor.
The first SDRAM was single-data rate (SDR) memory, which appeared in the mid-1990s and could transfer data only once at every ‘tick’ of your processor’s clock (a 133MHZ processor ‘ticked’ 133 million times every second, which was considered fast at the time).
By the late 1990s this had been superseded by double data rate (DDR) memory, which transfers data twice for every tick of your processor’s clock. There have been several generations of DDR memory since, with the latest standard – DDR5 – arriving in July 2020. As a rule, the later the generation, the faster the memory, but don’t go straight out and buy DDR5 because your computer might not be compatible.
Within these DDR standards, there are subgroups such as registered and unregistered memory sticks – the former are abbreviated to RDIMM, and the latter to UDIMM or simply DIMM (Dual In-line Memory Module). We won’t get bogged down in the differences, suffice to say almost all desktop PCS use DIMM/ UDIMMS (only business servers use RDIMM modules).
If you’re upgrading a laptop, or a mini desktop PC that uses laptop components,
you’re more likely to need SO-DIMM (the ‘SO’ stands for Small Outline), which are physically smaller than DIMM/UDIMMS (both pictured above).
Buy the correct memory
For a detailed overview of your existing memory, open Command Prompt (press the Start button, type cmd, then press Enter). Next, type wmic memorychip get configuredclockspeed, configuredvoltage, manufacturer, partnumber (copy this command from our Pastebin account at www.snipca.com/37264), then press Enter. This show your existing memory’s speed, voltage, manufacturer and part number (see screenshot below).
Armed with this information, you can search online stores for the part number and use the speed and voltage values to verify that you’ve identified the correct module. You can then either buy a direct replacement if your memory is faulty or compatible modules if you want to increase your PC’S memory.
Alternatively, you can let memory manufacturer Crucial’s scanner do the hard work for you. This not only checks what memory your computer currently has, but also recommends compatible upgrades. You can download the free tool from www.snipca.com/37223 – you’re not committed to buying Crucial products on the back of its results.
When we ran a check on our laptop, the suggested module was out of stock at Crucial, but clicking the ‘Where to buy’ button beside each option gave us links to third-party suppliers, including Amazon.
You can’t mix different generations – DDR3 and DDR4, for example – because your motherboard will only have slots for one or the other. You can, however, mix and match speeds, so if you can only buy memory that’s faster than your existing chips, pairing the two won’t be a problem. Be aware, though, that all modules will adjust to match the speed of the slowest, which means that installing slower memory than you already have could reduce the overall performance of your PC, even though it has more memory installed.
Install your new modules
Some PC manufacturers solder memory directly on to the motherboard. This can’t be replaced, but it’s more likely the memory in your PC takes the form of small cards – or sticks – that fit into dedicated slots. To make sure they’re correctly inserted, the contact edge will feature a notch, just offset from the centre (see photo left), which makes it physically impossible to insert them the wrong way. The position of these notches depends on the generation – so DDR2 memory won’t fit into a DDR4 slot, for example.
Turn off your computer and leave it for a while to cool down, then earth yourself (for example, by touching the pipe going into a radiator). Next, remove your PC’S side panel. On a laptop, it’s best to check your manual or the manufacturer’s website (some laptops require you to remove the entire underside, others just a panel).
Because memory is susceptible to damage by static electricity, your new modules should be supplied in an anti-static bag. Once you’ve identified the relevant slot on your motherboard, hold the memory (still in the bag) alongside it so you can orientate it correctly. Only once you know which way it slots in should you remove it from the bag and insert it. You’ll normally need to insert it almost vertically, then reduce the angle until it’s secured by the integrated clips at either end of the slot. Avoid touching any of the contacts on either the memory or the motherboard - although unlikely, this can cause damage.
When you reboot your computer, Windows should detect the new memory. Return to the System section of the Settings app (as explained earlier) to check. If you hear any beeps and your PC refuses to boot, make sure all memory modules are securely in place.