I picked up my first NVMe SSD without much thought. I just grabbed one with good reviews and that fit my budget. This upgrade to my old PC made it feel brand new, and it worked fine. But I realized I’d been ignoring many important factors that could’ve saved me money and improved performance.
Shopping for NVMe SSDs has got more complicated than it used to be. With different PCIe generations, form factors, and specs thrown around, it’s easy to get overwhelmed or miss important details. I also upgraded my newer PC in 2025 with a better NVMe. I’ve learned that checking a few key things before buying improves the chances of getting the right drive for your needs.
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PCIe generation
Backward compatibility doesn’t mean you get the same speed
PCIe generation is the first thing I check now when buying an NVMe SSD. The generation determines the maximum speed your drive can reach, but there’s a catch. You actually need a motherboard that supports that generation to get those speeds.
There are three main PCIe generations you’ll see, which are 3.0, 4.0, and 5.0. Each generation roughly doubles the bandwidth of the previous one. PCIe 3.0 x4 (with 4 PCIe lanes) maxes out around 3,500 MB/s, while 4.0 x4 can hit 7,000 MB/s, and 5.0 x4 theoretically reaches 14,000 MB/s.
I’ve seen people buy expensive PCIe 5.0 drives only to plug them into PCIe 4.0 slots—that’s a waste of money. The drive will work due to backward compatibility, but it’ll run at 4.0 speeds. You’re paying a premium for performance you can’t access. Check your motherboard’s PCIe generation before buying. You can find this in your motherboard manual, in your system BIOS, or with software like CPU-Z. Understanding the differences between PCIe generations helps you make a smarter choice.
Though for most daily tasks, such as web browsing, gaming, and regular file transfers, it’s hard to notice any difference between 4.0 and 5.0. The PCIe 5.0 drives also cost significantly more and generate more heat. Unless you’re doing heavy video editing or working with massive datasets, PCIe 4.0 offers the best balance of performance and value right now.
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Form factor
Check the size to avoid compatibility issues
Form factor sounds technical, but it’s just the drive’s physical size. If you get this wrong, the SSD won’t fit in your slot. M.2 SSDs come in different sizes, labeled with four-digit numbers. The most common is 2280, which means 22mm wide and 80mm long. You’ll also see 2242 (42mm long), 2230 (30mm long), and 22110 (110mm long), though these are less common.
Most desktop motherboards support multiple form factors and will have mounting holes for different lengths. Check to confirm which sizes fit your specific slot. On the other hand, laptops can be pickier—they often only accept one size, and some lighter laptops use the smaller 2230 form factor to save space.
Another thing to watch for is that single-sided drives have chips on only one side, while double-sided drives have them on both sides. Thin laptops with tight clearances might not fit double-sided drives, which is why some people avoid thin and light laptops. Product listings usually specify the form factor in the title or specifications section—look for those four-digit numbers before buying.
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Speed ratings
Those big numbers on the box aren’t the full story
Speed ratings on product pages look impressive, but they might not reflect what you’ll actually experience. Manufacturers advertise sequential read/write speeds. These are the numbers you see in big bold text because they’re the highest figures they can claim.
Sequential speeds measure how fast the drive transfers large, continuous files. That’s handy for moving heavy video files or game installations, but it’s not what happens during normal use. Random read/write speeds matter more for daily tasks like loading apps, booting your OS, and opening games. Random speeds are measured in IOPS (Input/Output Operations Per Second). This tells you how quickly the drive handles small, scattered files—the kind of activity that dominates everyday computing. A drive with 7,000 MB/s sequential speed but low IOPS may feel slower than one with 5,000 MB/s and high IOPS.
Another issue is that many drives use QLC (Quad-Level Cell) NAND, which is cheaper but slows down during sustained writes. TLC (Triple-Level Cell) maintains better performance under load. If you’re regularly doing video editing or transferring large files, an SSD with TLC NAND is a better choice for you.
Don’t chase the highest sequential numbers. Instead, look at random speeds, IOPS, and the NAND type. For gaming and general use, a mid-range drive with solid random performance beats an expensive flagship with inflated marketing claims.
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Thermal management
Hot drives slow down when you need them most
Fast NVMe drives generate a lot of heat, especially PCIe 4.0 (also interpreted as Gen 4.0) and PCIe 5.0 models. When they hit around 70°C or higher, they thermal throttle and eventually slow down to protect themselves. This tanks the performance right when you need it most. That’s why it’s best to add a heatsink to improve your NVMe SSD’s performance.
Some NVMe drives come with a pre-installed heatsink, which is convenient. Also, most modern motherboards already have an M.2 heatsink built in, and anything from B550/Z590 and newer usually does. If your motherboard has one, a pre-installed drive heatsink can interfere with the motherboard’s M.2 coolers. Therefore, check the clearance before choosing a heatsinked drive, as it may not fit under your motherboard’s cooling solution unless the heatsink is removable.
For PCIe 3.0 drives or systems with light workloads, you can often skip the heatsink if your case has decent airflow. These drives don’t get as hot as their PCIe 4.0 and PCIe 5.0 counterparts.
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DRAM cache
This spec makes a bigger difference than you’d think
DRAM (Dynamic Random Access Memory) cache is one of those specs that doesn’t get much attention, but it makes a noticeable difference in performance. DRAM stores the drive’s mapping table, which tells the SSD where your files are located. This speeds up access times.
Drives without DRAM, called DRAM-less drives, use your system’s RAM via HMB (Host Memory Buffer). This works, but it’s slower and less efficient. The performance gap shows up when handling small files, loading applications, or multitasking heavily.
For everyday use, such as web browsing and streaming, DRAM-less drives are acceptable. I’ve used them as secondary storage for games and media files without issues. However, I wouldn’t recommend one as an OS drive or for workloads that involve frequent small-file operations.
Sadly, manufacturers don’t always list DRAM clearly in specifications. You’ll often need to check reviews or spec sheets from third-party sites to confirm. Some budget drives skip DRAM to cut costs, which makes sense for secondary storage but hurts performance where it counts. DRAM drives cost more, but they offer better consistency and longevity. If you’re installing your OS or using the drive for heavy workloads like video editing, the extra cost is worth it.
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Endurance rating
Ensure your drive lasts
Endurance ratings tell you how much data you can write to the drive before it wears out. This is measured in TBW (Terabytes Written) and used to estimate the SSD’s remaining lifespan. A 500GB drive might have a rating of 300 TBW, meaning you can theoretically write 300 terabytes before the drive degrades.
The type of NAND affects endurance. MLC (Multi-Level Cell) lasts longer but costs more. TLC (Triple-Level Cell) offers a good balance of endurance and price. QLC (Quad-Level Cell) is cheaper but wears out faster. However, most people never hit their drive’s TBW limit. For general use, such as gaming, browsing, and streaming, even a QLC drive will last for years.
Endurance matters more if you’re a content creator, run databases, or constantly write large files. In those cases, you may prioritize TLC over QLC and look for higher TBW ratings. The warranty period usually correlates with TBW—longer warranties indicate better endurance.
After buying, you can monitor the drive’s health to see how much life it has left. Tools like CrystalDiskInfo show remaining lifespan and help you get more performance from your NVMe SSD through optimization.
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Price per gigabyte
The cheapest drive isn’t always the best deal
The price per gigabyte is a simple calculation that tells whether you’re getting a good deal. Divide the total price by the capacity in gigabytes—a $100 1TB drive costs $0.10 per GB, while a $180 2TB drive costs $0.09 per GB.
Usually, when it comes to capacity, the sweet spot for value is 1TB, with 2TB as a close second. Smaller capacities like 500GB often cost more per gigabyte, while massive drives like 4TB carry a premium that doesn’t always justify the extra cost.
That said, price shouldn’t be your only consideration. Budget brands occasionally offer tempting prices, but skimping on reliability to save a few dollars isn’t worth it if the drive fails early. I’d rather pay slightly more for a brand with solid reviews and warranty support.
If you’re not in a rush, sales events like Black Friday and Prime Day can drop prices by 20-30%. However, don’t chase the cheapest option if it sacrifices DRAM, endurance, or thermal management—balance price with the other factors we’ve covered. Also, be wary of flagship models with diminishing returns. A $300 PCIe 5.0 drive might benchmark faster than a $150 PCIe 4.0 model, but you won’t notice the difference in most real-world tasks.
Making the right choice
Buying an NVMe SSD doesn’t require checking every spec, just the ones that affect your experience. Match the PCIe generation to your motherboard, verify the form factor fits, and prioritize random speeds over sequential numbers.
For most people, including me, a 1TB PCIe 4.0 NVMe drive with DRAM offers the best balance. Content creators might want higher endurance, while budget builders can skip DRAM for secondary storage. It’s about understanding what you’re paying for, rather than unthinkingly chasing the highest specs or the lowest prices.