A Gen 4 vs Gen 5 SSD comparison can look simple on a product page: one drive quotes twice the maximum sequential speed, so surely it is the better buy. For most UK shoppers, that is not how the value works. A Gen 5 NVMe SSD can be genuinely useful, but it often costs more per terabyte, runs hotter and delivers little noticeable benefit in everyday gaming, office work or home storage.
The right question is not which generation is fastest. It is whether the extra speed changes what you do with the PC enough to justify the higher purchase price and lower capacity you may get for the same budget.
Gen 4 vs Gen 5 SSD speed in plain English
Both are PCIe NVMe M.2 drives, usually in the familiar 2280 stick format. The generation refers to the PCIe connection between the SSD and your PC. A four-lane Gen 4 drive has a theoretical ceiling of roughly 8GB/s, while a four-lane Gen 5 drive can reach roughly 16GB/s.
Real product figures are lower. Fast Gen 4 models commonly advertise sequential reads of around 7,000-7,500MB/s. Current Gen 5 models can reach 10,000-14,500MB/s or more. That gap matters when moving huge files, but headline sequential figures are not a reliable guide to every job.
Launching Windows, opening a browser and loading many games depend heavily on random reads, CPU performance, memory and the game engine. A decent Gen 4 drive already makes these tasks feel quick. In side-by-side use, the difference between a good Gen 4 SSD and a Gen 5 model can be seconds, fractions of a second, or impossible to notice.
Gen 5 starts to make more sense if you regularly work with large video files, high-resolution photography catalogues, virtual machines, software builds or local data sets. Copying hundreds of gigabytes between two suitably fast drives is a more credible Gen 5 use case than shaving a little time from a game loading screen.
The value gap matters more than the speed gap
Storage buyers should compare like for like: the same capacity, condition and drive type. A 1TB Gen 5 SSD may have a tempting headline price, yet a 2TB Gen 4 SSD can often provide more useful storage for a similar outlay and a much lower £/TB figure.
That capacity difference has practical consequences. Modern games can exceed 100GB, RAW photo libraries grow quickly, and an SSD performs best when it is not filled to the last few gigabytes. Buying the faster 1TB option can mean paying for a drive that is technically superior but forces you to manage space sooner.
When comparing current listings, calculate:
- the total price including delivery where applicable
- price per terabyte, using the advertised usable drive capacity
- whether the drive is new, used or refurbished
- whether a heatsink is included and whether your motherboard needs one
- the capacity tier, because 2TB and 4TB drives often offer better £/TB than 500GB or 1TB models
Price movements matter too. A Gen 5 drive at a modest premium may be worth considering, especially for a new high-end build. If the Gen 5 version costs substantially more per TB than a reputable Gen 4 alternative, the money usually buys more real-world benefit when spent on extra capacity, system memory or a better graphics card.
TerabytePrices-style comparisons are useful here because the cheapest listing is not automatically the best storage deal. The meaningful comparison is the current £/TB across suitable drives, then the performance premium for your workload.
Compatibility can make Gen 5 a poor purchase
A Gen 5 SSD will work in a Gen 4 M.2 slot, but it will run at Gen 4 speeds. You do not get Gen 5 performance simply because the label on the drive says PCIe 5.0.
To use its full bandwidth, your motherboard and processor must provide a PCIe 5.0 M.2 slot. This is more common on recent enthusiast desktop platforms than on older PCs, budget boards and laptops. Check the motherboard manual rather than assuming every M.2 slot is Gen 5. A board may have one Gen 5 slot and several Gen 4 slots, or its lane arrangement may affect other expansion hardware.
For a laptop upgrade, Gen 4 is normally the sensible target. Many laptops support only Gen 4, have limited cooling room and may not accommodate a thick SSD heatsink. A Gen 5 drive will still function in many cases, but you would be paying for speed the machine cannot use.
There is also a future-proofing argument, but it has limits. Buying a Gen 5 SSD now for a future motherboard means accepting today’s higher £/TB without receiving its main benefit until you replace other hardware. By then, Gen 5 prices may have fallen and newer drives may offer better capacities or efficiency.
Cooling, noise and sustained performance
Gen 5 SSDs tend to use more power and generate more heat than Gen 4 models. Many high-speed versions ship with substantial heatsinks, and some need active cooling under heavy sustained workloads. That is less of a concern in a roomy desktop with good airflow, but it is relevant in compact cases and workstations where several components already run warm.
Heat does not merely affect comfort. If an SSD gets too hot, it can reduce its speed to protect itself. A drive that posts a spectacular benchmark result but throttles during a long transfer may not deliver the advantage you expected.
Gen 4 drives can also benefit from a motherboard heatsink, particularly faster models, but their cooling demands are generally easier to manage. For a PlayStation 5 upgrade, a compatible Gen 4 drive with an appropriate heatsink remains the practical choice. The console does not gain a benefit from Gen 5 storage.
Do not judge an SSD by PCIe generation alone
Two Gen 4 drives are not necessarily equal, and the same applies to Gen 5. Controller quality, NAND type, cache design, firmware, warranty and sustained-write behaviour all influence the experience.
A cheaper QLC drive may offer an attractive £/TB figure and be perfectly suitable for game storage, documents or a secondary PC. However, it can slow down sharply after its fast cache is exhausted during long writes. A TLC model is usually the stronger choice for frequent large transfers, editing work or a primary drive that receives regular heavy use.
Likewise, a budget Gen 5 SSD is not automatically a better performer than a premium Gen 4 drive in every workload. Look beyond the maximum read number. Check write ratings, endurance measured in TBW, warranty length, heatsink requirements and independent sustained-performance testing where available.
Capacity can alter performance within the same range as well. A 2TB version may write faster and last longer than the 1TB version because it has more NAND chips working in parallel. Always compare the specifications for the exact capacity in your basket, not only the family name on the listing.
Which buyers should choose Gen 4 or Gen 5?
Choose a Gen 4 SSD if value is the priority
Gen 4 is the default recommendation for gamers, students, home-office PCs, PS5 owners and most mainstream desktop upgrades. It offers very fast everyday performance, wide compatibility and usually a better chance of finding 2TB at a sensible £/TB.
It is also the straightforward choice if your PC has only Gen 4 M.2 slots. Spend within the generation your hardware supports, then focus on capacity, warranty and whether the particular drive suits your write workload.
Choose a Gen 5 SSD if time is part of your job
A Gen 5 SSD is easier to justify for a new compatible desktop used for professional video editing, frequent multi-hundred-gigabyte transfers, development work, virtual machines or data-heavy creative projects. In those cases, minutes saved repeatedly can be worth more than the extra cost.
It can also suit enthusiasts building a high-spec PC who understand the cooling requirement and accept a higher £/TB. That is a valid preference, but it is a performance purchase rather than a storage bargain.
Before paying the Gen 5 premium, compare current 2TB prices rather than fixating on the lowest advertised entry price. For most buyers, a well-priced 2TB Gen 4 TLC drive with reliable cooling is the upgrade that will feel useful every day - and leave fewer files waiting for somewhere to go.