When considering upgrading PC storage, it's easy to fall into the trap of only looking at NVMe SSD speed figures and thinking that more is always better. The arrival of NVMe PCIe 4.0 and now Gen5 SSDs has significantly boosted theoretical read and write speeds. But the truly important question is: when are these improvements noticeable in everyday use, and when are they just marketing hype?
In the specific case of Gen4 NVMe SSDs, they are often marketed as an essential upgrade from Gen3. However, in many scenarios, the actual user experience barely changes by a few seconds , especially in gaming or everyday tasks. Let's take a closer look at when a Gen4 NVMe SSD doesn't offer real improvements over a Gen3, what happens with technologies like RTX IO/DirectStorage, and in what situations it's worth spending more.
PCIe 3.0 vs PCIe 4.0: What Really Changes
Before getting into practical examples, it's important to understand the technical differences between an NVMe PCIe 3.0 SSD and a PCIe 4.0 SSD . In short, the PCI Express 4.0 interface doubles the bandwidth per lane compared to PCIe 3.0. Thus, an x4 drive can go from a theoretical maximum of around 3.500 MB/s in Gen3 to over 7.000 MB/s in Gen4.
This translates to current mid-to-high-end NVMe Gen4 SSDs achieving sequential read speeds of 5.000 to 7.000 MB/s . This is more than the best Gen3 drives, which hover around 3,000-3,500 MB/s. On paper, the leap is enormous, but these values ​​are theoretical peaks measured under highly controlled laboratory conditions : ideal temperatures, high-end hardware, and no other system loads.
In a typical PC, many factors can reduce that advantage: the motherboard, the processor, the cooling and airflow management , the ambient temperature, the quality of the SSD controller, the type of NAND flash memory, the firmware, and even the case's placement and airflow . All of this means that the actual difference between advertised and real performance can vary considerably.
Another point to consider is that the first generations of platforms with PCIe 4.0 (both motherboards and CPUs) were somewhat underdeveloped. In those early days, support wasn't fully refined, and many systems didn't take full advantage of the bandwidth of Gen4 SSDs. This left some of their potential untapped . While this has been addressed with current platforms, it remains relevant when discussing older systems.
Compatibility: Use a Gen4 SSD on a PCIe 3.0 motherboard
A very common question is whether a PCIe 4.0 SSD can be installed on a motherboard that only has PCIe 3.0 slots . The answer is simple: yes, they are backward compatible. The Gen4 SSD will work without problems, but at the maximum speed allowed by the system's Gen3 interface.
From a practical standpoint, this means that an SSD that could reach 7.000 MB/s on a Gen4 motherboard will be limited to around 3.000-3.500 MB/s at most on a Gen3 motherboard . The drive isn't damaged or anything like that; it simply can't "run" faster than the motherboard's bandwidth allows.
This compatibility is interesting for future-proofing. If you buy a Gen4 SSD now and later upgrade your motherboard and processor to a platform that supports PCIe 4.0, you'll be able to take full advantage of its potential . But if you don't plan on changing your platform in the medium term, there's no need to spend more just because it's Gen4.
Is an NVMe Gen4 SSD enough for gaming?
The gaming sector is where the most confusion arises regarding SSD specifications. Switching from a mechanical HDD to an SSD, even a SATA one, represented a massive leap forward (and redefined the need for SSD defragmentation ): Windows boots in seconds , loading screens are significantly shorter, and the system feels much more responsive. However, the upgrade from SATA SSDs to NVMe Gen3, and then to Gen4, no longer provides such a dramatic improvement.
Loading time tests in games like Shadow of the Tomb Raider or Counter-Strike: Global Offensive show that the difference between a good PCIe 3.0 SSD and a 4.0 SSD is usually just a few seconds. Often less than 3. Under normal conditions, that's hardly noticeable while playing. We're not talking about going from a minute to ten seconds of loading time, but rather 15 versus 12, for example.
Even when comparing different models within the same generation, the differences are small. In tests with SSDs like the Corsair Force MP600, GIGABYTE AORUS NVMe Gen4, and Sabrent Rocket 4.0 (all Gen4) against a Samsung 970 Pro or an Intel Optane 905P (Gen3), game and operating system boot times were very similar, with variations of only a few seconds.
Therefore, for gaming, a Gen3 NVMe SSD is more than enough, and a Gen4 is "more than sufficient." The key is that, currently, games don't consistently saturate that massive bandwidth. Most accesses are small and random, where latency and IOPS performance matter more than raw sequential speed.
RTX IO, DirectStorage and the future of data access
The arrival of technologies like NVIDIA RTX IO and DirectStorage in DirectX 12 Ultimate has once again put SSDs in the spotlight, because they promise to further reduce loading times and free the CPU from much of the work it currently does with data decompression.
The approach is quite different from the current one. Instead of the CPU reading game data from the SSD, decompressing it, and gradually transferring it to the GPU, with RTX IO/DirectStorage the graphics card can request data directly from the SSD , using a buffer and dumping the information into its own VRAM. This requires minimal processor intervention.
On paper, this allows for much more direct access to game resources (textures, models, etc.) and reduces bottlenecks. The greater the SSD's bandwidth, the faster this data feed to the GPU can be, and it makes sense to think that a Gen4, or even a Gen5, could make a difference compared to a Gen3 in titles designed to take advantage of this technology.
However, there are several important nuances. For this to truly work, games must be specifically adapted, using the DirectStorage API and optimizing their data management. Simply having a fast SSD isn't enough. If the software isn't designed to take full advantage of it, the improvement will be limited. Furthermore, it's still a relatively new technology for PCs, so the wisest course of action is to wait for serious reviews and tests that measure its real-world impact with different types of SSDs.
Another factor to consider is the potential pressure on the market. If DirectStorage and RTX IO result in clearly visible performance improvements in many games, demand for Gen4 (or higher) NVMe SSDs could skyrocket, leading to shortages and price speculation . This has already been seen with graphics cards and even some CPUs in the past.
Where the difference between Gen3, Gen4 and Gen5 is noticeable
While the gap isn't that significant for gaming and general use, there are very clear scenarios where an NVMe Gen4 (and even Gen5) SSD does offer a tangible benefit. These include tasks such as 4K/8K video editing , working with massive files, multi-terabyte backups , and managing large databases.
In these situations, sustained transfers of massive files are performed. And that's where sequential speed matters. Copying 100 GB on a fast Gen4 SSD can take around 20 seconds. In contrast, on a powerful Gen5, that time is reduced by almost half. If you perform this type of operation once a month, it's not critical. But if you do it several times a day in a professional environment, the time savings are significant.
In server, AI, data science, and enterprise database environments, where millions of input/output operations occur per second, the increased bandwidth and slight latency improvement of Gen4 and Gen5 help reduce queues and improve system responsiveness. These are areas where every millisecond counts and where the additional hardware cost is easily justified. Furthermore, technologies like persistent memory are redefining how these challenges are addressed in professional installations.
Therefore, if your use is professional or semi-professional (video, high-volume photography, virtualization, heavy workloads), it makes much more sense to opt for a good NVMe Gen4 SSD , or even a Gen5 if your platform is compatible and your budget allows it.
What the benchmarks say: tests with Gen3 and Gen4 SSDs
To put all this into perspective, it's worth reviewing what has been seen in serious comparisons between PCIe 3.0 and 4.0 SSDs. In tests with drives like the Corsair Force MP600, GIGABYTE AORUS NVMe Gen4, and Sabrent Rocket 4.0 against an Intel Optane 905P and a Samsung 970 Pro, a system with a Ryzen 7 3700X and an ASRock X570 Steel Legend motherboard , running Windows 10, was used. These are serious comparisons and hardware analyses that help separate marketing hype from real-world performance.
In sequential read tests, the Gen4 drives with the Phison controller clearly outperform, achieving around 5.000 MB/s more, while the Gen3 drives lag behind at around 2.500-3.000 MB/s. These tests primarily serve as a benchmark for maximum theoretical performance , but reveal little about real-world use.
In sequential writes, the story repeats itself. The Sabrent Rocket 4.0 reaches its maximum write speed first and maintains it more stably, while the Corsair MP600 also approaches 4.000 MB/s but takes a little longer to stabilize. The GIGABYTE model, being of lower capacity, is penalized and doesn't exceed a stable 2.500 MB/s.
The PCIe 3.0 SSDs tested showed more inconsistent performance in sustained write speeds. The Intel Optane 905P stood out for maintaining a nearly flat rate of around 2.500 MB/s, while the Samsung 970 Pro started very strong but quickly lost performance , something that had also been observed in the read tests.
When you move on to more representative everyday use tests, such as IOmeter (random access) or PCMark 8 Storage, the picture changes considerably. In long work queues, the Sabrent Rocket 4.0 performs very well, but in single-queue scenarios (more similar to what a typical user does), the Intel Optane PCIe 3.0 outperforms all others by a clearly noticeable margin, thanks to being specifically designed for very low latencies.
Real-world usage benchmarks: Windows, office applications, and games
When tests focus on everyday tasks (booting Windows, opening Office, launching Photoshop, copying large and small files), the differences between Gen3 and Gen4 SSDs narrow considerably. In the PCMark 8 Storage test, Intel Optane once again dominates, thanks to its focus on productivity. However, the other SSDs, both Gen3 and Gen4, are very close in overall score , with no clear winner; the file system (NTFS) and its configuration also play a role.
Windows 10 boot times measured with various SSDs show that there are only a few seconds of difference between all the tested drives. Beyond a certain point, the motherboard's POST process, device initialization, and other factors independent of the SSD take over. Therefore, you can't significantly speed up the boot time even by installing a Gen5 SSD.
In large file transfers, it is noticeable that the faster models (for example, Intel Optane and some well-designed Gen4s) perform somewhat better, but we are still talking about seconds of difference in copies of several gigabytes, not dramatic leaps like those between a mechanical HDD and any SSD.
When copying many small files, the playing field becomes even more level, and latency and IOPS performance come into play. Here, both the Samsung 970 Pro (Gen3) and some Gen4 drives like the Corsair MP600 excel, demonstrating that PCIe generation isn't everything . The specific design of each drive plays a significant role.
And, returning to gaming, the tests with games show that the difference between the various SSDs tested, mixing Gen3 and Gen4, rarely exceeds 3 seconds in initial load time. That's practically imperceptible when actually gaming. And it certainly doesn't justify many users paying double for a latest-generation model just because it has a spectacular sequential read speed figure on the box.
Gen4 vs Gen5: the next twist
While we continue to debate whether Gen4 offers advantages over Gen3, the market is already pushing Gen5 NVMe PCIe SSDs . Once again, history repeats itself. Bandwidth per lane doubles, and theoretical figures skyrocket, this time reaching 9.000-14.000 MB/s sequential read speeds depending on the model.
On a technical level, Gen5 offers a total bandwidth of ~16 GB/s in x4 configuration, compared to ~8 GB/s for Gen4 and ~4 GB/s for Gen3. Latency also improves slightly, moving into the 50-70 µs range, although the gain here is much more modest than the jump in pure sequential speed.
In practice, most home users won't even max out a good Gen4 SSD with office tasks, browsing, streaming, photo editing, or gaming. For these workloads, Gen4 is already more than enough . The most crucial factor shifts from SSD speed to the processor, RAM, or GPU, depending on the specific needs.
Where Gen5 really starts to make sense is in those high-performance professional environments. We're talking about 8K video editing, handling massive scientific datasets, daily backups of several terabytes, content servers, or large-volume AI and database workloads. In these situations, the bandwidth increase and the ability to sustain enormous transfers for longer periods truly make a difference.
For now, Gen5 SSDs also have some additional drawbacks. They consume more power, run quite hot , and often require bulky heatsinks or even active fans. This doesn't always fit well in compact cases or quiet setups. Furthermore, their price remains higher, with differences ranging from 25% to 50% compared to a Gen4 drive of similar capacity.
