PCIe 4.0 x4 NVMe SSD or PCIe 5.0 x4 NVMe SSD
Prefer the better-value PCIe 4.0 drive for normal desktop use. Choose PCIe 5.0 when measured work repeatedly transfers large sequential data and the platform can feed a Gen5 x4 slot without unwanted lane sharing.
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The comparison
What differs
3 of 6 fields differ. Both sides of every row come from a published manufacturer document, cited on the row itself, with what the difference does once the parts are in a case.
| Field | PCIe 4.0 x4 NVMe SSD | PCIe 5.0 x4 NVMe SSD | What the difference does |
|---|---|---|---|
| Host interface | PCIe 4.0 x4 at 16GT/s per lanepcisig.com, read 26 July 2026 | PCIe 5.0 x4 at 32GT/s per lanepcisig.com, read 26 July 2026 | PCIe 5.0 doubles link rate per lane, but only a Gen5-capable M.2 slot lets the newer drive negotiate that rate. |
| Sequential ceiling | About 8GB/s raw in one direction for an x4 link before protocol overheadpcisig.com, read 26 July 2026 | About 16GB/s raw in one direction for an x4 link before protocol overheadpcisig.com, read 26 July 2026 | The Gen5 ceiling benefits long sequential transfers that exceed Gen4, not small random requests, game logic, or work spent outside storage. |
| Thermal behavior | Drive-specific power and cooling requirementmicron.com, read 26 July 2026 | Drive-specific power and cooling requirement; higher interface capability does not set actual controller powerdownload.semiconductor.samsung.com, read 26 July 2026 | Check the selected drive's heat-sink guidance because neither the Gen4 nor Gen5 name supplies a safe operating temperature by itself. |
What is identical: 3 of 6 fields
This comparison comes from published specifications, not from testing. We do not test hardware, and we never present a judgment as though we had. No price appears here, because no retail price is published on this site yet.
In full
The comparison in detail
Prefer the better-value PCIe 4.0 drive for normal desktop use. Choose PCIe 5.0 when measured work repeatedly transfers large sequential data and the platform can feed a Gen5 x4 slot without unwanted lane sharing.
The interface doubles raw link rate, not every part of the SSD. Controller, NAND, cache, endurance, cooling, request size, and the time an application spends outside storage remain separate decisions.
Price boundary: our manufacturer specification list identifies current Gen4 and Gen5 models but records no reusable current price. Check the official Samsung 990 PRO Gen4 and Samsung 9100 PRO Gen5 pages, retrieved 26 July 2026, for a same-capacity live premium.
| Property | PCIe 4.0 x4 NVMe SSD | PCIe 5.0 x4 NVMe SSD | What it changes | Evidence |
|---|---|---|---|---|
| Host interface | PCIe 4.0 x4 at 16GT/s per lane | PCIe 5.0 x4 at 32GT/s per lane | PCIe 5.0 doubles link rate per lane, but only a Gen5-capable M.2 slot lets the newer drive negotiate that rate. | Gen4, Gen5, retrieved 26 July 2026 |
| Sequential ceiling | About 8GB/s raw in one direction for an x4 link before protocol overhead | About 16GB/s raw in one direction for an x4 link before protocol overhead | The Gen5 ceiling benefits long sequential transfers that exceed Gen4, not small random requests, game logic, or work spent outside storage. | Gen4, Gen5, retrieved 26 July 2026 |
| Mapping cache | Onboard DRAM or host-memory buffering depends on the SSD model | Onboard DRAM or host-memory buffering depends on the SSD model | PCIe generation does not reveal how an SSD stores its mapping tables, so compare the controller and cache design separately. | Gen4, Gen5, retrieved 26 July 2026 |
| NAND cell type | TLC or QLC depends on the SSD model | TLC or QLC depends on the SSD model | A Gen5 label does not guarantee TLC, and a Gen4 label does not imply QLC, so interface speed cannot substitute for NAND disclosure. | Gen4, Gen5, retrieved 26 July 2026 |
| Write endurance | Product-specific TBW rating | Product-specific TBW rating | PCIe 5.0 does not promise more warranted writes than PCIe 4.0, making each drive's TBW and warranty the buyer-facing endurance facts. | Gen4, Gen5, retrieved 26 July 2026 |
| Thermal behavior | Drive-specific power and cooling requirement | Drive-specific power and cooling requirement; higher interface capability does not set actual controller power | Check the selected drive's heat-sink guidance because neither the Gen4 nor Gen5 name supplies a safe operating temperature by itself. | Gen4, Gen5, retrieved 26 July 2026 |
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