09-26-2025, 12:43 PM
Great question, and one that comes up a lot when people see those big 3,500 MB/s numbers in SSD marketing. In practice, you will not see those speeds on a NAS the way you would in a local PC benchmark.
A few key points:
1. Network bottleneck – Even a 10GbE network link caps out at about 1,100 MB/s real throughput, so that’s your ceiling unless you’re running multiple aggregated 10GbE links or 25/40GbE hardware. On a 2.5GbE or 1GbE NAS, the maximum you’ll see is ~280 MB/s or ~110 MB/s, regardless of whether you use NVMe.
2. NAS motherboard and PCIe lanes – Many NAS models don’t give NVMe drives the full PCIe 3.0 x4 bandwidth. Often, the slot is limited to PCIe 3.0 x2 or even x1, which reduces maximum speed to around 1,600 MB/s or 800 MB/s before other overheads.
3. RAID and firmware overhead – If you run NVMe in RAID or as a cache, the CPU and storage controller add latency. Cache is most useful for small random reads/writes (like databases or lots of small files) rather than large sequential transfers. For video editing or big file moves, the benefit is limited.
4. Real-world results – In most NAS setups, even high-end models, you’ll realistically see 800–1,200 MB/s from NVMe in best conditions, which is about a third of the advertised peak. That’s already very good, but it’s not “3,500 MB/s” as the packaging might suggest.
A few key points:
1. Network bottleneck – Even a 10GbE network link caps out at about 1,100 MB/s real throughput, so that’s your ceiling unless you’re running multiple aggregated 10GbE links or 25/40GbE hardware. On a 2.5GbE or 1GbE NAS, the maximum you’ll see is ~280 MB/s or ~110 MB/s, regardless of whether you use NVMe.
2. NAS motherboard and PCIe lanes – Many NAS models don’t give NVMe drives the full PCIe 3.0 x4 bandwidth. Often, the slot is limited to PCIe 3.0 x2 or even x1, which reduces maximum speed to around 1,600 MB/s or 800 MB/s before other overheads.
3. RAID and firmware overhead – If you run NVMe in RAID or as a cache, the CPU and storage controller add latency. Cache is most useful for small random reads/writes (like databases or lots of small files) rather than large sequential transfers. For video editing or big file moves, the benefit is limited.
4. Real-world results – In most NAS setups, even high-end models, you’ll realistically see 800–1,200 MB/s from NVMe in best conditions, which is about a third of the advertised peak. That’s already very good, but it’s not “3,500 MB/s” as the packaging might suggest.