SSD

speed of a PCIe 4.0 NVMe SSD in a PCIe 3.0 Motherboard Slot?

bysize

Clone SSD on Linux

NOTE: both disk must be unmounted during the copy
Otherwise you may end up with error on partition (eg the /boot/efi)

$ lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
sda           8:0    0 931,5G  0 disk 
└─sda1        8:1    0 931,5G  0 part /media/yves/USB STICK
nvme0n1     259:0    0 476,9G  0 disk 
├─nvme0n1p1 259:1    0   100M  0 part /boot/efi
...
512110190592 bytes (512 GB, 477 GiB) copied, 1184,7 s, 432 MB/s
$ sudo dd if=/dev/nvme0n1 of=/dev/sda bs=64M status=progress
$ sync

Extend partition

Then gparted can be used to move & resize existing partition.

Convert MBR to GPT

an MBR-partitioned (standard) drive cannot be > 2To. You need GPT.

Non destructrive process

$ sudo gdisk /dev/sdX
# then press w to write converted partition
w

M2 SSD Benchmark & tests de performance

Top SSD

NVMe M.2 2280

Spare

SSD performance over USB

Notes - pcie gen 5.0 not recognized by a usb 3.1 nvme adapter? - this is expected…

Interface Real-world speed Relative speed vs PCIe 3.0
PCIe 3.0 x4 NVMe 3,000–3,500 MB/s 100%
USB 3.1 Gen 2 NVMe 700–1,050 MB/s 20–30%
USB 3.1 Gen 1 NVMe 350–500 MB/s 10–15%
USB 2.0 NVMe 30–40 MB/s 1%

PCI-Express Speeds

Version x1 Bandwidth x2 Bandwidth x4 Bandwidth x8 Bandwidth x16 Bandwidth
PCIe 1.0 250 MB/s 500 MB/s 750 MB/s 2 GB/s 4 GB/s
PCIe 2.0 500 MB/s 1000 MB/s 2 GB/s 4 GB/s 8 GB/s
PCIe 3.0 1 GB/s 2 GB/s 4 GB/s 8 GB/s 16 GB/s
PCIe 4.0 2 GB/s 4 GB/s 8 GB/s 16 GB/s 32 GB/s
PCIe 5.0 4 GB/s 8 GB/s 16 GB/s 32 GB/s 63 GB/s
PCIe 6.0 8 GB/s 15 GB/s 30 GB/s 61 GB/s 121 GB/s
PCIe 7.0 15 GB/s 30 GB/s 61 GB/s 121 GB/s 242 GB/s
Written on November 28, 2025, Last update on
pc-hardware disk storage