Random VS Sequential are different things. You are not guaranteed speed. The answer is not a one size fits all nor is it a sound byte. Class Sequential RW Random  RW Interface 10 Value 520K/320K 30K/10K Sata 20 Mainstream 500K/300K 80K/60K Sata 30 Performance 550K/350K 90K/75K Sata 40 Performance 1500K/350K 200K/80K PCI-E NVME 50 Performance 2100K/1200K 300K/100K PCI-E CARD X4   Sequential = Boot, hibernate,  daily power up and down Random = tasks such as file search:KIOPS Typical SATA 2 speed is 250K Typical SATA 3 speed is 500K The faster speeds are usually 2 NVME drives in parallel RAID 0 X16  PCI-E cards can Get 8000K sequential speed. [URL]  Sequential Read (MB/s) Sustained, 128KB                        8,150,000Sequential Write (MB/s) Sustained, 128KB                          4,800,000Random Read (IOPS) Sustained, 4KB QD64                          975,000Random Write (IOPS) Sustained, 4KB QD64                          132,000Random 70/30 R/W (IOPS) Sustained, 4KB QD64                  369,000  
Hey all, I was testing the NVMe that shipped with the pre-built that I ordered (I know, I know). It's a Samsung PM991a 256GB drive. The write speeds are terribly slow. According to the specs I've seen, the speeds should be up to 2200 MB/s read, and 1200 MB/s write. I'm getting less than 20% of that write speed. I've looked at firmware, and I seem to be on the most current one. I've tried ACHI and Raid.  I have checked with Dell tech support. They didn't do much beyond check for updates.  Pretty disappointed with this drive.  [IMAGE]
Samsung PM991a NVMe Slow Write Speeds