Standard for PCIe 2.0 x1 : 500MB/s, a little bit slower as SATA 6Gb/s, but PCIe 2.0 x4 : 2000MB/s. If support PCIe 3.0, standard for PCIe 3.0 x1 : 984.6MB/s, then PCIe 3.0 x4 should be 3938.4MB/s.
You're right! But the Gemini Lake doesn't have PCIe Gen 3 lanes! I think Intel purposely doing it to classify between high-end & mainstream platforms.
I would like to share more result or compare with other SSD, for example, I find the result on Samsung 860 EVO (SATA 6.0) by my old macbook pro, cpu is i5-2435M, ram is DDR3 8GB, then GLK-UC2X with Crucial P1 M.2 500GB is more comfort to use...
4K random read/write speeds look a lot faster on your GLK-UC2X, so you should feel more responsive inside of Windows.
I'm going to test more result about M.2 if running PCIe 3.0 x4, the result is big different on Seq read/write... random read/write is not big (compare with GLK-UC2X by PCIe 2.0 x1)
OMG... I checked my windows in macbook is ATA mode (AHCI disabled), now I switch it back AHCI, the result on my SAMSUNG 860 EVO is full speed now. After that, I'm going to review my experience on HDD/SSD, I remember that my 1st hdd is talking ATA66, ATA100, ATA133, SATA1 (around 150), SATA2 (around 300), SATA3 (around 600), now SSD by NVMe is talking PCIe 1.0, 2.0, 3.0 (with x1, x2, x4)
WD Blue 1TB, both read/write speeds are working exactly as advertised! 2TB is also available but it costs too much so we didn't buy it~ amazon.com/Blue-NAND-1TB-SSD-WDS100T2B0B/dp/B073SB2MXT/