850 Evo 250gb only running @400mbps read and 400mbps write

[TraceDaBoss]

This was with the sequential test at 1gib on my 850 evo with 250 gigs of storage
This is abnormally low compared to the average of 500-540 for both. Why is this?
I have a maximus vii hero with a 4790k. Any ideas? Thanks

 

[tominsac]

I had a sata data cable issue once and it gave drive bad performance... worth a shot?

 

[saratj1]

Try the data cables with a metal clip that locks in may make it, what's your mobo, and double check which port your plugged into cause some motherboards share certain sata ports bandwidth with other things like USB or network , m2 . Then there's different sata controllers . Multiple sata link speeds and controllers on one motherboard isn't uncommon (ex marvel & Intel). Firmware updates to ssd , and sata controllers . And the drive being used while benchmarking, like benching your C: drive it's likely going to perform slower than a new empty drive that hasn't been running the windows while being benched. Many many things can effect the read write speed so many I couldn't name them all, here's some more, drive total usage , drive full or emptyness,
Msata 850 250gb 541mbs , 455mbs , then I have a ext. Raid box 3x1tb that benched 140's when empty and fresh, now half full runs 50's via USB 3.0. not sure why though.