I've always struggled to grasp quite exactly what it is that determines read/write transfer directions on drives as well as the correlation between benchmarks on hard disks and real world usage. The first question is whether or not the drive your sending a file to is being written to, or is reading the data that's coming in. Are they the same operation or treated differently? The speed being reported, is this the drive that's sending the file or the one receiving it? For the benchmarks, most of them show peak burst but not sustainable throughput and similarly so do reviews. Yet when you actually move anything but a single compressed file, you get speeds that are half what testing programs or reviews would suggest. Why is it that reviewers never seem to just transfer random files manually and treat that as 'real world?' Lastly, as per below picture, this is how my drives settled after putting in a second SSD and installing Windows onto it. Unnamed EFI partition: SSD Disk 0 C: - Windows installation permanent SSD Disk 0 F: - Old Windows installation/temporary storage SSD Disk 1 D: - Storage HDD Disk 2 E: - 'System Reserved' EFI partition with data on it SSD Disk 1 For the unnamed EFI partition, it's great that it's the first partition on the disk however it's empty? What's the point of it then? Is E: necessary? Why is the EFI partition from Disk 1 listed as "Active and primary?" Conversely, when I load up the old SSD, there's no EFI partitions for either disk showing in Explorer. I am feeling OCD a bit on this and would like to clean it up so that everything is as should be.