Black Drives Slower Than Blue is my disk test app wrong?

I have three of the Black type and two Blue type 2.5" drives. The Black drives are running significantly slower than the Blue ones based on the CrystalDisk 6.0.0 utility. I have:
2 WD7500BPKX-00HPJT0 Black
1 WD10JPLX-00MBPT0 Black

The Black drives are installed as files drives in my Windows 10 1803. The Blue are used as backups and are in removable caddies that go to the SATA6 system. All disks tested on the same motherboard SATA6 bus channel. Two were tested on different channels with no change in results.

The Black drives all are testing slower on all tests than the Blue by significant amounts. I then used True Image to write zeros across the disks then used Disk Management to format the drives (not checking the Quick format option). The results are the same. The Western Digital Dashboard tests all pass.

Is it correct to expect the Blacks to be Faster than the Blue drives?
Is CrystalDisk not working and/or is there a better/more trusted performance test utility?
Happy Trails

Hi Steve-L,

Benchmarking results are most often very system dependent and the results can vary from system to system. It would be best to refer factors explained in below article to check the performance and health of the drives.

Can you post a picture of the result ?
WD Black should give better performance on single work thread but newer model suffer some performance problems not recognized officially by WD.