CrystalDiskMark reports less than impossible actual performance

[Dooley_labs]

So I acquired a few disks from a job I did a few days ago. Out of the few, one of them was an 80GB Hitachi 7200RPM drive. After zeroing it out, I ran a CrystalDiskMark test on it. Not surprisingly, it shows the drive maxes at 75MB/s, but I don't intend to keep anything of dire importance on it, so I copied a few ISOs to it. The second screenshot explains my confusion. It transferred in seconds from a HDD RAID. There's no explanation for this behavior, other than something called short stroke, but I've not taken any measures to set that up. The only other thing I can think is that something's amiss here; my main drive is an NVMe, but isn't involved in the transfer at all. Any ideas?

 

If anyone's wondering, the drive's formatted exFAT, though that's irrelevant.

 

Ignore the anime theme of CDM. It's a joke.

 

 

 

 

[NelizMastr]

It's a cached write operation coming from your RAID. That's why the speed is higher than you'd expect. It should dip down to the usual speeds once the buffers are emptied.

[samcool55]

Try to copy a file that's a few GB's, once the cache is filled up the transfer speed should take a dive and show the real speeds.

[Dooley_labs]

That's something else I forgot to mention; I've turned off the cache on these drives, specifically that option in Windows they tell you not to touch, though it's possible the RAID is doing something I'm unaware of. I'll get a few GB worth of files or one massive file and see what damage I can do. Keep in mind my ISO file transfered at 350MB/s without any dips in performance on the drive at all, but again that may be me misunderstanding the cache of these HDDs.