Copy file from SSD to HDD, SSD shown as 100% busy – why?

Question

I was transferring some large files from my SSD to HDD, and looked at the Task Manager to see the usage of the drives. Here is a screenshot:

What this appears to show is my SSD working 95-100% all the time, and my HDD fluctuating between 50 and 100, which may mean that it is waiting on the SSD for the files to be read. Additionally, starting any programs on my SSD became very slow when the files were being moved. Is it possible that my SSD is actually slower then my HDD?

EDIT: I don't find the question that has been marked as duplicated from to be at all relevant. He is asking for a benchmarking tool, which I'm pretty sure goes under the "Opinion based" category anyway, and is completely different from my question which asks for reasons behind a bottleneck.As can be seen below it has attracted a completely different answer, to which I found to be useful.

Answer 1

Is it possible that my SSD is actually slower then my HDD?

Yes, that is possible. It is not the case that all SSDs are faster than all HDDs. There are very fast SSDs, and there are SSDs which are slow, even by rotating rust standards.

If that is the case in your situation os nothing we can answers based on just the information in your post, however consider these points:

1. SSDs are not nessecary fast on linear (large file) read or writes. They often are, but they shine in random access patterns. Copying a iso or other large file is something which fits perfectly with a clean HDD, but is not something where an SSD excels.
2. SSDs like deep queus for performance. If you set it to ancient IDE/legacy mode rather than AHCI you might get bad performace.
3. SLC SSDs are fast (and expensive). MLC is affordable and fast. TLC tends to be rather slow. My latest (BX200) SSD is TLC and performs worse than many a rotating HDDs. (on the plus side, it is silent and was very cheap).

So, answering on information provided: Yes, it is possible.