Thank you very much pubidcam for getting back to me. Why I asked that question was for an obvious reason. That data transfer rate of 2MB/s is right on target for your case. Let me explain why. When you copy data from one drive to a different drive, simultaneous things are happening at one time. While the one drive is reading the data, the other drive is writing that same data. Therefore the speed will usually be as fast as the slowest hard drive in the system. Whether it be the drive that is reading, or the one that is writing, but in most cases hard drives writes are usually slower than their reading (45MB/s read average vs. say 30MB/s write average), but if you are transferring data from an older drive to a newer one, then obviously the read will be the limiting factor, as long as the read is less than the write speed of the newer drive.
Now in your case, what is happening is that it is not your system (motherboard, processor, memory, etc...) that is the limitation, but in fact the hard drive itself. As in the scenario above, that is the preferred situation of having to transfer data. In your situation, and for the most part with mechanical hard drives, when transferring data between partitions or places on that same hard drive, it will always be much slower than transferring to another drive.
Why? The answer is simple. As stated, when transferring data to a different drive simultaneous things happen at the same time. Where in a single hard drive scenario, the same hard drive is reading AND writing. This slows the hard drive down tremendously. Because as you should know, the modern and most common type of hard drive is mechanical, with metal platters inside the drive that read and write much like a CD does, only that in a hard drive data is written from the outside inward, where in a CD, it is the opposite. With this said, as you are copying (reading) data from the outer more parts of the platter (or vice versa, depending on where the data is located and how much of the drive space is used), at the same time the drive is also writing. This causes the hard drive to slow down a lot, because as the actuators (devices used in a hard drive to read and write) are at one part of the drive (assuming that you have the disk somewhat full and the data you are copying at the beginning of the hard drive), the actuators have to move away from the original spot on the platter of where it was reading the data to a more further spot to write and then back again to read. And it does this repeatedly, as you can imagine, this is not efficient or fluent. It's a start and stop process that happens repeatedly. And being such an old drive, it does not have NCQ or TCQ which would help in a scenario like this or a fragmented drive (where the data reading or writing is spread out and not next to each other). Where in a two drive situation, one drive is reading (constantly), and the other drive is writing (constantly), which makes it smoother and faster than a single drive transfer.
What plays into making your transfer speed slow is basically the rotational speed of the drive (RPM wise), internal drive cache (in your case a very small amount, 380KB), and platter size. So as you can see, the specs on the IBM drive are very low in terms of speed and up-to-date. It is no surprise that the IBM drive would get that slow of a speed. That is actually right around where you should be for that type of data transfer on that old of a drive.
I hope this answers your question and helps you, sorry that it is kind of long, I wanted to explain it as complete as I could in words and as simple as I could.