I have looked at the release notes of the current Mathcad 15 M050 (see attached) and could not find any note that a memory leak would have been fixed, but there are some other bug fixes after M030 which may be of interest:
Without seeing your Mathcad worksheet I have to guess. But, as you say, this has come up before, many times, so it's an educated guess.
How can such a small amount of data lead to such huge memory requirements? The answer is probably that you are creating many copies of the data in the worksheet. Take this simple example, where A is your data:
B, C, and D are all copies of your data, and all are stored internally, because Mathcad has to be able to display them at any time. You might think that overwriting A is a solution:
It's not. Each new A is still held internally in memory. The second A can't overwrite the first A because Mathcad has to be able to display both, depending on where in the worksheet you put an evaluation.
Creating a long series of static calculations is a bad way of doing things in Mathcad. There are many reasons why that is true, and this is one of them (especially when it comes to data analysis).
Instead, define a function:
This takes negligible memory, and has the advantage of being reusable throughout the worksheet.
Then you can do
All the intermediate results, which you likely didn't need to look at anyway, are gone, along with the memory required to store them.
Vladimir, do you also know where you can download mathcad 15M050? The link goes to matcad 15M045.
I don't think there is any public place where you can download M050. That was the first bugfix after PTC switched to subscription only, so I think is it available only on a subscription license. I am working under the assumption that MC15 045 is the last version of Mathcad I will ever have (not including some versions of Prime that I never use)