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Hi I have run one long Solve, which took one hour, and seems to have found reasonable results, 6 solutions E1 for a system with 8 variables, two of them which I suspect to be simple. Unfortunately, running then

Save["E1.m", E1]
Print["Ed =", E1[[2]]]

has started a computation which takes more than 10 minutes, and cannot be aborted, so I had to quit the kernel. Guessing that the first operation is the offending one, is there a place in the documentation, or someone who knows how to choose between the commands Save, DumpSave, and Iconize?

And also if there exists a certain length limit for the result, after which all these commands fail, and saving becomes impossible? I'm asking this because I have run already into such problems, and I got the impression that such a limit exists.

florin
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    I would say Print might be more problematic. Just try Save or DumpSave without printing. – Domen Aug 11 '23 at 16:45
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    If part or all of your E1 includes := then asking MMA to give you E1 can make MMA redo all the calculations involved in that definition. When you DON'T have the result at risk try E1:=(Print["yes"];4); and then E1 again and again. Start MMA fresh and use = instead and repeat this. Next, MMA sometimes displays ... for huge results which can hide important stuff. Try InputForm[%] and click the output to select it and copy to clipboard and save clipboard to a text file. That MIGHT avoid recalculation, and save time. Next time past that file into MMA. Please be careful with this. – Bill Aug 11 '23 at 19:17
  • I had no :=. I have redone the calculation, using this time DumpSave. That took about 20 min. The size of the object is 18 GB, and I'm offered two further options I don't understand: Iconize and Store expression in notebook. My only concern is time, I need an option which will not take 20 min each time I touch this object – florin Aug 11 '23 at 20:09
  • I added a numeric condition because E1 was symbolic. Just gatting numeric values out of the symbolic 18 GB of assignments -> requires more than 5 minutes. How is this possible? – florin Aug 11 '23 at 20:26
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    Have a look at the task manager, drive activity. If for a 18 GB project your machine has less than 32 GB Ram, time is wasted in reading and writing to virtual memory on the disk. The speed depends on type of drive and in the case of an SSD on the interface and its writing speed. The deadly task is to read and write algebraic structures elementwise, very similar to an old lady searching for single pennies in her purse in the supermarket. – Roland F Aug 12 '23 at 06:30

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