Question about keeping both epub AND mobi formats

[louwin]

I have about 3000 eBooks in epub AND mobi formats.

I hope to use an iPad 3 (when I can buy one!) as a reader so I have been informed, by kind suggestions from people here, that epub is the best format for iPad.

Is there any real, good reason to keep both formats?

I imagine I can select the books with both formats and delete the "mobi" ones?

In the off chance someone else wants the mobi versions, I assume Caliber can convert them "on the fly" to suit the output device?

Any reason for keeping multiple formats?

Some books have lit, prc, doc, epub AND mobi formats (heaven forbid)

[theducks]

Originally Posted by louwin

I have about 3000 eBooks in epub AND mobi formats.

I hope to use an iPad 3 (when I can buy one!) as a reader so I have been informed, by kind suggestions from people here, that epub is the best format for iPad.

Is there any real, good reason to keep both formats?

I imagine I can select the books with both formats and delete the "mobi" ones?

In the off chance someone else wants the mobi versions, I assume Caliber can convert them "on the fly" to suit the output device?

Any reason for keeping multiple formats?

Some books have lit, prc, doc, epub AND mobi formats (heaven forbid)

You might get a Kindle someday.
It is just cheap disk space

[louwin]

My daughter AND her husband have Kindles. I have my library on a portable external 1.5Tb drive and had expected my son-in-law to want access to it. I was offered a Kindle but thought I would wait for my iPad 3

Wouldn't Caliber convert the epubs on the fly when it sees the device is a Kindle?

It isn't so much the storage space, why keep something if it isn't necessary?

It is also unappealling to say "I have xxxx books but 5,000 are duplicates in other formats..."

When Caliber says the library contains "9155 books" does it include the same books in different formats?

[AnemicOak]

Originally Posted by louwin

When Caliber says the library contains "9155 books" does it include the same books in different formats?

9155 books would be 9155 titles it doesn't count each format separately in that total.

[theducks]

Originally Posted by louwin

My daughter AND her husband have Kindles. I have my library on a portable external 1.5Tb drive and had expected my son-in-law to want access to it. I was offered a Kindle but thought I would wait for my iPad 3

Wouldn't Caliber convert the epubs on the fly when it sees the device is a Kindle?

It isn't so much the storage space, why keep something if it isn't necessary?

It is also unappealling to say "I have xxxx books but 5,000 are duplicates in other formats..."

When Caliber says the library contains "9155 books" does it include the same books in different formats?

What a Fly it would be if you wanted one of those few books that took 24 HOURS to convert
True, that less than .0000001% (guesstimate ) take that long. but 10-20 minutes is not that uncommon for me.

[dwig]

Originally Posted by AnemicOak

9155 books would be 9155 titles it doesn't count each format separately in that total.

Actually, it means that there are 9155 entries in the book list. It is quite possible to have two entries with the same title.

If you were to import a library with multiple formats with calibre's "Automerge" turned off you will get separate entries for each format. If one title existed in three formats they would import as three separate books. If, on the other had, Automerge was enabled they would import as a single book entry containing three formats.

[louwin]

The library was given to me

I've spent weeks cleaning it up and adding to it. It was originally maintained under Unix(?) and has a LOT of long long files names that Windows does NOT like. Well, not in Calibre anyway. Funny things happen to these files under Calibre.

By limiting the formats I have to rescue I lessen my load.

The long filenames are not just a few characters over the 259(?) limit as can be explained by longer enveloping directory names etc. Filenames like 400-500 characters long

Some entries list every story in the collection in the filename

Happily duplication of entries is not one of the problems I have to clean up

So one of the libraries has 9155 books in it and there are four libraries

Anyway, I digress....

Wow! I didn't think conversions would take THAT long

I thought - a couple of seconds????

I have a Quad core i7 beast

[theducks]

Originally Posted by louwin

I thought - a couple of seconds????

I have a Quad core i7 beast

1 conversion: 1 core (you just get to do more at the same time )

[louwin]

Should that be - 1 conversion - 1 thread?

Quad core = 8 threads

[unboggling]

Originally Posted by louwin

I have about 3000 eBooks in epub AND mobi formats…. Is there any real, good reason to keep both formats?

Personally, I keep EPUBs only, not counting some PDF exceptions. I generate the MOBI on the fly when sending to device, followed by deleting the MOBI from the calibre library.

I don't do this to save disk space, but to save headaches and apply the KISS principle to avoid some problems: If there is more than one format for the book title, then which is the original format, or which is the best/most-cleaned-up format? When I keep only one EPUB format, or only a PDF format accompanied by an EPUB format, those problems don't exist. Also, there are better tools for cleaning up EPUB than for cleaning up MOBI.

Most of the long-duration conversions I've experienced apply to complex PDFs (often non-fiction, textbooks, computer-related) or old image-based PDFs. In these cases I keep the original PDF along with the mangled EPUB conversion, and if/when necessary read the PDF on iPad rather than PDF or MOBI on Kindle.

@louwin, in your case of obtaining someone else's library and not knowing which format (MOBI or EPUB or whatever) is the best most-cleaned-up format per Title, the only way to find out is to assess all of those formats for a given Title, one by one. Personally I would keep the best format, convert it to EPUB, clean it up if necessary, then discard all the other formats except PDFs in cases where the best formats are problem PDFs. All of this is very time-consuming and may not be worth the time and effort, depending on the quality of formats or metadata.

[louwin]

What a brilliant response.

[Crafter]

My calibre library is over 5,000 books and documents and I use both iBooks and the Kindle reading ap for iPad -- I'm constantly shifting between the two. Amazons free storage and ability to sync documents between devices is invaluable and Amazon will never support ePub in the foreseeable future. As others mentioned, storage is cheap and that whole library with both mobi and ePub is less than 7gb with metadata and covers all included. But, as good as the iPad 3 is for reading, my inexpensive Kindle e-ink gives my eyes a better longer read and syncs beautifully with me iPad -- so rather than delete one format over another, do consider keeping both major file types. Keep your options open.

[HarryT]

I would (and do) keep both formats. As has been said, disk space is cheap, and not all books convert cleanly from ePub to Mobi using default conversion options.

[louwin]

My complete library is about 110Gb as it stands with the duplicate formats....

[itimpi]

Originally Posted by louwin

My complete library is about 110Gb as it stands with the duplicate formats....

That is a gigantic size for the number of books you mentioned (3000) as most ebooks are under 1MB in size. It sounds as if you must have lots of books that are graphical in nature and thus are mainly images rather than being text based.

I have around 16K books in my library - and average about 4 formats per book and the library is still less than half the size of yours.