Thread: Calibre Speedup
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Old 10-27-2012, 05:48 AM   #41
itimpi
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Quote:
Originally Posted by cybmole View Post
just indicating that you all are wasting hours/days failing to save even seconds:-)

see previous post conclusion:
"Surprisingly putting calibre conversion temp files on ramdisk results in the same conversion times as with no ramdisk."
That is true in the case of Calibre as it is CPU bound during conversion and does most of the work in RAM (which is why converting large books can be RAM intensive.

However it is not good as a generalization. If a program creates lots of temporary files then using RAM for temporary files can make a bid difference. An example of this that I am aware of is calibre2opds. That creates LOTS of temporary files while running and using a RAM disk can easily give something like a 30% improvement in run time on.

In fact the main use that I had for the CALIBRE_TEMP_DIR setting was the fact that Calibre was prone to leaving the temp files around when it had finished rather than removing them. Giving Calibre its own private temp folder mad it easy to develop a batch file for launching Calibre that tidied up any files left from previous runs.

Quote:
don't you get that if having temp files in RAM was such a smart move it would be in Windows alreay. Microsoft have good reason for not doing that which google will explain to you if interested.
Which is probably why Microsoft are now adding features to Windows that support just this mode of working I suppose!

It is only recently that RAM has become cheap enough that the average user was not better using additional RAM to reduce Windows use of a swap file. However now RAM is cheap enough that it is quite feasible to have more than enough RAM to run without a swap file and still have enough free for uses such as temporary files in RAM. I found that switching off the Windows swap file and using a RAM disk for temporary files made my Windows system much more responsive. I did have 16GB of RAM available in this case which was why I thought it was worth experimenting.

Quote:
now I return to to how many angels can I balance on this pin / how many nanoseconds can I shave from this process.
have a nice day & don't waste too much time composing a retort - you may need those seconds
You seem to have lost site of a secondary objective to this activity. That is if you have a SSD then having the temp files in RAM rather than on the SSD can reduce wear on the SSD. For many who are light users of their machines this will not matter as the SSD will outlast their PC, but if you are a heavy user it can definitely become a factor. For this use knowing how to use RAM for temporary files has a wider benefit than just Calibre.

Then there is simply the interest factor in knowing how to do something like this. It might not be cost-effective but it can still be stimulating to do this sort of investigation

Last edited by itimpi; 10-27-2012 at 05:51 AM.
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