Help customize Calibre Portable for SSD

[pleiadesc]

Hi,

I use Calibre Portable in windows, I would like to use my SSD to speed up calibre but I have a small SSD, I would like to move application and metadata into the SSD and leave the books on the HDD

I found a bat file inside a folder in L:\Calibre Portable\Calibre\app\resources\ made by itimpi. Is this still recommended to use? It has a different folder structure than the Calibre Portable

I would like to retain the folder structure so I can just overwrite it with a new version of Calibre.

The easiest way I can think of is to copy everything into the SSD and symlink the Calibre Library which contains the book

The problem is the metadata.db and a json file is inside the Calibre Library folder.

Can i change the metadata.db location by adding a command to the launcher similar to the batch file?

Thank you!

[BetterRed]

Originally Posted by pleiadesc

Hi,

I use Calibre Portable in windows, I would like to use my SSD to speed up calibre but I have a small SSD, I would like to move application and metadata into the SSD and leave the books on the HDD

I found a bat file inside a folder in L:\Calibre Portable\Calibre\app\resources\ made by itimpi. Is this still recommended to use? It has a different folder structure than the Calibre Portable

I would like to retain the folder structure so I can just overwrite it with a new version of Calibre.

The easiest way I can think of is to copy everything into the SSD and symlink the Calibre Library which contains the book

The problem is the metadata.db and a json file is inside the Calibre Library folder.

Can i change the metadata.db location by adding a command to the launcher similar to the batch file?

Thank you!

Putting symlink to an hdd resident library into the ssd resident Calibre Portable folder should be OK, but I am not sure if you can use the CALIBRE_OVERRIDE_DATABASE_PATH environment variable in Portable to 'redirect' the database location - I have a feeling you cannot.

If your SSD is an internal drive what's the point of installing Portable on it?

FWIW: I moved a 120K book library with a 300MB metadata.db from a WD Caviar Black HDD to my Samsung 500GB nVMe M2 SSD. The performance difference was negligible - start up times went from 8s to 5s, switching VM Views, VLs, bulk metadata edits were all much the same - after a couple of days i put it back on the HDD. Why would this be so - because for most operations calibre uses in in-memory copy of the database.

BR

[pleiadesc]

Thank you BetterRed for the real-world usage test, I like the portable version because I like to keep all the configuration files in a single folder. I won't think about this too much.

[BetterRed]

Originally Posted by pleiadesc

Thank you BetterRed for the real-world usage test, I like the portable version because I like to keep all the configuration files in a single folder. I won't think about this too much.

By default calibre keeps its global configuration data (preference settings, plugins, configuration overrides etc) in the %APPDATA%/calibre folder. The CALIBRE_CONFIG_DIRECTORY Environment variable is available if you want to relocate it elsewhere. Library specific configuration data is kept in the library databases.

AFAIK the only calibre related entries in the Windows registry are those put there by the so-called Trusted Installer.

BR

[pleiadesc]

Thank you again for the Environment variable, I don't mind the windows registry entries, I will customize itimpi's batch file and change the folder structure similar to the calibre portable.

[BetterRed]

I have to say this - in my opinion you may be wasting your time. In times foregone, getting the metadata.db onto a faster device may have had some mileage, but I'm not sure that's true today.

When I got a Samsung 500GB Nvme M.2 system drive in In Q3 2017, I moved my Books library (120,000+ books) onto it just see what difference it made. The start up times dropped from 7-10 secs to 3-5 secs - nothing else changed, sorting and searching were just as fast as they when the library was on a 2 TB WD Caviar Black drive, adding books, conversions etc were about the same (Temp is on the SSD).

So I moved the library back to the HDD. i don't like having data on the same drive as the OS - and at the time I wasn't inclined to partition the SSD for an extra 5 secs once or twice a day

BR

[mbovenka]

Originally Posted by BetterRed

I have to say this - in my opinion you may be wasting your time. In times foregone, getting the metadata.db onto a faster device may have had some mileage, but I'm not sure that's true today.

I pretty much agree.

I recently moved from a dedicated 5400RPM HD to a SATAIII SSD (running at SATAII speeds, though; the second SATA port in my laptop turns out to be SATAII only) and my startup time is a few seconds faster (pretty much the difference in throughput of the two drives in loading the metadata DB).

Adding books is a bit faster, though, as are things like embedding metadata. Bulk saving of OPF files (calibredb backup_metadata) is a *lot* faster. That's the SSD handling small files a lot better than spinning metal. Conversions are a wash, probably because my system disk (and thus my temp dir) already was an SSD.

In all, the gains aren't as great as I'd hoped.

[kovidgoyal]

all read only operations owrk on a pure in-memory representation of the db, so are unaffected by the speed of the disk on which the db rsides.

[pleiadesc]

@BetterRed

Thank you for the advice, I like to test it out myself, so far the startup times are a little faster but overall speed is the same. what I learned from testing this is that I can separate the library from the applications which is very cool.

@mbovenka

Did you separate the library and the applications?

@kovidgoyal

Thank you for your insight, How about the write operations? does the SSD have any effects?

[kovidgoyal]

yes, ssd will help with initial load and write operations, but write operations are typically a very small fraction of total workload.

[mbovenka]

Originally Posted by pleiadesc

@mbovenka

Did you separate the library and the applications?

Yes, the library is on a separate SSD from the application.

[theducks]

Many of my Libraries are on different LOCAL drives.
My 'Main' is on a 'Caviar Black'. It doesn't help, when the activity light appears solid. The systems data bus is saturated (I rarely use swap. 8G of RAM)

[ilovejedd]

Originally Posted by theducks

Many of my Libraries are on different LOCAL drives.
My 'Main' is on a 'Caviar Black'. It doesn't help, when the activity light appears solid. The systems data bus is saturated (I rarely use swap. 8G of RAM)

It really depends on what you're doing. I actually have run some batch import tests and there was a huge speed up keeping the Calibre library on a separate drive from the OS when using mechanical disks.

https://www.mobileread.com/forums/sh...8&postcount=17

I'm happy to keep my full Calibre libraries on SSD. I also use one of my older SSDs for quick copies/backups. I do backup to HDD, but that's more like a scheduled overnight task or when I'm not pressed for time. Not a need to make a copy and get out in 5 minutes kinda thing.

[pleiadesc]

Originally Posted by kovidgoyal

yes, ssd will help with initial load and write operations, but write operations are typically a very small fraction of total workload.

for sharing

[pleiadesc]

Originally Posted by mbovenka

Yes, the library is on a separate SSD from the application.

, I like the idea of separating the library and application.