32 vs. 64-bit Calibre

[NSILMike]

I just downloaded the Friday update as I always do. I run 64-bit Calibre, but I see the download page says "64bit calibre can be installed at the same time as 32bit calibre. The two calibre installs will use the same book library, plugins and settings."

Are there any advantages to using both? Why would someone do this...?

[BetterRed]

I sometimes install an earlier version in 32 bit if I want to see how something 'used to work', or when I'm communicating with someone who isn't using latest version.

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BR

[JimmXinu]

I've recently had at least one EpubSplit plugin user who couldn't split an especially large epub using 32 bit, but could with 64 bit.

I agree with BR, that the only reason I know to keep 32 bit is to have two different versions installed. But you can also do that with a portable install.

[theducks]

The only reason I can think of is you save $2
(2 bit is a USA slang for a 25cent piece)

Some folk have had Windows x64 balk, so they run 32 bit versions

But why have Both if 64 runs fine (and will handle bigger stuff)???

[BetterRed]

Originally Posted by JimmXinu

I've recently had at least one EpubSplit plugin user who couldn't split an especially large epub using 32 bit, but could with 64 bit.

For similar reasons (more addressable memory) conversion of big books is another major reason to use 64bit.

[HarryT]

Originally Posted by BetterRed

For similar reasons (more addressable memory) conversion of big books is another major reason to use 64bit.

It's only a benefit, though, if your PC has more than 4GB RAM, isn't it?

[BetterRed]

Originally Posted by HarryT

It's only a benefit, though, if your PC has more than 4GB RAM, isn't it?

True, you have to have the 'more addressable memory' - memory above 3.??GB is not accessible by 32bit programs, and 64bit programs wont install unless there's at least 4GB. Chickens and eggs, Catch22, two to tango and all that

BR

[dickloraine]

Maybe one of the reasons to both using the same config and libraries was just making it easy to switch to the 64bit version? So you could see if everything works with the comfort of knowing the "old" version was still there.

[Katsunami]

Originally Posted by HarryT

It's only a benefit, though, if your PC has more than 4GB RAM, isn't it?

Originally Posted by BetterRed

True, you have to have the 'more addressable memory' - memory above 3.??GB is not accessible by 32bit programs, and 64bit programs wont install unless there's at least 4GB. Chickens and eggs, Catch22, two to tango and all that

Even with less than 4GB, a 64-bit program can do things a 32-bit one can't; at least, it can on Windows. A comparison:

- 32-bit Windows can't address more than 3.2 GB of RAM (except if you have a version that has PAE: Physical Address Extension, but this is VERY slow).
- 32-bit programs under Windows (32 or 64-bit, doesn't matter) cannot use more than 2GB within one process.

Even if you only have 2GB of RAM, you could run a 64-bit version of Windows, and 64-bit Calibre, and convert a book that requires 8GB of RAM. It will be done using the swap-file. It'll be horribly slow, but it will work. 32-bit Calibre, on Windows 32-bit or Windows 64-bit won't be able to convert the book at all, because it'll hit the max of 2GB of memory per process.

Running 64-bit Calibre (on a 64-bit OS) doesn't gain you any speed, but it does gain you the capability to convert larger books, and convert more books at the same time, if you have enough processor cores.

I have never encountered a 64-bit program that will not install if you have less than 4 GB of RAM.

[JSWolf]

One of the computers we have has 3gigs of ram and is running a 64-bit Windows no problem. I plan to update it to Windows 10 soon and also up the ram to 4gigs.

[LAPIII]

is 64 bit slower than 32-bit? I only want to use Calibre to organize e-books with tags, so you won't be adding in the plug-ins.

[NSILMike]

If it is, it isn't noticeable to me (windows 7, 64-bit OS.)

[BetterRed]

Originally Posted by Advice Pro

is 64 bit slower than 32-bit? I only want to use Calibre to organize e-books with tags, so you won't be adding in the plug-ins.

The major difference between a 32bit and 64bit Windows is the amount of memory it can address. Conversions of large and complex books is the major feature of calibre that might require the extra memory available from 64bit.

If your Windows installation supports 64 bit programs there is no reason not to install 64 bit calibre.

BR

[Adoby]

Originally Posted by Advice Pro

is 64 bit slower than 32-bit? I only want to use Calibre to organize e-books with tags, so you won't be adding in the plug-ins.

It is both slower and faster. Like comparing a motorcycle with a truck. The motorcycle may be faster but the truck moves much more goods. Use 64 bit if at all possible.