I'm not familiar with the Fenix 5X but many devices, even not Garmin, need approximately 2X the size of a download for updates.  This is so the device remains operable (on the older software) in the case of an interrupted download.  I see that may be the case with the Fenix 5x as the download seem to indicate that the download is accomplished and then the updated software is installed.  From the manual, and I've changed the text in places to bold red for emphasis:

Updating the Software Using Garmin Express

Thank you for the reply...As to the suggestion lol... errrm express is always kept upto date.... As to the rest of the comment, PLEASE actually read what I put... 

rockncrag said:

PLEASE actually read what I put... 

Seems John From PA has answered some of your questions. Or do you mean this? 

rockncrag said:

Garmin get you damn act together please... 

NO he did not answer at all

Map is a map NOT a software update. 

map used to be SPLIT now is a single map which requires ALL other maps to be uninstalled before it will even download to the pc so it can than remove the original map off the watch..

I create my own maps routinely and whilst they may be  a newer version I DON'T need to uninstall maps I just OVERWRITE them.

Garmins answer.... oooooooooooo your watch hasn't enough room so we can't download too pc for later installation,   

you get what I mean yet?

But, as I tried to explain,  I don’t think GE overwrites maps, hence the reason it needs 22GB, 11 for the original and 11 for the newer version.  If overwriting was the process, and the device died or computer failed, say a power failure, some form of corrective action might have to be accomplished or you have a “brick”.

rockncrag

You need to read what Garmin say about Express. It says under specifications may require up to 20Gb of space.

Depending on the map you can install some to your PC then send to your device later, but note some map updates contain more than simply the map, so depending on the map and the device it is generally better to let Express install the map to your device. As for topo active moving to one large map most complaints come when Garmin are splitting previously one map into two, this is the first I've heard a complaint about them doing it the other way around!

LOL well I have over 100 gb spare space.... I removed every map of the femix5x leaving 14gb of space   map is 11.25gb   

thats what GE states...

so now what?????

I’m inclined to think that your computer has the 100GB of “spare space” but that has little to do with the space needed on the device for a map update.  As an example, like you, I have about 118 GB of free space on my PC, but if I tried to update my nuvi 2689 without the microSD memory card, the process would fail.  Whether that applies to a Fenix 5X I have no idea, I just offer that in explanation of why a certain amound of space may be required for a map update.

The issue is not the PC space though lol it is Express now saying I don't have enough space on my Watch for the map. even though there is enough space with spare left over(Fenix watches have only internal storage btw)..  This is a case of POORLY written software which Garmin KNOW about and them doing nothing too fix it...But thank you for your input.

You've clearly stated "LOL well I have over 100 gb spare space" so that must be PC space.  

I looked at the specs on the Fenix 5 and it has 12gb of internal storage.  The 5X Plus has 16 gb.  You might try removing old activity files to free up some space.  If you want to investigate that I suggest you review the thread at 5X memory full, and specifically the solution posted by "5058309" that is enclosed in a dark border near the bottom of page 1.