Pratical difference between "load from memory" and "run from disk"


I'm using EasyBCD to setup my USB pen drive with some iso images. All works fine, but I don't know the pratical difference between "load from memory" "run from disk". So, in my EasyBCD menu I create things like:

Offline NT Password & Registry Editor (run from disk)
Offline NT Password & Registry Editor (load from memory)
MsDART (run from disk)
MsDART (load from memory)

My questions is, what the choice if...
(1) ... I want to preserve my pen drive (IE.: minimal read/writes);
(2) ... I want more speed;
(3) ... I want more compatibility (IE.: less problems when booting on different PCs/ISOs);

I know that maybe I cannot get all 3 above, but I don't know any answers above yet...

Thank you, and congratulations by the very nice software!
It's a tradeoff between the time it takes to preload vs the time it takes to load as you go.

If you try to add a large file (say, over 100mb) as load from ram, when you select the entry it'll freeze for a minute while it loads all 100mb into the memory. This is bad because, (a) you now have 100mb less memory, and (b) it'll take some time to do that; however it will subsequently "perform" faster.

So basically, use "load from ram" for files small enough that you don't notice a hang immediately after selecting the entry (say > 1 sec). Use load from disk otherwise.

Another thing to keep in mind is, if your ISO is 10mb, chances are all 10mb will be accessed multiple times during the usage of this ISO. But if the ISO is 100mb, chances are not all of it will be necessarily accessed. As such, it's *more* wear and tear to pre-load a large file, while it's *less* wear and tear to preload a smaller one.