Yes...they have different configurations that require a lot of ram. For example:
- Load the kick drum and pick your mallet
- Load your snare drum (top miced)
- Load your snare drum (bottom miced)
- Load the hi toms
- Load the low toms
- Load the cymbals
- Load the ambience mics
The newest patch on their download site now has a 'direct from disk' feature where it will load the beginning of the sample, and then load the rest when it gets used. This way, it won't load everything into memory...but if you want to load the ambient mics, then your looking at 750MB just for that. If you don't load the ambient mics, then you're using about 1.25GB.
However, they sound awesome so it's a non-issue for me.