As a reply to lisbon2004 about starting a modems thread I think there is some of interest in that, and also for trying to clear some of the confusion up about all the different models and what is flashable with what and which speeds they support.
So the modems we've seen so far is:
- Qualcomm Gobi MDM9x25M / MDM9x35M (in all models with Snapdragon, N910F, N910G, N9106W, N9100 etc) - MDM9x25M is CAT4/LTE-A and MDM9x35 is CAT6/LTE-A
- Intel XMM7260 (in N910U) - CAT6/LTE-A
- Ericsson M7450 (in N910C) - CAT4/LTE-A
- Samsung Shannon 303 (in korean models N910S, N910K, N910L) - CAT6/LTE-A
Correct or complement the list if there is something inaccurate or missing in it. Maybe add firmware list for each later on?
Should note that CAT6 is only officially advertised on the Qualcomm Snapdragon model.
About the two different Gobi modems I think the China models N9100, N9106, N9108, N9109 use 9x25m and most of the other Qualcomm Snapdragon versions use 9x35m.
The Intel modem is also a category 6 modem and I'm not sure if something else makes it not fully support cat6. However Taiwanese Samsung site lists the N910U as CAT6 so I guess it has support.
Same with the Shannon models, they are advertised as LTE-A, however while trying to find out info about the Samsungs own Shannon modems it seems Shannon300 is CAT4/LTE-A and Shannon303 supposedly CAT6/LTE-A, atleast some lists it as that. Samsung korean site for Note 4 lists it as having theoretical support for up to 225Mbps which is in between CAT4 and CAT6 standard.
CAT4 modem = up to 150Mbps
CAT6 modem = up to 300Mbps
LTE-A was announced a few years back and provides faster and more stable network with higher capacity than regular LTE. Anything above CAT3 is basically LTE-A.