Originally Posted by ljbad4life
The tegra 3 is supposedly incompatable with LTE radios, if you take a look at the HTC one x. The One X uses the Tegra 3 overseas (where LTE isn't big), but in the USA all LTE equipped One X derived phones are not Tegra 3 devices (including sprint's EVO 4g LTE)
I remember that they said the Tegra 2 was incompatible with 4g at all, but we have the photon. I just think Nvidia just hasn't optimized the tegra 3 for LTE. All of the LTE networks work on different bands, so I can't see how it could interfer with both 700 (upper and lower bands), 800, and 1900.
The Tegras are not incompatible with LTE radios. They don't integrate the radios like the S4 does (yet) which makes a device with the Tegra 3 SoC and the separate 2G/3G/4G radios more expensive to build and maintenance (OS updates) trickier. The battery life also suffers a bit compared to an integrated solution and the main board is bigger.
nVidia bought Icera last year and they'll be integrating the Icera softmodem into future Tegras in order to better compete at the phone level (which will actually make the Tegra very versatile). They couldn't get Icera tech integrated fast enough for Tegra 3 (since the Tegra 3 was already sampling before they bought Icera).
The S4 has fewer faster CPU cores and integrated radios but a slower GPU. The Tegra 3 is a better non-phone solution which is more power efficient in a wifi-only loadout. Hardcore mobile gamers aside, most users won't notice a difference.
Bottom line: It's business, not a hardware limitation.