Reason why AT&T's version of the HTC One X is not quad-core55
not compatible with LTE technology. So AT&T had a choice, they could stick with the HSPA+ connectivity that the international version uses, and keep the quad-core NVIDIA Tegra 3 under the hood, or they could go with LTE connectivity and use a different processor. AT&T, of course, went with the latter.
Despite having its hand forced by a technical issue, many might question AT&T's decision considering the paucity of LTE coverage that the mobile operator offers at the present time. Not much will change before the phone is launched in the States which is expected within the next 60 days. We are sure that there are some who feel let down and will now look elsewhere for their next upgrade. On the other hand, the specs are still beastly no matter how slice it. Looks like AT&T customers will have as tough a decision to make as their carrier had.