HTC has confirmed that, while the HTC Sensation has a 4GB ROM, only 1GB of that will be user-accessible. The dual-core smartphone reserves 3GB of the ROM for the Android install and the latest version of HTC Sense.
The news is likely to disappoint long-time Android users, who had hoped that more of the 4GB ROM would be available to install apps from the Android Market. While the OS now has support for Apps2SD, allowing software to be shifted from the phone's ROM to a memory card, not all apps support the system.
It remains to be seen how straightforward the Sensation's bootloader is for third-party hackers to tinker with the OS. Sense is looking increasingly bloated - though still fast-moving on the Sensation's 1.2GHz MSM 8260 processor - and stripping that out for a vanilla Gingerbread install would likely free up plenty more than 1GB of ROM.