Quote from the review at Infosync World:
“The PEG-TH55 uses the same processor found in the UX50, dubbed the Sony Handheld Engine. It auto-throttles between 8 MHz and a modest 123 MHz, but provides more than enough power to drive normal applications at this resolution with music in the background. Web pages draw smoothly in the NetFront browser and generally there can be no performance complaints.
The TH55 offers 32 MB of user-accessible RAM, with a 32 MB ROM – a decent amount, but not top-of-the-range, and users will want to take advantage of the Memory Stick Pro slot. A 16 MB card came supplied with our test unit, but that may vary by market. ”