With each page request, Silk dynamically determines a division of labor between the mobile hardware and Amazon EC2 (i.e. which browser sub-components run where) that takes into consideration factors like network conditions, page complexity and the location of any cached content.
Series I bonds consist of two components: a fixed interest rate return and an adjustable inflation-linked return, making them somewhat similar to TIPS. The fixed rate never changes, but the inflation return rate is adjusted every six months and can also be negative (which of course brings your total return down).