[en] Fermilab plans to deliver 5-15 fb^-1 of integrated luminosity to the CDF and D0 experiments. The current inner silicon detectors at CDF (SVXIIa and L00) will not tolerate the radiation dose associated with high-luminosity running and will need to be replaced. A new readout chip (SVX4) has been designed in radiation-hard 0.25 μm, CMOS technology. Single-sided sensors are arranged in a compact structure, called a stave, with integrated readout and cooling systems. This paper describes the general design of the Run IIb system, testing results of prototype electrical components (staves), and prototype silicon sensor performance before and after irradiation