TTRAM is similar to conventional one-transistor, one-capacitor DRAM in concept, but eliminates the capacitor by relying on the floating body effect inherent in a silicon on insulator (SOI) manufacturing process. This effect causes capacitance to build up between the transistors and the underlying substrate, originally considered a nuisance but here used to replace a part outright. Since a transistor created using the SOI process is smaller than a capacitor, TTRAM offers somewhat higher densities than conventional DRAM. TTRAM is theoretically less expensive