The ESA SEU-Monitor, a 2 Gbit DDR2 SDRAM and a 100 V n-channel power MOSFET have been irradiated at GSI with ions of energies from 80 to 1500 MeV/n. The measured SEE sensitivities are compared to low energy data. The ESA SEU-Monitor and the DDR2 SDRAM showed only differences in the cross sections below the ionization threshold. Here the cross sections were lower for the high energy ions compared to the low energy ions. The power MOSFETs on the other hand showed a reduced safe operating area (SOA) for the high energy ions, although some experimental reasons other than the ion energy cannot be ruled out here.