We are now designing new type of storage system for the recording of VLBI data, which is based on PCI Express interface. In this type of system, data is transferred from data server to storage directly without data conversion or memory buffering between each system. In this paper, we evaluate I/O performance of PCI Express based storage by writing massive streams from memory buffer to storage, and compared the results with that of other storage such as Mark6 and Lustre based general storages.