I'm sure I'm not the only one wanting to increase the recording capacity of a PVR9150, so it may help if I relate my experiences. I have used three HDDs in the 9150. These were - 160GB Seagate (the original drive) 500GB Samsung HD502HJ 1TB Hitachi HDS721010CLA332 The Samsung drive works fine, the Hitachi drive did not. I think this is due to excessive loading by the drive on the +12v supply. The Samsung drive has a lower current requirement. The Samsung drive is currently (June 2011) listed by Amazon at about Â£30, and no doubt is available from other suppliers as well.