Hi. First, sorry for long post but I want to give you as much details as possible before asking my questions I've two 1 TB disk running in raid 1 (2 partitions, both mirrored) under Windows 7 Ultimate. Its clean install on new computer. System was installed on single disk and then both disk were converted to dynamic and mirror was added. It took about 4h 30m to synchronize array which means that sync speed was around 61 MB/s. Drive was already holding large amount of data when mirror was created. Yesterday I saw first BSOD after 1.5 year of using Windows 7 on various machines Computer usually shows login prompt in less than a minute, but booting to login prompt after BSOD took over 10 minutes due to really heavy disk activity. After logging in and launching disk manager (which took another 10 minutes) I saw that both mirrors were resyncing... in parallel. Computer was hardly usable. It was taking half a minute to just move mouse pointer to desired location not to mention at least 5-10 minutes waiting for web browser to launch. Because I needed my system usable in matter of minutes I did following: 1. Opened PC case, disconnected secondary SATA drive. 2. Booted to Windows, raid arrays got marked as degraded. 3. Shutdown PC, reconnected SATA drive. 4. Booted to Windows again, dropped mirroring. 5. Recreated mirroing, one partition at a time. And this is were my problems started. It took over 4 hours to resync system partiton (100 GB), and second partiton is still resyncing. Currently it is resynced in 35% after 14 hours which gives resync speed around 6 MB/sec. Its ten times slower than first array creation. So here are my questions: 1. Opening PC and disconnecting the drive isn't nice way to get system usable after each unclean system shutdown. Is it possible to force Windows to synchronize just one array at time? I couldn't find any setting for this and parallel raid synchronization is simply unacceptable. 2. What may have caused such slowdown in synchronization speed? 6 MB/sec isn't normal tranfer rate and its clearly system problem as it was over 60 MB/s during first mirror creation and no changes were made in hardware/software configuration.