System is Win 8 on a core i7-3820. TRIM command was not working on a previous SSD installed in system, and computer eventually ground to a halt. Replaced that SSD with a new Samsung 840 256 GB SSD. TRIM not working on it either. Samsung tech support says that the reason TRIM not working is that Windows chose a SCSI driver instead of MSAHCI.sys driver when O/S was installed, and that I should get Microsoft to tell me how to change the drivers. However, if Windows made a mistake in choosing the driver for the SSD, it made the same mistake for all the non-USB drives; here are the registry entries:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\disk\Enum]
"0"="SCSI\\Disk&Ven_Hitachi&Prod_HDS723020BLA642\\5&2e959a15&0&000000"
"1"="SCSI\\Disk&Ven_Hitachi&Prod_HDS5C3030ALA630\\5&9bcdacb&0&000000"
"2"="SCSI\\Disk&Ven_ATA&Prod_Samsung_SSD_840\\4&a8975d2&0&000000"
"3"="SCSI\\Disk&Ven_ATA&Prod_Hitachi_HDP72505\\4&a8975d2&0&020000"
"4"="SCSI\\Disk&Ven_ATA&Prod_Hitachi_HDS72101\\4&a8975d2&0&030000"
"5"="SCSI\\Disk&Ven_ATA&Prod_Hitachi_HDS72101\\4&a8975d2&0&040000"
"6"="USBSTOR\\Disk&Ven_Seagate&Prod_Backup+_Desk&Rev_D802\\NA5J9FND&0"
"7"="USBSTOR\\Disk&Ven_Hitachi&Prod_HDS721010CLA332&Rev_\\FFFACFF0FD000000FF2911FF0FAEDA&0"
"8"="USBSTOR\\Disk&Ven_Seagate&Prod_GoFlex_Desk&Rev_0D1C\\NA0M3BG4&0"
TRIM has to work; OW writes become intolerably slow and system crashes. What can I do to make system use MSAHCI.sys, if indeed you agree that is the problem?
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