11-06-2010 02:24 AM
Hybrid Hard Drives
Windows Vista and Windows Server 2008 also allow you to regulate the use of hybrid hard drives through group policy settings. In case you are not familiar with hybrid hard drives, they are hard drives that contain an extremely large cache made up of non-volatile flash memory. This cache is typically around 1 GB in size, and uses memory similar to that which is used in USB flash drives.
The reason behind this design is that the drive’s non-volatile cache is so large that the drive’s platters are almost never spinning, as opposed to a traditional hard drive in which the platters spin nearly all of the time. This decreases wear and tear on the drive, and also reduces the drive’s power consumption and the amount of heat that is given off by the drive. The biggest benefit though, is speed. A computer can read data from the hard drive’s non-volatile cache at a much faster rate than if data were being read from the disk platters.
Windows Vista and Windows Server 2008 offer four group policy settings that are aimed at helping you to control the way that Windows uses hybrid hard drives. Each of these four settings can be found at Computer Configuration | Administrative Templates | System | Disk NV Cache
The first setting is the Turn Off Boot and Resume Operations setting. The basic idea is that if you enable this policy setting, then Windows will not use the disk’s non-volatile cache to optimize the boot process. Otherwise, the system will use place files used during the boot sequence into the non-volatile cache, as a way of helping the system to boot more quickly.
Normally, if a computer is placed in hibernation, the data that is needed to resume operations is copied to the non-volatile cache. This helps a computer wake up from hibernation much more quickly. Enabling this group policy setting forces hibernation data to be written to the disk platters rather than to the non-volatile cache.
A second group policy setting related to hybrid hard drives is the Turn Off Cache Power Mode policy. Under normal circumstances, Windows aggressively attempts to reduce the system’s power consumption by spinning down the hard drive platters whenever possible. Although this technique does conserve power, and reduces heat, it can diminish performance as well. This is because Windows must spin the hard drive platters back up any time that it needs to read a file that is not cached in non-volatile memory.
The third group policy setting related to hybrid hard drives is the Turn Off Non Volatile Cache Feature setting. This is one of those group policy settings whose name can be a little bit misleading. If you look at the policy’s name, it appears as though the policy is used to completely disable the drive’s non volatile cache. There is a setting for disabling the drive’s non volatile cache, but this isn’t it.
The idea behind the Turn off Non Volatile Cache Feature setting is that if you enable this setting then Windows will act as if it does not support hybrid hard drives. This doesn’t mean that nothing will be cached, it simply means that the caching process will not be managed by Windows. In most cases your system will achieve far better performance if you allow Windows to manage the non volatile cache.
The last setting related to hybrid hard drives is the Turn Off Solid State Mode setting. When this group policy setting is enabled, Windows treats hybrid hard drives as normal hard drives. This means that the non volatile cache is completely disabled. As such, there is no power consumption speed related benefit associated with using the drive. The drive acts exactly like any other normal hard drive.
I have put a check mark in disabled for all of these, I also checked both boxes in device manager, hard drive, policies.
This is my only drive and contains my OS, windows 7 x64, perhaps windows isn`t managing properly.
09-10-2012 04:51 AM
Are You kidding me man!
With momentus xt you wan't even have nvcache settings in registry as this drives manage the solid state part by them selfs. It is only ment for drives with SLC not managed by drive firmware eg HItachi same rare hdds. This technology is named "VistareadyDrive". I'm not sure if it is still present in7.