Romex Software Forum

I own a Dell Precision T7600 with a Dell PERC H310 RAID controller. This is the RAID controller that does not have onboard RAM for caching. My two hard drives are not running RAID though. When I view Disk Drives under Device Manager in Windows 7, I see the following for both hard drives under Policies:

Enable write caching on the device (unchecked)
This device does not allow its write-caching setting to be changed

In the registry under \HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem, I see the following: NtfsMemoryUsage: 0

This disables Windows file system read and write caching. I am not sure if this is why I see the warning above stating the hard drives do not support write caching.

Will PrimoCache work on this system? I have been reluctant to try it out, since it is still in BETA. However, this will be good to know for when it is released.

I have a similar (albeit not identical) Dell system and have experienced no problems with PrimoCache. RAID is disabled. It has 4 mechanical drives; write caching is available and enabled on all. NtfsMemoryUsage registry key is also set to '0'; something else must be disabling write cache capability on your system. Win7 x32 (yes - 32 bit; necessary in client environment). I use 'invisible memory' for the cache - works great.

Thanks for the information. It looks like that \HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem\NtfsMemoryUsage registry value defaults to zero, so it will be zero on all systems unless it is changed using the fsutil command. I found info on it doing a Google search here: http://social.technet.microsoft.com/For ... nservergen. It seems this page has wrong information though. This does not disable the Windows file cache.

My workstation does not allow write caching to be turned on for any of my hard drives. When I try to turn it on, I get an error:

Windows could not change the write-caching setting for the device. Your device might not support this feature or changing the setting.

My guess is it is due to the drivers installed for the PERC H310 controller.

So this is a firmware-raid-controller which builds the RAID after BIOS initialisation, therefor the seperated drives report to the BIOS individually.

IMHO you need a real Hardware-Raid controller, which is able to report the array to the BIOS as a single "ahci-capable-drive". At this point the OS isn't even aware that this "drive" is a hardware-controlled RAID-array.

I do not recommend to try PrimoCache with Software- or Firmware-RAIDs at all... but i already do not recommend you any SW or FW-RAID at all. xD

Still like above said, there's no problem with just disabling RAID for this controller and use PrimoCache on each of the seperated drives.

So this is a firmware-raid-controller which builds the RAID after BIOS initialisation, therefor the seperated drives report to the BIOS individually.

IMHO you need a real Hardware-Raid controller, which is able to report the array to the BIOS as a single "ahci-capable-drive". At this point the OS isn't even aware that this "drive" is a hardware-controlled RAID-array.

I do not recommend to try PrimoCache with Software- or Firmware-RAIDs at all... but i already do not recommend you any SW or FW-RAID at all. xD

Still like above said, there's no problem with just disabling RAID for this controller and use PrimoCache on each of the seperated drives.

This is the RAID controller that does not have onboard RAM for caching.

The write-caching in windows-7-device-manager is not related to PrimoCache... it is activating the devices internal write-cache, in your case this is maintained by the controller, the only way windows could change that would be through the controller driver... but no, the device manager only applies standard AHCI-commands here... So also despite it is not using dedicated RAM, maybe you can share the controller some Sys-RAM. You can possibly change some of those settings in the BIOS or the FW-Controller Menu.

Also there is basically a difference in "having no RAID-array configured" and "having RAID disabled".

Make sure that "Sata Mode" in BIOS is set to "AHCI" not "RAID", otherwise "RAID is not disabled completely".

Chances high that OS will bluescreen when changing that...so first revert your Sata-Controller driver in device-manager to Microsoft Standard AHCI". That should do it, after that you should be able to access the "write-cache" settings and you can install AHCI-Chipset-Drivers (not RAID) finally.

I took a quick look at this in my BIOS setup. The settings in the main BIOS setup for the workstation do not apply, since the RAID controller has its own independent BIOS. The main BIOS is set for AHCI, but this only applies if the hard drives were connected directly on the mainboard (which they are not). The RAID controller's BIOS has a small number of options-- I can turn the controllers BIOS on or off (it won't boot at all with the BIOS turned off). That is basically it for settings.

I could try uninstalling the drivers for the RAID controller, but I am not going to bother at this point. I will stick with using a ramdrive only.