With new laptops coming out at a deep discount, many savvy computer users may be interested in taking advantage of such offers and then upgrading their laptop with a 3rd party solid state drive. The most common updates appear to be made through Crucial, OCZ, and Intel, all of whom make decent and well placed SSDs at what is slowly becoming an affordable price.
Modern AHCI controllers make use of a feature called TRIM. TRIM allows the operating system to inform the SSD that files are no longer needed on the drive and can be removed. To make a long story short, this helped solve a lot of problems with early SSDs and paved the way for better innovation.
If you are looking at new laptops recently, but are on a low budget, you may be in luck. Many new laptops are coming out with dedicated mobile video cards from NVIDA and ATI. They are also coming out with Sandy Bridge-based motherboards that have native USB3 ports and eSATA on-board. Here’s where things get tricky for upgraders:
First of all, you should know that with many Intel Sandy Bridge boards and later, you are going to have problems installing Windows 7 off USB. So you may want to think twice before you perform that clean install. This is because Windows 7 does not understand USB3 too well, and, at the time the OEM bits were shipped for the SP1 release and the original RTM, no one knew when USB3 was going to become available. You should be prepared to clean install Windows 7 from your DVD-ROM drive and install USB3 native drivers later.
Secondly, there is compelling evidence that there is a weird LPM issue with some SSDs, especially Crucial SATA-3 SSDs and LPM. LPM is basically a power saving feature for hard drives, but it can also cause some AHCI systems using Sandy Bridge-based systems and later motherboards to cause the SSD to go haywire and freeze. Fortunately, there is a way to solve the “system freeze” once Intel Rapid Storage Management (RST) is installed on your system.
First, check and see what is going on in your Event Viewer when the freeze takes place. If you are seeing something such as “The device, \Device\Ide\iaStor0, did not respond within the timeout period.”, you very likely want to deal with this problem using the fix detailed below.
Please remember, that while Intel RST was originally designed for RAID controllers, it is now used to exploit advanced features of Intel-based chipsets even on AHCI based systems. In other words, Intel RST is good to have for anyone using an Intel-based chipset.
Use the following registry edit to disable LPM if you are receiving an “iaStore” issue in Event Viewer, and an intermittent system freeze with your newly installed SSD:
Create a file called ssd-lpm-fix.reg using Notepad and enter the following data:
Run the .reg file to enter it into your registry and make the necessary modifications. You must have Intel RST installed for this to work.Code:Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\iaStor\Parameters\Port0] "LPM"=dword:00000000 "LPMDSTATE"=dword:00000000 "DIPM"=dword:00000000 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\iaStor\Parameters\Port1] "LPM"=dword:00000000 "LPMDSTATE"=dword:00000000 "DIPM"=dword:00000000 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\iaStor\Parameters\Port2] "LPM"=dword:00000000 "LPMDSTATE"=dword:00000000 "DIPM"=dword:00000000 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\iaStor\Parameters\Port3] "LPM"=dword:00000000 "LPMDSTATE"=dword:00000000 "DIPM"=dword:00000000 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\iaStor\Parameters\Port4] "LPM"=dword:00000000 "LPMDSTATE"=dword:00000000 "DIPM"=dword:00000000 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\iaStor\Parameters\Port5] "LPM"=dword:00000000 "LPMDSTATE"=dword:00000000 "DIPM"=dword:00000000
Also check out this guy's blog, who seems to know what he's talking about: Dell and Intel screw up big time -- iaStor and Windows Vista
Looks like this problem has been going on since Windows Vista, especially on Dell laptops, hard drives that may not fully support the LPM/LPD specification for Link-state Power Management, and other issues. One thing is for sure: If the crashing and freezing problems with your SSD or other type of hard drive go away after applying this patch, chances are you do not have a hardware problem, but, in fact, there is a problem with Intel RST itself or a flaw in the hardware implementation of Link-State Power Management over AHCI or RAID on your computer. If that's the case, there's probably nothing to worry about, for so long as the problem goes away. Since LPM is designed to save power, and since SSDs consume far less energy than a standard 2.5" hard drive, disabling LPM in the registry shouldn't create a battery issue.
Note: If you are not getting a "iaStore" error in your Windows Event Logs, you should be careful about making this change. Further, if you are not having any hard drive issues with intermittent freezing, etc. making this change will be mostly pointless. However, many users who have experienced intermittent hard drive freezes under AHCI and RAID have been able to solve the problem by disabling LPM in the registry using this option. A zip file of the .reg file is included as an attachment. Use at your own risk!