M11x Free Fall Sensor

I want to get a larger HDD for my M11x, but I'd like to get something that has movement protection. I've noticed a " FF_Protection" process running from Dell, which appears to control HDD activity based on data from an accelerometer somewhere. The question here is -- is it in the stock HDD, or is this on the motherboard?

I'd like to get a Seagate Momentus XT (SSD Hybrid), but it doesn't appear to have any free-fall protection. If it's a system-level thing, I'm wondering if it will still work out with the running FF_Protection process. Alternatively, I'm looking at Seagate's larger 7200RPM drives with G-Force protection, but then I wonder if the FF_Protection software could conflict with it. I've heard that you shouldn't get these HDDs for MacBooks because they already have a built-in accelerometer.

 

Most laptop drives have some sort of hardware level shock protection. If you're concerned about it look for the actual paperwork on the Seagate drive.

http://www.seagate.com/staticfiles/...book/momentus/XT (Anak 7200.1)/100610268a.pdf

Operating shock: 350Gs for 2ms. To be honest, I'd be worried more about the whole rest of the laptop. Also, if it isn't backed up then it isn't important.

 

Works fine with the XT.

 

Dell's free fall sensor is on the laptop itself. It is basically an accelerometer in the laptop chassis that detects a free fall drop. When it detects an acceleration that is significant enough to indicate a free fall, then it sends a command to the hard drive to prepare for impact. The drive responds by parking all of the hard drive heads, and reduce the risk of data loss when the impact occurs.

Old free fall sensors went through the SATA bus, which took a long time and could get delayed by any other I/O traffic on the SATA bus. Dell is using a direct data channel to the drive, which bypasses the SATA bus. End result is that the drive receives the signal much faster, and can respond much faster.

In order to use it, you must have BIOS support, OS support, and hard drive support. The M11x BIOS supports it. The OS supports it if you have the Free Fall Sensor driver installed. And the Seagate Momentus XT hard drive supports it. It is listed in the technical spec sheet.

 

Of course, this is the first thing to DISABLE if you install an SSD... otherwise, definitely ENABLE with an HDD... I believe there is a Dell Control Panel applet with the setting configuration.
- Kirk200

 

It does no harm if you have it enabled on an SSD, because it doesn't do anything. SSD's simply ignore whatever signal they get from the free fall sensor, since they are not susceptible to mechanical shock the way that HDD's are.

If anything, it might be best to simply uninstall the Free Fall Sensor software/drivers if you're using an SSD, just to free up some resources.

 

Good point Kent, I think I will try that. My experience (from a longer while ago), was on some Lenovo notebooks, which impacted user performance because their shock sensor also responded to "normal" vibration (like when it was on your lap), and for an SSD, it halted read/write to the drive, thinking it was helping prevent drive heads crashing... for the SSD it just stalled performance needlessly. I did disable the setting on the M11x R2, before even checking if this was a performance impact or not. If it's truly a free-fall sensor, and less sensitive than that old Lenovo approach, sounds like this is improved.
- Kirk200

 

Ah. That kind of free-fall sensor in the Lenovo was SATA-controller based, where the laptop + SATA controller would control the read/write signals to the hardware. It was definitely not a feature / command that was sent to the drive itself... because an SSD would simply ignore that command.

The benefit of doing it in the SATA controller is that it works with any hard drive - the drive does not specificially need to support this free fall command to use it. The drawback is that it is slower than Dell's implementation, because the signal needs to go through the SATA controller.

 

i had the same question... google it... landed right here...
I have this HDD (installed in a AW 11x first model launched) bought it for speed mainly : Seagate Momentus XT ST95005620AS and i did the following test, went to control panned, opened the FreeFall Data Protection software and simulated a free fall and guess what... the HDD made a strange high pitch sound and software displayed that an free fall event took place. Now the good thing is that free fall still works with this HDD, now the question is does the XT has the sensor or the laptop? (on the Seagate drive's specification page does not mention the existence of a free fall sensor on this model)

 

You don't read threads before you post, do you?

 

just loved your last post...it;s simply brilliant... it's so nice that u could call me an idiot in so many words... thank you!

Now in my defence :
Ok the laptop has a sensor on the motherboard, i get that, but WHY the original HDD (i had this model factory installed Seagate Momentus 7200.4 G-Force Protection ST9500420ASG) had ANOTHER sensor built in it?

So WHY installing an more expensive HDD with freefall sensor in it when u have an sensor ALREADY on the motherboard... this is where my confusion is coming from and hence my question that someone thought it was stupid...