Double Boot on Abit IP35-E board - what's the real harm to the system?

[GundamF91]

I'm trying to visualize what happens to hard disk drive when the double boot occurs. I'm thinking the hard disk drive or HDD is where the most impact can occur. I'm no expert so any help or discussions would be helpful.

1) First the powersupply turns on, which powers mainboard as well as the HDD. The HDD spindle and platter(s) start spinning. Actuator arms move out and ready to read/write. I don't know what the read-write heads are doing at this point. The head is definitely not writing, but it may have started reading something, may be the boot sector.

2) Then the system halts. IP35 maintains standby power (redlight) and uses it to reset the strap. We know for sure the HDD power is cut. This would be same as a general power loss/interruption. HDD platters would spin down but I'm not sure if the actuator arm would be able to go back to "landing zone".

3) Then double boot happens, basically power is back and HDD is powered up again. At that point, the actuator arm may be a potential issue, either go back to parked state, or swing out to read/write ready state. This may be not a preferred starting point for HDD mechanism. After that everything else goes back to normal. I think any potential double boot issue to HDD would be the impact to actuator arm.

To figure this out, we need to find out what's the normal procedure for HDD to power down? When Windows shut down, does HDD get a signal to tell it to power down and park the actuator arm so it's secure? Or does the system simply cut power and HDD just powers down on its own? Does PSU allow some type of power shutoff delay to let HDD go off?

Check out the Wikipedia info on what happens in power loss.

Landing zones and load/unload technology
Most HDDs prevent power interruptions from shutting the drive down with its heads landing in the data zone by either moving the heads to a landing zone or unloading (i.e., load/unload) the heads.

A landing zone is an area of the platter usually near its inner diameter (ID), where no data is stored. This area is called the Contact Start/Stop (CSS) zone. Disks are designed such that either a spring or, more recently, rotational inertia in the platters is used to park the heads in the case of unexpected power loss.

Spring tension from the head mounting constantly pushes the heads towards the platter. While the disk is spinning, the heads are supported by an air bearing and experience no physical contact or wear. In CSS drives the sliders carrying the head sensors (often also just called heads) are designed to survive a number of landings and takeoffs from the media surface, though wear and tear on these microscopic components eventually takes its toll. Most manufacturers design the sliders to survive 50,000 contact cycles before the chance of damage on startup rises above 50%. However, the decay rate is not linear: when a disk is younger and has had fewer start-stop cycles, it has a better chance of surviving the next startup than an older, higher-mileage disk (as the head literally drags along the disk's surface until the air bearing is established). For example, the Seagate Barracuda 7200.10 series of desktop hard disks are rated to 50,000 start-stop cycles.[23] This means that no failures attributed to the head-platter interface were seen before at least 50,000 start-stop cycles during testing.

Around 1995 IBM pioneered a technology where a landing zone on the disk is made by a precision laser process (Laser Zone Texture = LZT) producing an array of smooth nanometer-scale "bumps" in a landing zone, thus vastly improving stiction and wear performance. This technology is still largely in use today (2007), predominantly in desktop and enterprise (3.5 inch) drives. In general, CSS technology can be prone to increased stiction (the tendency for the heads to stick to the platter surface), e.g. as a consequence of increased humidity. Excessive stiction can cause physical damage to the platter and slider or spindle motor.

Load/Unload technology relies on the heads being lifted off the platters into a safe location, thus eliminating the risks of wear and stiction altogether. The first HDD RAMAC and most early disk drives used complex mechanisms to load and unload the heads. Modern HDDs use ramp loading, first introduced by Memorex in 1967[24], to load/unload onto plastic "ramps" near the outer disk edge.

All HDDs today still use one of these two technologies. Each has a list of advantages and drawbacks in terms of loss of storage area on the disk, relative difficulty of mechanical tolerance control, cost of implementation, etc.

Addressing shock robustness, IBM also created a technology for their ThinkPad line of laptop computers called the Active Protection System. When a sudden, sharp movement is detected by the built-in accelerometer in the Thinkpad, internal hard disk heads automatically unload themselves to reduce the risk of any potential data loss or scratch defects. Apple later also utilized this technology in their PowerBook, iBook, MacBook Pro, and MacBook line, known as the Sudden Motion Sensor. Toshiba has released similar technology in their laptops.

 

[21stHermit]

Is their a firmware fix for the double boot . OR . do I just live with the DOUBLE BOOT? :roll:

 

[brencat]

Don't know why this issue keeps coming up as the double boot has been resolved since Bios 13b/14. Unless you absolutely have to pull the power cord or turn off standby power on your surge protector, the system will not double boot with an updated bios unless you change FSB, multi, or RAM timing settings going forward.

 

[21stHermit]

That appears to answer the question for me. I live Off-the-Grid, leaving any ghost load on is an absolute no-no!!!

Every device I own save the refrig, well pump and furnace have an inline switch to disconnect them from any power unless I'm using them at that moment.

My solar panels develop about 3KWH per day . . . try living on that some day!!!

Thanks

 

[Heidfirst]

Originally posted by: 21stHermit
That appears to answer the question for me. I live Off-the-Grid, leaving any ghost load on is an absolute no-no!!!

pretty much any P35 mobo will double boot on the very first boot after power is applied following total disconnection as the chipset sets the strap.
the only 1 that I know shouldn't is the IP35 Pro because uGuru seems to take over/interfere with that function.