Metspitzer said:
I have wondered if you format a drive using the jumper to slow it
down, could you use the drive in another machine without the jumper?
SATA cable --------------------------------- Drive
150MB/sec or 300MB/sec 7200RPM, all the time.
The "force150" jumper has nothing to do with what is actually
stored on the drive. You can insert or remove the jumper and
all it does, is change the cable rate between the drive and
the motherboard. Normally, SATA drives negotiate the cable rate. It
is in cases where the negotiation fails, that the "force150" jumper
provides its main benefit (allowing the negotiation to arrive at
"150" as the setting to use). Some VIA chipset motherboards require
the user to insert the "force150" jumper, to get the drives to
be detected and be visible.
I've tested my system here, both with the "force150" jumper installed
and with it removed, and I can't tell the difference in terms of
performance. In Linux, I might note a message indicating what cable
rate is being used, but otherwise, I'd be oblivious as to what
rate it was running at.
The cable rate is more important, if you're using a SATA SSD with
200MB/sec+ transfer rates. But for the crappy rotating hard drives,
other performance issues swamp out what the cable is doing to you.
So it's not a big deal as far as I can see. I don't sit around
all day with a stop-watch checking these things. I don't notice
any "extra snappiness" when the "force150" jumper is removed.
Windows doesn't boot any faster. Firefox doesn't open any faster.
In the above example diagram, the disk spins at a constant 7200RPM,
whether the cable is 150MB/sec or 300MB/sec. The spindle doesn't
change speeds. The flying height requires reasonably controlled
conditions to work properly, so making big changes in the RPM
would be a mistake and could lead to a head crash. Some of the
latest drives have some means to dynamically monitor flying height,
so a drive like that may have options as to what it can safely
do. Older technology has no reason to be changing the RPM at all
and won't load the heads to the platter, until the RPM rate is
correct and constant.
Paul