[CentOS] OT hard disk geometry

Sat Feb 8 14:01:07 UTC 2014
Darr247 <darr247 at gmail.com>

On 08 February 2014 @13:28 zulu, Timothy Murphy wrote:
> Miguel Medalha wrote:
>> The WD is a SATA3 drive (6gb/s). Are you sure that your motherboard
>> supports SATA3 drives? Maybe SOME ports support them while others do
>> not? If not, can you force the WD to operate in a lower mode? Some
>> drives can, either by hardware or software.
> Thank you very much for your lucid explanation,
> which has clarified the issue greatly in my mind.
> I was indeed completely ignorant of the basic facts about SATA drives,
> since in my (limited) experience they simply worked when installed.
> The two HP MicroServers I have are both N36L models, 3 years old.
> I had better check if these do support SATA3 drives.

Usually with WD SATA II and III drives, if you jumper pins 5 and 6 it 
forces them to the previous SATA mode for controllers that are not 

On SATA II (3 Gb/s) drives they called it OPT1; on SATA III (6 Gb/s) 
drives they call it PHY mode.
See the bottom of the page at 

Note those drawings show molex connectors which, as far as I'm aware of, 
they have never installed on SATA III drives, but that does indicate you 
start counting from the 'empty' space where molex connectors were 
mounted on EIDE, and on many SATA I (1.5 Gb/s) drives so people didn't 
have to buy adapters for their power supplies.