HDD understanding :)

[tuRnitUpsuM]

ready !


here we go...


... PATA ( Parallel ATA ) is an IDE ( Integrated Drive Electronics) drive much like SATA. It is also known as EIDE (Enhanced IDE). Parallel ATA ( PATA) works on the idea of sending data through the computer on many channels, connected by 40 pins ( wire-wise as much as 80... the extra 40 used as grounding to reduce background noise) but still on a 40 pin connector. These types of drives have been used for awhile and has a maximum throughput of 133 MB/s. But almost never achieve that even in a RAID ( Redundant Array of Independant Discs ) set-up. The cache can't predict your next request as accurately as theory suggests. Through-put is closer to 60 MB/s. RAID improves this tremendously though closer to maximum but not quite.

spindle speeds between 4200 - 7200rpm i believe

...SATA ( Serial ATA ) is a newer technology opposed to PATA. It uses a much smaller wire to achieve a much higher through-put. A single channel in fact kinda like putting your thumb over a faucet. Allowing a jet of data through. i remember it being described as a hose effect in a garden/ yard ( steady flow of water becomes a very fast stream). Through-put of SATA are higher than PATA drives.

spindle speeds between 5400 - 10000 i believe

< new OSes acknowledge both PATA and SATA identically...as far as i know)

...SCSI (Small Computer Systems Interface) range from older 50 pin up to and greater than 80 pin connectors. SCSI is technology pre-dating IDE and ISA i believe (not sure about the last one... i have not slept much as i type this... ). A higher cost option no doubt but according to many a much safer bet... higher sustained speeds too... with the newer version of SCSI - U320. Most enterprise applications prefer this interface method in RAID configurations of all sorts. SCSI is known for its upgradability... for example from older SCSI - fast SCSI - ultra SCSI all three being able to co-exist on a common SCSI bus.

spindle speeds between 4200 - 15000 i believe

... IEEE1394a/b etc (firewire) and USB 1-2.0 i'm sure most know about as they are recent technology and use either the firewire and USB protocol. Lots of info on these suckers.

I'm sure i've even left a few out... ISA being one...but is seldom used anymore (i could be wrong).

Please understand the purpose of this thread... is only a brief guide to HDDs (Hard Disc Drive) from my perspective and by no means is accurate to the point of being quotable.

i hope somebody with a much deeper knowledge can lend a lesson or two and add to/correct all this ranting... ...


Cheers for now...