VANGO(VL40)
SAMSUNG HARD DISK DRIVE
Overhead
Time to perform the real order for controller, host adaptor and drive.
The faster overhead is,
the faster performing time.
Overwrite
Recorded data erased by overlapping the existing data.
Parking
Zone
= Landing Zone
Partition
When we use one HDD for multi ones dividing section logically, every memory section is
partition, For example, 2.5GB HDD can be used for one 2.1GB computer and one 400MB.
PCBA
Printed Circuit Board Assembly. Kind of
IC and Chips are Soldered on board and make run
HDA, PCBA is a half-finished goods.
PCMCIA
Personal Computer Memory Card International Association.
Pentium
586 Microprocessor to apply IBM type developed by Intel
Pentium
Pro(P6,686)
Pentium's next CPU. 5.5 billion transistor integrated. There are 150, 166, 180, 200MHz.
Peripheral
Additional device except basic CPU. There are Disk Drive, Tape Drive, CD-ROM.
PIO
Programmed Input/Output.
Pivot
Bearing
Roll bearing is fixed on the rotating center of ARM.
Plated
Media
Disk is covered with hard metal alloy rather than disk Iron-oxide compound.
The more data could be stored.
Platter
Metal disk record data within HDD
POH
Power On Hour, used for MTBF.
Power PC
RISC type CPU is developed by IBM, Apple and Motorola commonly.
PQT
Pre-qualification test
PRML
Partial Response Maximum Likelihood, this is a read/write method to improve recordi density and
data transferring rate. This method enable to improve capacity as 30% more than the existing
data transferring by using Peak Detection.
PVT
Production verification test
QMS
Quality management system. Overall quality management system
RAID
Redundant Arrays of Independent Disks.
To protect a sudden data damage, connect HDD in
parallel and diverge data , that is high speed back-up device enable to improve data
preservation and low speed access for tape the problem of the current back-up device.
RAM
Random access Memory. Semiconductor memory enable to input and search,we have DRAM
and SRAM.
Read cache
Look-ahead method is not only reading data requested from host but also reading- ahead
continuous data to buffer sequentially,
We improve data transferring speed because we don't
need to read again in time host request information pre-read by applying for file's sequential
saving method.
Read
Sector/Read
multiple/Rea
d DMA
Order of reading all data from HDD, read sector occur interrupt per every sector transferring,
read multiple occur interrupt per designated sector number by set multiple order. Also read DMA
occur interrupt only one time after transferring data from host request. For example, 4 is chosen
by set multiple and host need 10 sectors then the below picture draw how to occur Interrupt.
Recoverable
Err/Uncovera
ble
Err/Correcta
ble Err
Similar to Soft Hard err. Recoverable err means it is possible to read normally though data was
read wrong, unrecoverable err means it is impossible to recover error by any means.
Correctable err is belong to Recoverable err, this is recovered by software ECC.