Promise Technology Pegasus3 R4 User Manual

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Technology BackgroundPegasus3 Product Manual
Stripe Size
Stripe Size, also called “Stripe Block Size,” refers to the size of the data blocks written to, and read
from,thephysicaldrives.StripeSizeisspeciedwhenyoucreatealogicaldrive.YoucanchooseStripe
SizedirectlywhenyouusetheWizardAdvancedCongurationfunctiontocreatealogicaldrive.
You cannot change the Stripe Size of an existing logical drive. You must delete the logical drive and
create a new one.
The default stripe size is 128 KB. When you create your logical drive using the Wizard Advanced option
or you create a logical drive manually, you can choose a stripe size of 64 KB, 128 KB, 256 KB, 512 KB,
and 1 MB.
See “Creating a Disk Array and Logical Drive with the Wizard” on page 112 and “Creating a Logical
Drive Manually” on page 134.
There are two issues to consider when choosing the Stripe Size:
• You should choose a Stripe Size equal to, or smaller than, the smallest cache buffer found on any
physical drive in the disk array. Selecting a larger value slows read/write performance because
physicaldriveswithsmallercachebuffersneedmoretimeformultipleaccessestolltheirbuffers.
• Ifyourdataretrievalconsistsofxeddatablocks,suchaswithsomedatabaseorvideo
applications, then you should choose that size as your Stripe Size.
Ifyoudonotknowthecachebufferorxeddatablocksizes,choose64KBasyourStripeSize.
Generally speaking,
• Email, POS, and web servers prefer smaller stripe sizes.
• Video and database applications prefer larger stripe sizes.
Target Requirements
RAID0
None
RAID5
None
RAID6
None
RAID10
None
RAID1E
None
RAID60
None
See “Migrating a Logical Drive” on page 144.

Promise Technology Pegasus3 R4 Specifications

General

Internal	No
Chassis type	Tower
Cooling type	Active
Device class	Small & Medium Business
Fan diameter	92 mm
Certification	CB, UL, cUL, TUV , BSMI, SPRING, BIS FCC, CE-EMC, VCCI, BSMI, RCM KCC
Product color	Black
LED indicators	Yes
Number of fans	1 fan(s)
Airflow (imperial)	70 cfm
Management platform	Pegasus Utility
Cable lock slot type	Kensington
RAID levels	0, 1, 1E, 5, 6, 10
Data transfer rate	40 Gbit/s
Storage drive size	3.5 \
Storage drive capacity	4000 GB
Storage drive interface	Serial ATA
Installed storage drive type	HDD
Supported storage drive types	HDD & SSD
Total installed storage capacity	16 TB
Maximum supported storage capacity	- TB
Number of storage drives installed	4
AC input voltage	100-230 V
AC input frequency	50 - 60 Hz
Number of power supply units	1
Power supply unit (PSU) capacity	250 W
Thunderbolt version	3
Thunderbolt ports quantity	2
Storage temperature (T-T)	-40 - 70 °C
Operating temperature (T-T)	5 - 35 °C
Storage relative humidity (H-H)	5 - 95 %
Operating relative humidity (H-H)	10 - 95 %
Cables included	AC, Thunderbolt

Weight and Dimensions

Depth	188 mm
Width	248 mm
Height	195 mm
Weight	6800 g