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45 ssd selection guide appendix, Step-by-step calculation – Hatteland Display HT B22 (Fanless) User Manual

Page 45

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45

SSD Selection Guide

Appendix

IND100077-130

Calculation of required size of SSD (Multi-Level Cell - MLC) device)

The table below details the write endurance of the an enterprise environment. All values are verified by Hatteland

Display during the qualification / selection process.

Write Endurance Specifications

Intel® SSD 320 Series

Write Endurance Specifications

Current 2.5” SSD (MLC)

Device Size

Value in TBW (Terabytes)

Device Size

Value in TBW (Terabytes)

40 GB

5

80 GB

45

80 GB

10

120 GB

70

120 GB

15

160 GB

100

160 GB

15

240 GB

140

300 GB

30

300 GB

225

600 GB

60

600 GB

330

Write endurance is measured while running 100%

random 4KB (4096 bytes) writes spanning 100% of

the drive using Iometer.

JESD218 standard1 and based on JESD219 workload.

Formula for calculating disk size:

z

=

y

*

x

Where

y

= Requested minimum lifetime (with respect to wear out, [year]).

Where

x

= Data rate (GB /per year).

Where

z

= Total amount of data written data to SSD during its whole lifetime.

Step-by-Step Calculation

Step 1: Measure (preferred) or estimate data rate

y

, [GB /per year].

Step 2: Define minimum expected lifetime for SSD device

x

[year].

Step 3: Calculate total amount of data written to the SSD during its whole lifetime,

z

=

y

*

x

.

Step 4: Use table,

column 2

, the

z

value shall be less or equal to the value in the table to achieve requested lifetime.

Write Endurance Specifications

Intel® SSD 320 Series

Write Endurance Specifications

Current 2.5” SSD (MLC)

Device Size

Value in TBW (Terabytes)

Device Size

Value in TBW (Terabytes)

40 GB

5

80 GB

45

80 GB

10

120 GB

70

120 GB

15

160 GB

100

160 GB

15

240 GB

140

300 GB

30

300 GB

225

600 GB

60

600 GB

330

Step 5: Select the SSD device,

column 1

, which corresponds to the selected value in

column 2

.

Step 6. Check that the size of the selected SSD is greater than required size of the SSD, if not select the size of the

SSD that match customer requirements.