1. Library Guide
  2. SL4000 Specifications and Features
  3. Power Configurations
  4. Calculate Power Supply Quantities

Calculate Power Supply Quantities

The number of power supplies you need to order depends on the power configuration (N+1, 2N, or 2N+1), card cage configuration, and number of drives.

  1. Determine the maximum power consumption of the card cage.
    Card Cage Configuration Maximum Watts

    Minimum (one controller, one root switches, three storage cards, one video card, and two fan assemblies)

    352

    Mid (two controllers, two root switches, three storage cards, one video card, and two fan assemblies)

    511

    Maximum (two controllers, two feature cards, two root switches, seven storage cards, one video card, and two fan assemblies)

    793
  2. Calculate the maximum power consumption of the drives:
    Drive Type Watts Used by Each Drive

    T10000A/B/C

    91

    T10000D

    117

    LTO

    48
    1. Determine the number of each drive type and multiply by the watts-per-drive for each drive type.
    2. Add together the watts used by each drive type to calculate the total watts consumed.
  3. Add the card cage and drive power consumptions together. Use the following tables to determine the number of DC power supplies needed.
    Base Module: Total Watts Used by All Drives Power Supplies Required for N+1 Power Supplies Required for 2N Power Supplies Required for 2N+1

    1 - 1,063

    2

    2

    4

    1,064 - 2,263

    3

    4

    6

    2,264 - 3,463

    4

    6

    8

    3,464 - 3,805

    5

    8

    8
    Drive Module: Total Watts Used by All Drives Power Supplies Required for N+1 Power Supplies Required for 2N Power Supplies Required for 2N+1

    1 - 1,200

    2

    2

    4

    1,201 - 2,400

    3

    4

    6

    2,401 - 3,600

    4

    6

    8

    3,601 - 4,443

    5

    8

    8

Example: Calculating Required Number of DC Power Supplies

This example shows how to calculate power for a library with a Base and one Drive Module with both drive types (T10000 and LTO). The Base has the minimum configured card cage (352W).

Base Module Drive Type Quantity of Drives Multiply by Watts Per Drive Total Watts Per Drive Type

T10000D

6

117

702

T10000C

6

91

546

LTO8

4

48

192

Total Drive Consumption for Base = 702 + 546 + 192 = 1,440 W

Drive Module Drive Type Quantity of Drives Multiply by Watts Per Drive Total Watts Per Drive Type

T10000C

10

91

910

LTO7

4

48

192

Total for Drive Module = 910 + 192 = 1,102 W

The Base consumes 1,792W (352 W for card cage and 1,440 W for drives). The Drive Module consumes 1,102 W.

The tables below list the power supplies required for the example library. Two tape drive DC power supplies ship standard with the Base and two power supplies ship standard with the Drive Module. Therefore, subtract two from the DC supplies required when determining what to order.

Library Power Configuration Base Module DC Supplies Required DC Supplies to Order (= Required - 2)

N+1

3

1

2N

4

2

2N+ 1

6

4
Library Power Configuration Drive Module DC Supplies Required DC Supplies to Order (= Required - 2)

N+ 1

2

0

2N

2

0

2N+1

4

2

The number of DC supplies that you need to order depends on the power configuration. For instance, if the example library had a 2N+1 configuration, it would require an order of six additional DC power supplies (four supplies for the Base and two supplies for the Drive Module). The 2N+1 also requires an additional DC supply for the rail. Therefore, you would need to order a total of seven DC power supplies