Ultra-Dense Server Deployment in Racks

Compaq Ultra-Dense Server Deployment in Compaq Racks 41
128H-0400A-WWEN
3.8 Configuration-H: 35 De-rated Servers, Stand-Alone Rack,
24A High Voltage PDU
This configuration is the same as Configuration-G, except one PDU was removed for easier cable
installation. The following calculation verifies supporting 42 servers (de-rated Power Budget) with 24A
High Voltage PDUs:
Two PDUs will be supporting 35 servers, 5 KVM switches and 1 FPD. For simplicity, assume the KVM
switches and the FPD consumes about the same amount of power as the servers. Therefore, each PDU will
need to support up to 21 servers or devices. A 24A Low Voltage PDU supporting 21 devices can allocate
each device with maximum current of (24/21=) 1.15A. Assuming 208V, the allocated maximum input
power for each device will be
1.15A * 208V = 240W
The maximum thermal dissipation per device will be
240W * 3.41 = 818 BTUs/hour
For 42 devices, the total thermal dissipation will be (818*41=) 33,555 BTUs/hour
.
In Section 2.2, a fully configured system was measured to consume lower than 200W (Table 2-3, Server
Configuration-5). Hence, if each de-rated server configuration input power is lower than 240W then 42
devices (35 servers and 6 other devices) can be supported via this configuration summary.
Configuration-H Summary
Rack Contents
Units
35 servers with all fixed or all sliding rails with cable trays
5 KVMs, 1 FPD, 1 Keyboard, 1 Keyboard tray
2 High Voltage 24A PDUs vertically mounted in the side panel compartments.
Internal Cables
22 Y-power cords going to 2 PDUs in the side panels
40 KVM cables
: [See Figure 4-22 for the cabling diagram]
35 from each server to a corresponding Server Console Switch in the rack
4 from four Server Console Switches (KVM 1-4) to the top-level Server
Console Switch (KVM 5) to cascade the KVM switches.
1 from the top-level Server Console Switch to the FPD and the
keyboard/trackball (different cable)
Cables External to Rack
35 (data) network cables from on-board RJ45 to external switches, assuming
use of only one LAN connection per server.
2 input power cords from the rack to external power outlets
Site Utility Requirements (worst-case)
Power: 2 dedicated 200V-240V 30A branch circuits.
Thermal: up to 33,560 BTU [This number is a worst-case. The actual
BTUs/hour will depend on the OS/application software running and the
server hardware configurations.]
Weight: up to 1,555 lb (with sliding-rails) [The network cables are not
accounted for since most implementations route these cables to the
ceiling-hung cable rails outside of the rack.]
22 Server 20
21 Server 19
20 Server 18
19 Server 17
17 Server 16
18 KVM 2 / Kybd
16 Server 15
15 Server 14
14 Server 13
13 Server 12
12 Server 11
11 Server 10
10 Server 9
35 Server 30
36 Server 31
34 Server 29
33
32 FPD
30 Server 27
31 Server 28
29 Server 26
28 Server 25
27 KVM 3
42 KVM 5
40 Server 34
41 Server 35
39 Server 33
38 KVM 4
37 Server 32
26 Server 24
25 Server 23
24 Server 22
23 Server 21
8 Server 8
9 KVM 1
7 Server 7
6 Server 6
5 Server 5
4 Server 4
3 Server 3
2 Server 2
1 Server 1