HALF DEPTH 48U “2 Meter Tall” CABINET

6/30/15

48U CABINET - HEIGHT

48UNEW LAYOUT

2 M78.74”

48USTANDARD

LAYOUT

2.23 M90.5”

The most sought after height of cabinets is 2 Meters. The reason for this is that many elevators in use around the world have doors which are just a little over 2 Meter tall.

Load permitting, the cabinet on the left would be able to take the elevator. The 48U cabinet on the right would require hoisting down an elevator shaft.

A standard 42U cabinet is even taller than the design I have created on the left. As it is 80”-82”or 2.03m-2.08m tall.

48U CABINET - DEPTH

48UNEW LAYOUT

48USTANDARD

LAYOUT

Reguaging Cabinet / Server Depth is a Density Play. I have created a ½ Depth Server which is specifically suited to accommodate 4 SSD’s in a 1U server.

So the ½ Depth Cabinet is 24” deep as opposed to a Standard Depth cabinet which is typically 36”- 48” deep.

Significant Cabinet cost savings on both Servers & Cabinets reduce the TCO.

0.6 M / 24”

1 M / 40”

48U CABINET - FUTURE

1) The best metric to measure when density changes are requisite is “Does the server have the minimum level of mass storage” ?

2) Does the mass storage have the persistence / longevity that is a game changer ?

3) How does this improve my over all data center density ?

4) How does this improve my over all switch utilization ?

5) Can I improve my floor topology to increase cabinet density ?

6) What kind of savings can I expect at the cabinet level and at the ?

7) PDU Power considerations. What currently accepted AC power topology should I use ?

48U CABINET – SERVER STORAGE DENSITY

2.5” SSD 7mm

List of possible options.

1. EATX, 4 2.5” SSD’s2. ½ Width EATX, 8-12 2.5” SSD’s3. Micro ATX, 8 2.5” SSD’s4. Mini ITX, 12 2.5” SSD’s

Depending upon which Mother Board you select, up to 24 TB of Flash can be deployed in this 1U server.

48U CABINET – DATA CENTER CABINET DENSITY

Notice that the SSD’s are Sled-less. They use a pull tab to select one of the 4 drives in the stack. Some might say this is breaking the rules but I challenge the rules because drive sleds cost money. It all about lowering the TCO.

1U Blindmate AC 1/2 Depth Server

48U CABINET - FUTURE

50 42U Cabinets

Using a two tile spacing for hot and cold isle, the floor below is 24’ Wide by 44’ Deep.This configuration yields up enough space for 2,000 servers and 100 Switches with a switch port under utilization of 6 ports per cabinet or 300 total ports under utilized. This is like purchasing 12.5 more switches than you actually need.

48U CABINET - FUTURE

Not changing the floor space we see with an additional 2’x2’ floor tile at the front we can squeeze in 7 rows. We have 46 servers an 2 switches in each cabinet. In this configuration we have a total of 3220 servers and 140 switches. Switch port under utilization of 2 per cabinet or 140 total ports under utilized. Note: At least 1 port per switch should be left free so that there is a port for a laptop on each switch. So in this case we have a perfect utilization model.

70 48U Cabinets

48U CABINET – PDU CONSIDERATIONS

When it comes to PDU’s, I prefer using 208 3P Vac as each standard whip (also called a power cord) that is connected to the cabinet yields 7.5KW of derated Power. For a cabinet of the density as described above it will take 1 to 2 of these cables. Using 110 Vac is truly a mess and a supreme waste of copper !

The 3 Phases of power from a 208 Vac line yields 3 120 circuits which can be broken down into legs which plug into each server. In a 48U server there are 16 Phase A Power Sockets, 16 Phase B & 16 Phase C for a total of 48 power sockets. So purchasing 48 socket 208 3P Vac works fine if your maximum power draw is 7.2KW.

If you can’t find a dual whip 208 Vac 3P PDU with 48 sockets, you may need to purchase 2 24 socket 208 Vac 3P PDU’s.

Careful Power Planning is necessary to ensure the best phase loading cabinet by cabinet and row by row. The reason for this is that by creating uneven loads on one leg of the power it cause an affect called loping in the transformer. If the transformers are not derated properly then you will have over temp issues. The best way to go is “Phase Perfect Loading”. This is another topic for another paper.

48U CABINET – AC POWER

3P Power Calculation.

I x E x 3P Constant = Power / Watts Total Power Derating (80% Rule) Watts x .8

30A x 208 Vac x 1.732 x .8 = 8.6KW per Whip

Where:I = Electrical Current in AmpsE = Electrical Potential in Voltage3P C = 3 Phase Constant = 1.732Derating = 80% of total Power in Watts (stranded Power)

208 Vac 3P 30A Service

= 8.6KW per Whip

208 Vac 3P 25A Service

= 7.2KW per Whip

208 Vac 3P 20A Service

= 5.7KW per Whip

Thank You !

48U CABINET