[c-nsp] power requirement for sup720 migration

[Hank Nussbacher]

On Wed, 15 Nov 2006, Jay Ford wrote:
> On Thu, 16 Nov 2006, Affan Basalamah wrote:
>> Currently we are running c6500 on :
>> - 1 x Sup1A
>> - 2 x X6408-GBIC
>> - 1 x X6248-RJ45
>> - 1 x CAC-1300
>> - 1 regular fan
>>
>> And we want to replace Sup1A to Sup720, but we are had tight budget,
>> so we are planned to replace our c6500 into :
>> - 1 x Sup720
>> - 2 x CAC-1300 (add another CAC-1300)
>> - 1 High speed fan (replace the fan)
>> - existing interfaces modules mentioned above
>>
>> I want to know whether it is going to work or not. Redundancy
>> currently is not a concern yet.
>
> No, that will not work.  The sup720 needs a high-speed fan.  The high-speed
> fan needs at least a 2500 W power supply.  Therefore, you can't run a 6500
> containing a sup720 on 1300 W power supplies, even in combined
> (non-redundant) power mode.

Remember that 1300W power supply will result in less than 1300W.  3000W 
CAC results in 2771W (see below), 2500W gets you 2331W.  SUP720 will take 
328W and the highspeed fan another 298W.  2x6408 will probably be 118W x 2 
= 236W.  The 6248 probably will take 328W.  Total = 1190W.  A 1300W PS 
will probably give you approx 1210W so you are taking a huge chance with 
this config.  I would go with a 2500W PS.

gp1#sho power
system power redundancy mode = redundant
system power total =     2771.16 Watts (65.98 Amps @ 42V)
system power used =      1807.68 Watts (43.04 Amps @ 42V)
system power available =  963.48 Watts (22.94 Amps @ 42V)
                         Power-Capacity PS-Fan Output Oper
PS   Type               Watts   A @42V Status Status State
---- ------------------ ------- ------ ------ ------ -----
1    WS-CAC-3000W       2771.16 65.98  OK     OK     on
2    WS-CAC-3000W       2771.16 65.98  OK     OK     on
                         Pwr-Allocated  Oper
Fan  Type               Watts   A @42V State
---- ------------------ ------- ------ -----
1    WS-C6K-13SLT-FAN2   298.20  7.10  OK
                         Pwr-Requested  Pwr-Allocated  Admin Oper
Slot Card-Type          Watts   A @42V Watts   A @42V State State
---- ------------------ ------- ------ ------- ------ ----- -----
1    WS-X6582-2PA        105.00  2.50   105.00  2.50  on    on
2    WS-X6582-2PA        105.00  2.50   105.00  2.50  on    on
3    WS-X6582-2PA        105.00  2.50   105.00  2.50  on    on
4    WS-X6582-2PA        105.00  2.50   105.00  2.50  on    on
7    WS-SUP720-3BXL      328.44  7.82   328.44  7.82  on    on
8    (Redundant Sup)       -     -      328.44  7.82  -     -
9    WS-X6748-GE-TX      432.60 10.30   432.60 10.30  on    on

-Hank Nussbacher
http://www.interall.co.il