cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
2057
Views
5
Helpful
9
Replies
Pedro Morais
Beginner

CRS Power Consumption

Hello all,

I'm trying to find info regarding the power consumption of a CRS. However I cannot find any information about the following CRS modules (no datasheet):

CRS-8-FC/S

CRS-8-FC-140/S

CRS-8-LCC-FAN-TR

Any idea of where can I find this info?

Thanks!

Cheers,

Pedro

1 ACCEPTED SOLUTION

Accepted Solutions
Nicolas Fevrier
Cisco Employee

Hi Pedro,

AFAIK, no public doc available on this.

CRS-8-FC/S: 185W

CRS-8-FC-140/S: 90W

CRS-8-LCC-FAN-TR: 150W nominal

Kind regards,

N.

View solution in original post

9 REPLIES 9
Nicolas Fevrier
Cisco Employee

Hi Pedro,

AFAIK, no public doc available on this.

CRS-8-FC/S: 185W

CRS-8-FC-140/S: 90W

CRS-8-LCC-FAN-TR: 150W nominal

Kind regards,

N.

Hi Nicolas,

Thanks for your reply!!!! I notice a very big difference between FC and FC140... Nice to see that contrary to the PLIMs/MSCs/FPs, the power consumption is lower in the new FCs.

Thanks!!!!

Cheers,

Pedro

Hi Pedro,

the lower consumption is simple to explain. In the FC/S we used to have 3 ASICs for each fabric stage (S1, S2 and S3) per card.

In the FC-140/S, we collapsed these 3 ASIC into a single one (S123) reducing the power usage significantly.

Cheers,

N.

Thanks for your explanation Nicolas!!!

Cheers,

Pedro

Hi Nicolas,

One last question.. Why does the value reported by the router are so diferent (lower) then the ones I got in the datasheets and in power calculator tool?

For example, from my calculations, for the configuration I have:

Nominal Power: 4636W

Max Power: 5260W

However when collecting the output from the router, i got:

RP/0/RP0/CPU0:CC-LAB01# admin show env power-supply

Wed Jun  5 18:58:04.483 WEST

                     Power Supply       Voltage               Current

                     DC-PEM DC-PEM                  (V)          (A)

Zone 1:               [A], [B] 52.712, 53.005   10.237, 10.655

Zone 2:               [A], [B] 52.810, 52.614   7.939,  7.834

Zone 3:               [A], [B] 52.516, 52.418   8.565,  7.312

Total Current:   52.542 A

Total Power  : 2768.897 W

That is a huge diference...

Thanks!!!

Cheers,

Pedro

Hi Pedro,

all values produced by the power calculator are "absolute worst case" and that's for this particular worst case that the system should be dimensioned. (power consumtion varies a bit depending of the activity but most of the time, the peak consumption is at the boot up of the chassis).

Cheers,

N.

Hi Nicolas,

I totally understand that, however the difference between the "real" power and the nominal/max power is huge! Even if we dimension the power system for the nominal power it is almost the double of “real” power. And this is really hard to explain to the costumer… Can you help me with that???

Thanks.

Cheers,

Pedro

Hi Pedro,

I'm afraid it's going to be difficult to "prove" this point.

As an example, I'll take the fan trays: at nominal speed (4000rpm), they use 151W each ---> 302W

When the system boots up the card are pushed to full speed (7500rpm) and use 860W each ---> 1720W.

Then the line cards PLIM+MSC140 are defined for 450W but typical load is 320W, that a 130W difference (x8 slots).

Etc, etc...

I strongly advise that your customer doesn't try to "push to the limit" here and trust the values provided.

Kind regards,

N.

Thx for your help Nicolas!

Cheers,

Pedro