170w VS 90w

[Rockrz]

I just got a Thinkpad T530 that I'm setting up for someone and it came with a 90 watt power supply.

It is an I7 with Nvidia graphics and 16gigs of Ram...

I have one of these personally and it came with a 170 watt power supply and if I remember right mine won't function when I try to use a 70 watt

So, what's the difference here... shouldn't a 170 watt power supply have been sent with this one I just received?

Or, since it seems to work OK as is... is this not a big deal?

I'd like to know because I want to get an extra power supply for my friend who will be using this (I always get an extra on just to have on hand...)

[rkawakami]

From looking through some of the old PSREF documents, the T530 w/Nvidia should have shipped with a 90W supply. If in doubt, consult the large label on the bottom of the machine and see what it says after the 20V ---. There should be a current rating, in amps (A). Multiply that current number by 20 and that will tell you what the (minimum) wattage you should be using.

[Rockrz]

OK, thank you for the clarification!

[RealBlackStuff]

AFAIK the 170W (with "regular" barrel-type DC-plug) was issued only for W700, and (with "keyed" barrel-type DC-plug) for W520 + W530 with extreme quad-core CPU.
The W510 and the dual-core W520/W530 models "only" need the 135W charger.
Newer/later models have flat/slim DC-plugs and soon there will be Type-C.

Also, a lot of newer machines don't have such a label anymore.

[Rockrz]

Yeah, I personally have 3 of these older Think Pads and one of them has the W530 with extreme quad-core CPU so it came with the 170 watt power cord.