20x 50cm 7030SMD Led strips power supply question

[supergogetassj5]

So I've got 10 meters (20x50cm) of 7030SMD Led strips.

The seller writes:

• Lumen: 7030 White / Cool White about 115 lm/W;  Electric power: 19W-22W/1meter

So its ~350W of power. Thats not small but OK. Im looking at my local electronics store and all I see is 250w maximum of power supplies for LEDs. So I have to get two of them? Or am I calculating something wrong?

Also, maybe I can use old PC PSU? But I know there is this thing called amperes? What that has to do with everything? Sorry I'm kinda very basic on electronics...
Thanks

[madires]

20W per meter seems to be quite high. I'd take one 50cm strip and power it by a lab PSU or a 12V PSU plus a DMM for measuring the current.

[LaurentR]

Sounds about right. Looking at other vendors, they have 50cm strips of 36 LED, each LED quoted at 0.3W, so 72led/m x 0.3W/led = 21.6W/m

350W is ok, but at 12V, that's 30 amps, which is quite a bit. You will likely have to use multiple 12V outputs of your PSU (check the ratings) and carefully pick your wire gauge to reduce IR drop (and also keep wire temp low).