As a "rule of thumb" you will need 1/2W of the PC to approx. the pc output.
The "problem" w/ the series strips is the terminating resistor on every 3 in series wastes power. Also, depending on the design, it will be at a lower output than you would get w/ a constant current array.
One in order to assure no overheating and 2)to make up for power fluctuations
When a fixture is designed on a solid al heatsink, and lower density, they can tweak the resistor to allow full utilization of the diodes potential (in the case of say a .5W LED the LED "useage" can approach .5w. with "strips" you may only have .2-.3W effective)
As you probably know, the 10W "chips" are just a 3x3 array of 1w diodes.
There are other types though
Just an example of the 3x3 kind.
Color: Warm white
Forward Voltage (VF): DC9-12V
Forward current (IF): 1050MA
Out put Lumens: 800-900LM
Color Temperature: Warm white(2800K-3200K)
Beam Angel: 140 degrees
The 1 Ohm 2W resistor per chip seems pretty accurate.
Though as a precaution I'd consider 5W resistors..Still in the 1-1.5Ohm range.
That is just me personally though.
If you err on the high side on the resistance you can still get a "tweak-able" power supply and increase the output voltage to over 12V..
You didn't state your ps specifics BTW.
It needs more than 240W capability to utilize all 5 channels effectively
You can do a rough calculation of power output of the LED's on the strips by getting the number off the smd resistor and seeing its ohm rating..
the 5630 did not see brighter than the others. In fact they seemed a little dimmer.
Yea a lot depends on diode quality, terminating resistor, and internal wiring resistance and losses.. which is why a double tap is worth considering.
As you are well aware visual look isn't very accurate..