[SOLVED] GTX 970 Power Consumption

Aug 25, 2019
Before I start asking question, I'll apologize if the thread it's not in the correct section. It seemed as the most accurate one for the question I have.

Ok, so the thing is I have this MSI GTX 970 (https://www.msi.com/Graphics-card/GTX-970-4GD5-OC.html), and on the specs page it says that the max consumption is 145W. I have two Lenovo PSUs rated at 500W and with a recommended maximum load of 280W. So for the sake of tinkering and having some fun (I don't really need the card nor I will regret if it blows up) I was wondering if it was some way of using both PSUs at the same time: One powering my main PC for this test (i7-860, 4GB DDR3 Memory, 500GB HDD) and the other one ONLY powering my GTX 970. The only detail is that I don't know if both PSUs have to turn on at the exact same time or I can boot up the GPU's one first and the System's one. If so, do you have any idea on how to synchronize the boot up? I really want to see if I can pull this up with this old hardware.

Sorry for the long and bad redacted post, English is not my strongest skill. And thanks if you can help me in any way in this sort of "project" I want to do.