Pomfrit

Thank you for everything man really helped me alot will all your help:)

I would just try that mini rx 570, you could confirm if those cards where faulty.

In your case I would try finding a seller near you that is willing to let you verify the gpu works correctly in their system, because you just might have stumbled on unreliable sellers that sell dead(ish) parts.

SSD won't affect gaming performance, just faster loading and overall better/snappier experience using your pc. SSD these days is a must, even smaller capacity.
That's a bit of a dick move... You should have tested it in on some friends pc before selling.

Try it in some friends pc if under clocking doesn't work. Changing the paste won't help, your temps are fine. You can try putting the card in different slot though.

He may have degraded the chip while mining and it cant hold the standart clocks anymore.
 
Try underclocking the core and memory and see if this fixes it

The first video breaks my heart and wallet  

With a volt/multimeter.

Heaven bench is fine too. Set fans on auto.

It says 6GB,Speccy is unreliable.

No you are 100% fine, I was just providing additional info. SLI is when you use 2 GPU's and connect them with an SLI bridge for enhanced performance, the 1060 series does not support SLI but this changes nothing with how you intend to use the system or the motherboard. 

In Anandtech's review of the GTX 970 they measured 300W total system power consumption in Crysis 3, a game that hits both the gpu and cpu hard, in a system with an overclocked i7-4960x. That's a cpu with a massive 130W stock power consumption, much less what it consumes when overclocked.
 
https://www.anandtech.com/show/8568/the-geforce-gtx-970-review-feat-evga/15
 
That seems like a ton of headroom to me.

Thanks ur awesome:)

First part yes, 2nd part no - how and why? That is more a question of its design in general.
And both of it is completely irrelevant considering the question whether it will or will not be suitable for the task.

Yeah your 450w should be good enough. I use a corsair cx 500 watt psu and have my 1060 overclocked to the max and it runs no problem.

The only issue I have had with purchasing compute usage cards is that they typically need repasted when you get them. 

buy it, the risk of damage or issues is the same as buying any "non-mined" gpu. 

Generally mining cards are run undervolted to decrease heat output and power consumption, so I'd say they have been stress-tested for you.
 
I have had 2 mining cards, have recommended them to some others, haven't had or heard any abnormal issues.

Probably fine. Pay with Paypal if you're worried about it not working and it's getting shipped to you.
If you're buying it locally, you'll probably just have to trust him.

It's probably fine if you ask me.

Yes. You will be fine, your psu is not amazing but not a fire hazard also.

In my opinion with psu,  if you have a cheap unit its risky no matter what you slap in your system.  Not sure what master watt unit you have but this is a good reference.
 

You should be able to run up to a rx 580,  but i wouldn't look at overclocking much of anything with a 450 watt unit.  I am currently running a gtx 1060 6gb with a cx450 on my kids rig.

970 has 4GB VRAM, can make quite a different in today's games.
 
Actually I replaced mine with a 1070 basically only because of RAM initially. On the 970 was able to play several current games at 4K in terms of FPS, but several choked only due to insufficient VRAM. 

GTX 970 isn't that much better than a 1050Ti, you wouldn't be gaining a whole lot.