Is my GPU getting enough power?

[Sketchice]

I'm just wondering since my PC has been restarting recently and after a lot of googling I have pinpointed it to being a power problem.

I'm new to building computers and built my first a bit over a year ago with the help of my Dad and everything worked fine with the GTX 660. Recently I upgraded to a GTX 970 and while playing graphically intensive games like Assassins Creed 4, Far Cry 4, CoD: Advanced Warfare etc. it plays for about 30 - 60 minutes before restarting without any error warnings. This is kind of confusing since both cards require a similar amount of power. Older and less pretty games like Mortal Kombat, Counter Strike, Skyrim etc. have no effect and I can play them non-stop.

It's not overheating, the max temperature is about 65C before restarting which to my knowledge is fine. Although if it isn't please yell at me because in truth I'm just going off of stuff I've googled here.

One thing I will add is my PSU only has one 6-pin so I need to use a molex -> PCIe 6-pin plug and one of the things I tried is using two of them, this resulted in the graphics card barely functioning, the restart times being earlier and some sound glitches. So what I'm trying to get at is that I might be plugging these in wrong some how. Is there a specific way to plug them in?

Some Specs

Spoiler

Operating System: Windows 8.1 Pro 64-bit
System Manufacturer: Gigabyte Technology
System Model: Z87X-D3H
BIOS: F5
Processor: Intel(R) Core(TM) i7-4770 CPU @ 3.40ghz (8 CPUs), ~3.4GHz
Memory: 8192MB RAM
DirectX Version: DirectX 11

Display Specs

Spoiler

Name : NVIDIA GeForce GTX 970
Manafacturer: NVIDIA
Chip Type: GeForce GTX 970
DAC Type: Integrated RAMDAC
Device Type: Full Display Device
Approx. Total Memory: 7980MB

Click here for PSU sticker (large image)

Any help is appreciated, also just a quick question since I only know the bare minimum about the PSU. If each molex is able to produce 75W then how much does the molex -> PCIe 6-pin produce? I learned that a typical 6-pin produces 75W but if it only produces that little amount then why do I need to plug the molex -> PCIe 6-pin into two molex cables? That would make sense for an 8-pin, I'm just confused.

Anyway, thanks in advanced for anyone who helps. I'll try to respond as soon as possible but I'm on my phone.

 

[ko888]

You're wrong about the power requirements.

For a system using a single GeForce GTX 660 (non-Ti) graphics card NVIDIA specifies a minimum of a 450 Watt or greater system power supply that has a maximum combined +12 Volt continuous current rating of 24 Amps or greater and that has at least one 75-Watt 6-pin PCI Express supplementary power connector. (Minimum system power requirement based on a PC configured with an Intel Core i7 3.2GHz 130 Watt TDP processor.) An exception is the MSI GeForce GTX 660 HAWK 2 GB. It requires two 6-pin PCI Express supplementary power connectors.

For a system using a single GeForce GTX 970 graphics card NVIDIA specifies a minimum of a 500 Watt or greater system power supply that has a maximum combined +12 Volt continuous current rating of 35 Amps or greater and that has at least two 75-Watt 6-pin PCI Express supplementary power connectors. There are some non-reference design cards that require one 75 Watt 6-pin and one 150 Watt 8-pin PCI Express supplementary power connectors or just one 150 Watt 8-pin PCI Express supplementary power connector. (Minimum system power requirement based on a PC configured with an Intel Core i7 3.2GHz 130 Watt TDP processor.)

The number of PCI Express supplementary power connectors on the graphics card clearly shows that.

Your Hytec HYT-550A (OEM: Huntkey based on the HK400-12AP) is clearly insufficient to do the job properly. The proof is that when you tried to use Molex to PCI-E adapters and the card ended up barely functioning. The age of your PSU would also indicate a loss of maximum capacity.

 

[Alan Caldwell]

Yeah, it's the PSU because I've never heard of the brand Hytec. Get a better PSU like an XFX 550w etc.

 

[Sketchice]

You're wrong about the power requirements.

For a system using a single GeForce GTX 660 (non-Ti) graphics card NVIDIA specifies a minimum of a 450 Watt or greater system power supply that has a maximum combined +12 Volt continuous current rating of 24 Amps or greater and that has at least one 75-Watt 6-pin PCI Express supplementary power connector. (Minimum system power requirement based on a PC configured with an Intel Core i7 3.2GHz 130 Watt TDP processor.) An exception is the MSI GeForce GTX 660 HAWK 2 GB. It requires two 6-pin PCI Express supplementary power connectors.

For a system using a single GeForce GTX 970 graphics card NVIDIA specifies a minimum of a 500 Watt or greater system power supply that has a maximum combined +12 Volt continuous current rating of 35 Amps or greater and that has at least two 75-Watt 6-pin PCI Express supplementary power connectors. There are some non-reference design cards that require one 75 Watt 6-pin and one 150 Watt 8-pin PCI Express supplementary power connectors or just one 150 Watt 8-pin PCI Express supplementary power connector. (Minimum system power requirement based on a PC configured with an Intel Core i7 3.2GHz 130 Watt TDP processor.)

The number of PCI Express supplementary power connectors on the graphics card clearly shows that.

Your Hytec HYT-550A (OEM: Huntkey based on the HK400-12AP) is clearly insufficient to do the job properly. The proof is that when you tried to use Molex to PCI-E adapters and the card ended up barely functioning. The age of your PSU would also indicate a loss of maximum capacity.

Thanks a tonne ko. What's recommended for my particular card?

 

[ko888]

Thanks a tonne ko. What's recommended for my particular card?

EVGA SuperNOVA 750 G2 220-G2-0750-XR for $69.99 after $25.00 rebate card would be a superb deal. It has fully modular output cables and is fully Intel Haswell processor compatible.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817438017

CORSAIR HX series HX650 for $59.99 after Promo Code and $30.00 rebate card. It has semi-modular output cables and is fully Intel Haswell processor compatible.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139012

 

[Sketchice]

Thanks a tonne ko. What's recommended for my particular card?

EVGA SuperNOVA 750 G2 220-G2-0750-XR for $69.99 after $25.00 rebate card would be a superb deal. It has fully modular output cables and is fully Intel Haswell processor compatible.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817438017

CORSAIR HX series HX650 for $59.99 after Promo Code and $30.00 rebate card. It has semi-modular output cables and is fully Intel Haswell processor compatible.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139012

Thanks again. You're a life saver and a half