Power supply with 2pcs. 6-pin connector but GTX 1070 has one 6-pin and 8-pin.

[Battousai01]

Hi guys, I just bought an MSI GTX 1070 and my current power supply is a Seasonic SS-430B. The GTX 1070 has one 6pin socket and one 8pin socket, see image below.

However my Seasonic power supply has 2pcs. 6-pin PCI-E connector, an extra 1pc. 4-PIN and an 8-PIN connector for the motherboard only.

My question can my power supply be used with the GTX 1070? If yes how can we use the extra 6-pin connector?

Thanks in advance for any replies.

 

[crashtech]

There are adapters that go from 4-pin Molex to 8-pin PCIe power, and also from 6-pin to 8-pin PCIe. If one wasn't included in your GPU bundle, you'll need to locate one. A 430W PSU, even a Seasonic, is a bit small for a PC with a big GTX 1070, generally speaking. It's probably okay, but you don't have a lot of safety margin.

 

[Battousai01]

There are adapters that go from 4-pin Molex to 8-pin PCIe power, and also from 6-pin to 8-pin PCIe. If one wasn't included in your GPU bundle, you'll need to locate one. A 430W PSU, even a Seasonic, is a bit small for a PC with a big GTX 1070, generally speaking. It's probably okay, but you don't have a lot of safety margin.

Hi crashtech, thank you for the reply, yes I am considering the 6-pin to 8-pin adapter but I believe the PSU or the graphics card should have those adapters or the plus 2-pin in the PSU at least but I don't have those, I might as well buy one.

I have checked and my Seasonic SS-430B is compatible and can run the GTX 1070 in normal use, I don't have any plans in overclocking, btw, I have a mini-ITX build an an i7-7700 CPU plus 3pcs. SSD's

 

[Battousai01]

Also, guys, can I just insert the extra 6-pin to the 8-pin in the GTX 1070? so basically, I am attaching two 6-pin connector from the PSU into the 6-pin and 8-pin of the GTX 1070 respectively, it seems the 6-pin fits the 8-pin. Although I will not try this until I confirm it is safe.

Or what is safer with the option suggested by crashtech:

1. 4-pin molex to 8-pin PCIe power

or

2. 6-pin to 8-pin PCIe conector

 

[crashtech]

The GPU probably has a circuit that will detect the missing grounds if you try to only insert the 6-pin connector into the 8-pin spot. This circuit will prevent the GPU from running. Some kind of adapter is surely necessary, unless you want to rig something to ground the extra pins, which is not recommended.

 

[Battousai01]

The GPU probably has a circuit that will detect the missing grounds if you try to only insert the 6-pin connector into the 8-pin spot. This circuit will prevent the GPU from running. Some kind of adapter is surely necessary, unless you want to rig something to ground the extra pins, which is not recommended.

Thanks again, I have now an 6-pin to 8-pin adapter and will test later. As for what you mentioned on "safety margin" what are the things to consider here given that I have a Seasonic with 430 watts?

 

[buellersdayoff]

Just don't go running things like prime 95 and furmark at the same time, for gaming and general usage 430w should be enough

 

[Battousai01]

Thanks guys for the replies. I now want to put this case to rest but before that I want to know some answers to logical questions I have which are:

The 6-pin from the PSU supplies 75w of power and 8-pin supplies 150w (correct me if I am wrong)

According to MSI, the GTX 1070's power consumption is 150 watts, this is also the same on nVidia's site which states that the 1070's requirement is 150 watts:

1. If the GTX 1070 consumes 150 watts, why are there two power connectors on the card (one for 75w and the other for 150w) It doesn't make sense. Does it mean I can use one 8-pin connector only to satisfy the 150w requirement?

2. The manual vaguely says that we should connect both 6-pin and 8-pin "if any" if that is the case isn't it that you will be supplying both 75w and 150w to the card simultaneously wherein the card only requires 150w? If you connect the two then you are supplying 225watts.

3. Can I only use the 8-pin connector (using a two 6-pin to 8-pin adapter which is what I have)? theoretically this will supply the required power of 150watts right? This will also make me use all two 6-pin power cables available from my PSU.

4. I also read on a different thread that if my PSU only has two 6-pin connector, then I can substitute the 8-pin with a 6-pin to 8-pin adapter, this will theoretically provide 75watts + 75watts power, BUT the card has 8-pin connector which should receive 150watts. Can I just use one 8-pin connector (see question 3 above)

5. Most forum answers tells me that if the PSU has no 8-pin connector for your graphics card then you should replace it. Isn't it over simplification or is that the best course of action?

Lastly I tried Seasonic's PSU calculator and it says my overall power requirement is around 300 watts way below 430 and it recommends their 520w PSU.

My setup is:

i7-7700
8GB RAM
MSI GTX 1070
3 SSD drives
mini-ITX

 

[Bacon1]

Not sure exactly which MSI 1070 you have but here are three that all use over 150w:

MSI 1070 Gaming X: 175w avg, 193w Peak

MSI 1070 Gaming Z: 175w avg, 194w Peak

MSI 1070 Quick Silver: 173w avg, 192w Peak

So yes, it looks like 170+ avg / 190+ peak is where your card will be out of the box, any OCing will raise it higher.

Also your 7700k will use quite a lot of power when OC'd - 150w + for 4.5ghz, 180w for 4.8ghz - http://www.anandtech.com/show/10968...-review-the-new-stock-performance-champion/11

So you might want to pick up a bigger / newer PSU.

 

[Battousai01]

Not sure exactly which MSI 1070 you have but here are three that all use over 150w:

MSI 1070 Gaming X: 175w avg, 193w Peak

MSI 1070 Gaming Z: 175w avg, 194w Peak

MSI 1070 Quick Silver: 173w avg, 192w Peak

So yes, it looks like 170+ avg / 190+ peak is where your card will be out of the box, any OCing will raise it higher.

Also your 7700k will use quite a lot of power when OC'd - 150w + for 4.5ghz, 180w for 4.8ghz - http://www.anandtech.com/show/10968...-review-the-new-stock-performance-champion/11

So you might want to pick up a bigger / newer PSU.

Hi Bacon1, thanks for the reply, I have the MSI Geforce GTX 1070 Gaming X. Also, I have an i7-7700, not the k version. I will also not be doing any overclocking, probably normal use for rendering and some moderate gaming.

 

[Battousai01]

I am partly considering getting a new PSU aside from the power output but also from the modularity of newer ones but I wont be able to buy one in the next few weeks or months. However as for my current PSU, I would like to know which is the safer choice for me to use for the 1070 in the short term.

1. 4-pin molex to 8-pin connector adapter + native 6-pin power connector

or

2. 6-pin to 8-pin connector adapter + native 6-pin power connector

or

3. two 6-pin to 8-pin connector adapter + 4-pin molex to 6-pin connector adapter

 

[buellersdayoff]

I am partly considering getting a new PSU aside from the power output but also from the modularity of newer ones but I wont be able to buy one in the next few weeks or months. However as for my current PSU, I would like to know which is the safer choice for me to use for the 1070 in the short term.

1. 4-pin molex to 8-pin connector adapter + native 6-pin power connector

or

2. 6-pin to 8-pin connector adapter + native 6-pin power connector

or

3. two 6-pin to 8-pin connector adapter + 4-pin molex to 6-pin connector adapter

Option 2, one 6pin and one 6pin to 8pin adapter, your power supply will be fine

 

[Battousai01]

Option 2, one 6pin and one 6pin to 8pin adapter, your power supply will be fine

Thanks! I but what is the difference between the two in terms of power delivery? And can I use the dual 6-pin to 8-pin as a replacement for the 6-pin to 8-pin? it seems that the wire configuration is the same.

1. 6-pin to 8-pin connector adapter

2. Dual 6-pin to 8-pin connector adapter

 

[buellersdayoff]

Thanks! I but what is the difference between the two in terms of power delivery? And can I use the dual 6-pin to 8-pin as a replacement for the 6-pin to 8-pin? it seems that the wire configuration is the same.

1. 6-pin to 8-pin connector adapter

2. Dual 6-pin to 8-pin connector adapter

Since you have only two 6pin connections from your power supply, option 1. is it. Power draw will be determined by GPU bios and whether you over clock. You just need to make sure that your power supply can provide enough, and it should.

 

[Wall Street]

If you use the dual 6-pin to 8-pin, make sure that your PSU doesn't have multiple 12 volt rails.

What I would do is first see if you can just plug the 6-pin into the 8-pin and get it to work. Sometimes on those card it will not actually sense if the other two pins are present. This is better than using any adapter.

Fallback option would be to use the single 6-pin to 8-pin adapter.

In terms of power delivery, the dual 6-pin to 8-pin should be better if your 6-pin connectors have very small gauge wire, but otherwise won't do much. If you use the dual 6-pin to 8-pin connector, what will you plug into the 6-pin socket?

The reason this PSU doesn't have an 8-pin connector is that the wattage is so low. You are right that your card doesn't need an 8-pin, but with the PSU, I would not overclock your CPU or raise the GPU power target.