Only 4 pins on an 8 pin gpu?

[Vod]

Hello!

I was wondering what would happen if I just filled out 4 our of 8 pins on an gpu.

And what whould happen if the psu was below the recomended wattage of the gpu.

Just answer for any scenario.

[minibois]

There is no 4 pin connector that will fit in your GPU.

If you are trying to plug in a 4 pin EPS connector to your GPU's 6+2 pin PCIE, nothing will happen because it's keyed so you can't do that.

 

if you try plugging in a 6 pin PCIE into a 6+2 pin PCIE slot, it will fit and the GPU may boot up (can't guarantee though), but it will likely crash once you put some serious load on it.

[corrado33]

The computer likely won't boot if you only use 4 of the 8 pins.

 

Some GPUs will display a little screen that says "Please plug in power cable and restart."

 

Using an underpowered PSU may result in crashes at high usage (gaming, etc.)

[Enderman]

First of all there is no 4 pin PCIe power connector.

If you're talking about a 4 pin EPS connector, it would kill the GPU, if you even managed to plug it in since usually the housing is different.

 

If your PSU is not enough wattage then your computer will shut off under load and there's a high risk of your PSU lighting on fire and burning your house down.

[Lurick]

12 minutes ago, Enderman said:

First of all there is no 8 pin PCIe power connector.

wat?

My 8-pin PCIe power cables say otherwise =/

 

Edit:

Unless you mean no "8-pin" because not all the pins are actually used?

[corrado33]

12 minutes ago, Enderman said:

First of all there is no 8 pin PCIe power connector.

If you're talking about a 4 pin EPS connector, it would kill the GPU, if you even managed to plug it in since usually the housing is different.

 

If your PSU is not enough wattage then your computer will shut off under load and there's a high risk of your PSU lighting on fire and burning your house down.

So, story time. I bought a used computer that came with some extra modular power cables. The used computer did not have a GPU, so I put mine in, and grabbed the extra modular power cable that had an 8 pin on the output side. I don't know how... exactly, but somehow it fit in the GPU power slot. (Was it a mistake on the cable? I dunno. I 100% didn't force it in.)

 

Anyway, the only difference between an EPS 8 pin and a PCIe 8 pin is 1 cable. On the EPS 4 pins are 12V and 4 pins are ground. On the PCIe, 3 pins are 12V and 5 pins are ground.

 

So essentially, you're shorting the 12V to ground. 

 

LUCKILY, most modern PSUs will NOT turn on if it detects a short (try it sometime). And the GPU doesn't get fried because it's shorted literally right at the cable. 

 

Also, most modern PSUs will immediately turn off it it detects a short. Try it sometime. Take an extra molex and cut the connector off, then touch the red or yellow wire to the case. The PSU will IMMEDIATELY shut down with no damage. 

 

How do I know this? I've done it before. I used to have no money so I modded a molex connector into a sata power connector and before I soldered the sata connector on I started the computer up to test and make sure the molex cable with ok. Well I... uh... lost control of the 12V wire and it touched the case (which is grounded) and everything shut down instantly. Then once I rectified the situation, everything started up just fine.

[Enderman]

3 minutes ago, Lurick said:

wat?

My 8-pin PCIe power cables say otherwise =/

typo, 4*

[Vod]

I have an really bad psu, and I have to make an upgrade on the gpu I bought on black Friday, and I still need to save up a little more for an 550w psu. 

 

And I didn't know what what going to happen, the first thing I thought was that it was going to ruin the gpu so I came here to ask

[Mick Naughty]

Should be good, plug it in and turn it on.