What happens if my GPU uses more than 75W???

Hamilton_1

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Jan 10, 2014
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So, I'm just starting to experiment with overclocking and I've seen that my graphics card can draw a maximum of 75W power

Would I give any serious damage to the graphics card by going over 75W???
How will I know if I've gone over (will the computer shutdown to protect it)???

Any help/advice would be appreciated

Thank you
 
Solution
What graphics card? Im assuming its a gpu that just plugs into the motherboard and there are no 6pin or 8pin power connectors going from the psu to the card. The pcie x16 2.0 slot on your motherbaord can only provide 75watts of power to the card if you overclock too high it might try to use more than 75watts and if it does it could crash this shouldn't damage anything just turn down the overclock if it crashes.
75 watts is the rated power limit of the PCI-E slot. This is augmented by power cables which are used when cards use more power..... 6 pin cables can carry 75 watts .... 8 pin cables can carry 150 watts.

While there's undoubtedly a little leeway / conservatism in there, at some point you will reach a limit and I couldn't guess where that would be. That oft can make your decision for you when picking a GFX card that might be under equipped cable connector wise when overclocking

I have pulled 1.12 amps from a 1.0 amp rated MoBo header on several builds 12% over spec) w/o issue..... each was a high end MBo..... I'd be more hesitant with a cheaper board. If you're pulling 77 or 80 watts, I wouldn't worry.... If your pulling 90, I'd be nervous.

 
The PCIe slot that your video card sits in can only provide 75w.

Most video cards also have an additional power cable or two coming from the power supply which can provide as much as 300w more power. There are two types of cables that can come from the power supply. The first is a 6 pin connector, which provides 75w. The 6 pin connector can actually use an 8 pin connector which leaves 2 pins over-hanging the end of the 6 pin connector. If you look closely, you will see that each 8 pin connector has 6 pins that are a solid piece, and then 2 pins that can flex outward on one end or the other. Those 8 pin connectors provide 150w when all 8 pins are in the 8 pin socket, or 75w when only 6 pins are in a 6 pin socket.

If a video card has power plugs on it that needs cables from the power supply, most of the time they will say something during bootup on the screen, and then stop the boot process until you connect the proper power cables.

Now, if your card has no power cables, and you over-clock it to where it needs more than 75w, then your video card and possibly your motherboard will either:

1) Power itself down
2) Shut the system down
3) Become unstable, eventually crashing the system.
4) Some unpredictable scenario that could damage hardware.

Bottom line? I would not over clock a video card that did not have power cables attached to it.
 

Dunlop0078

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What graphics card? Im assuming its a gpu that just plugs into the motherboard and there are no 6pin or 8pin power connectors going from the psu to the card. The pcie x16 2.0 slot on your motherbaord can only provide 75watts of power to the card if you overclock too high it might try to use more than 75watts and if it does it could crash this shouldn't damage anything just turn down the overclock if it crashes.
 
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Hamilton_1

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Jan 10, 2014
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msi nvidia gtx 750 ti 2gb oc
http://uk.msi.com/product/vga/N750Ti-2GD5OC.html#hero-overview

I realise that it's been overclocked already but I just wanted to be able to maximise its potential
 

Dunlop0078

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You should probably just leave it alone it has a pretty high boost speed. You probably wont get much performance out of the small overclock you would be able to do on that card. But if you should decide you want to try it here is a decent video on overclocking a gpu.

https://www.youtube.com/watch?v=ltGKeOyDKA8
 
The peak power consumption (Crysis 2 at 1920x1080, Extreme profile, representing a typical gaming power draw. Highest single reading during the test.) of the MSI 750 Ti is just 65 watts .... go ahead and do what you will.

power_peak.gif


You can go higher with Furmark, so just be aware that if you play with that while OC'd, you will exceed 75 watts if you take it further.
 
More here:

http://www.guru3d.com/articles_pages/msi_geforce_gtx_750_and_750_ti_gaming_review,5.html

Measured power consumption [MSI] GTX 750 Ti card

System in IDLE = 119 W
System Wattage with GPU in FULL Stress = 201W
Difference (GPU load) = 82W
Add average IDLE wattage ~10W
Subjective obtained GPU power consumption = ~92 Watts


That is at the wall .... so DC power output wise, we have to factor in PSU efficiency and for that low a load I'll figure 85% which puts you at 78 watts output