# pcie power output



## specks (Mar 20, 2011)

What is the max power(watts) output of an pcie 1.0 x16 slot?


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## CDdude55 (Mar 20, 2011)

75w if i remember correctly.


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## Athlon2K15 (Mar 20, 2011)

+1


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## cadaveca (Mar 20, 2011)

PCI-E 1.0 is 60w.



> A standard height x16 add-in card intended for graphics
> applications must, at initial power-up, not exceed 25 W of power dissipation, until
> configured as a high power device, at which time it must not exceed 60 W of power
> dissipation.




Devices draw power from 12v and 3.3v, and cannot exceed 75w between the two.


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## specks (Mar 20, 2011)

how about for pcie 2.0 x16?


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## cadaveca (Mar 20, 2011)

specks said:


> how about for pcie 2.0 x16?



Same thing, as far as I know, added 8-pin for high-power spec(where the actual power increase comes from) and the speed increase. There's something about PCI-E cabling(for server-type stuff), the automatic speed and link-width dynamic chages for power saving, and other such stuff unrelated to this conversation.


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## specks (Mar 21, 2011)

So does this mean that slot powered gpu's like(my)hd4670 can only draw a max of 60watts from the pcie slot?


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## Mussels (Mar 21, 2011)

specks said:


> So does this mean that slot powered gpu's like(my)hd4670 can only draw a max of 60watts from the pcie slot?



no, its 75W from the slot, some being 3.3V and some being 12V. thats the most any PCI-E card can use, graphics or not.


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## specks (Mar 21, 2011)

So still, it cannot consume more than 75 watts from the slot alone?


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## Mussels (Mar 21, 2011)

specks said:


> So still, it cannot consume more than 75 watts from the slot alone?



it CAN, but not at default settings. if you overclock it can use more than that, for example.


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## specks (Mar 21, 2011)

So say if the card is under load(overclocked or not)and it should be able to consume for example 100watts then can the slot give out 100watts?


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## Mussels (Mar 21, 2011)

specks said:


> So say if the card is under load(overclocked or not)and it should be able to consume for example 100watts then can the slot give out 100watts?



no. no card would ever be sold that breaches the 75W limit from the slot. this is why most cards have external power.


if it went over that 75W limit, things could get screwy. wiring overheating, voltage drops to other devices powered from the mobo, etc. there is a hard limit that all PCI-E devices must adhere to.


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## specks (Mar 21, 2011)

In this case, the card can only use 75watts under normal clocks and more power if overclocked?

Are the power outputs of pcie 1.0, 1.1, 2.0 and 2.1 still 75watts?


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## Mussels (Mar 21, 2011)

specks said:


> In this case, the card can only use 75watts under normal clocks and more power if overclocked?



Yes, but things can go wrong if you do so.




specks said:


> Are the power outputs of pcie 1.0, 1.1, 2.0 and 2.1 still 75watts?



no. as the standards go up, they boosted the power via the external cables.


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## specks (Mar 21, 2011)

Mussels said:


> Yes, but things can go wrong if you do so.
> 
> 
> 
> ...



Mine is overclocked and all is fine. 

What i mean is the max power of the slots alone disregarding the external power cables. Do you know what is the max of the pcie 2.0 x16?


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## slyfox2151 (Mar 21, 2011)

specks said:


> Mine is overclocked and all is fine.
> 
> What i mean is the max power of the slots alone disregarding the external power cables. Do you know what is the max of the pcie 2.0 x16?



its 75watts (from the slot itself. a combination of 60 watts from 12volt and 15watts from 3.3volt according to cadavas post) as has already been said MANY times.....

yes im sure you can pull more then 75 watts out of the slot if you tried too, however im sure bad things will start to happen at some point. 


there has been threads on here with people showing Burnt ATX 24pin power cables from pulling too much power from multiple PCI-E slots.



EDIT:
http://www.pcisig.com/developers/ma...c_id=b590ba08170074a537626a7a601aa04b52bc3fec

Page 39 and 41 should give you some clear numbers of what PCI-E can provide power wise. 

link borrow from Mussels


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## 95Viper (Mar 21, 2011)

A little light reading, look at layout pages 10, 11, 12, and 13 for answer to your question.

PDF here and zip file download of PCI Sig's PCI Express 1.1 Mechanical Form Factors.


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## Mussels (Mar 21, 2011)

specks said:


> Mine is overclocked and all is fine.
> 
> What i mean is the max power of the slots alone disregarding the external power cables. Do you know what is the max of the pcie 2.0 x16?



its been said many times. 75W for slot, rest from external cables only. as the standards went up the slot power did not change.


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## cadaveca (Mar 21, 2011)

It is possible to push 150w out of one PCI-E slot, on some motherboards. Some can push 300w over 4 slots, however, most often, these boards feature an additional power plug just for the slots.


Many board, however, that come out long ago, cannot even supply enough power over PCIe for 3x VGA....we had guys modding extra wires from PSU, as multiple cards would blow the 24-pin. Also, you'll find the new ASUS Black X58 board features MANY ways to add power to PCIe slots.


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## newtekie1 (Mar 21, 2011)

Mussels said:


> no card would ever be sold that breaches the 75W limit from the slot.



Thats not true, W1z reviewed one a while ago that did exactly that.  I think it was a GT240 that pulled something like 85w maximum through just the slot.  I also believe a lot of those G92/G94 based "Green Edition" cards exceeded the PCI-E spec as well.

The standard for 1.1 and 2.0 are both 75w, but the slot will really give whatever is asked of it.  However, going over the 75w can lead to some pretty nasty things.


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## specks (Mar 21, 2011)

slyfox2151 said:


> its 75watts (from the slot itself. a combination of 60 watts from 12volt and 15watts from 3.3volt according to cadavas post) as has already been said MANY times.....
> 
> yes im sure you can pull more then 75 watts out of the slot if you tried too, however im sure bad things will start to happen at some point.
> 
> ...



I would appreciate it if you can give me a link to those burnt atx power cables. i'm just curious

Anyways, thanks to all for clearing things for me!


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## cadaveca (Mar 22, 2011)

the 24-pin issue was such a large one that EVGA developed a plug you could put into PCIe slot directly, even.

See more here:

http://www.evga.com/forums/tm.aspx?m=749507&mpage=1&print=true


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