No heat at all from gpu by removing cables?

[Shadowman]

Since I have a custom water cooled PC thought best to post here. Basically am currently water cooling my cpu and gpu but my question was (sorry will sound silly) I want to leave the gpu in the water loop but if I remove the power cables for the gpu that would mean no power going to the gpu will that obviously mean there should be no heat coming from the gpu? I mean even on idle am sure the gpu is giving out heat?  It's because  I want to just test my cpu under full load and without the gpu in the loop and see the temps (I have a old air cooled gpu which I will use to run the test)

[Tristerin]

Just now, Shadowman said:

Since I have a custom water cooled PC thought best to post here. Basically am currently water cooling my cpu and gpu but my question was (sorry will sound silly) if I remove the power cables for the gpu that would mean no power going to the gpu will that obviously mean there should be no heat coming from the gpu? I mean even on idle am sure the you is giving out heat?  It's because  I want to just test my cpu under full load and without a gpu in the and see the temps (I have a old air cooled gpu which I will use to run the test)

Your GPU will still receive up to 75w from the PCIe slot itself, specifically to display something.  If you remove the cables and set BIOS to the iGPU and use just the CPU to display then I don't think it will power the GPU.  

[Shadowman]

5 minutes ago, Tristerin said:

Your GPU will still receive up to 75w from the PCIe slot itself, specifically to display something.  If you remove the cables and set BIOS to the iGPU and use just the CPU to display then I don't think it will power the GPU.  

Thanks, sorry forgot to mention my motherboard is a x299 no iGPU on there but have a old gpu will use that. My current gpu is the rtx 2080ti but will the PCIe slot be able to power it up without the PCIe cables plugged in? 

[Tristerin]

Just now, Shadowman said:

Thanks, sorry forgot to mention my motherboard is a x299 no GPU on there but have a old gpu will use that. My current gpu is the rtx 2080ti but will the PCIe slow be able to power it up without the PCIe cables plugged in? 

So no iGPU, but have an old GPU to just use as a display in a diff PCIe slot?  I don't see why this would be an issue.  It wont be able to render 3d but it will be able to power the 2d desktop no problem at all.

[Shadowman]

1 minute ago, Tristerin said:

So no iGPU, but have an old GPU to just use as a display in a diff PCIe slot?  I don't see why this would be an issue.  It wont be able to render 3d but it will be able to power the 2d desktop no problem at all.

I think there is a option on the motherboard to disable pcie slots? It's just I don't want any power going into the gpu which would mean no heat would be coming from it.

[Tristerin]

3 minutes ago, Shadowman said:

I think there is a option on the motherboard to disable pcie slots? It's just I don't want any power going into the gpu which would mean no heat would be coming from it.

Maybe your mobo has that option, Im unaware (nor have I tried to ever do this) - try it, and use HWMonitor to see if anything is detecting that GPU

[m0k]

if its not hard tubrng, then just take the GPU out of the the pcie slot and let it sit there. that way you will know for sure its not doing anything. 

 

that way you dont have to disassemble the loop and you wont mix gpu temps into the loop

[Shadowman]

Just now, mok said:

if its not hard tubring, then just take the GPU out of the the pcie slot and let it sit there. that way you will know for sure its not doing anything. 

 

that way you dont have to disassemble the loop and you wont mix gpu temps into the loop

Yes it is hard tubing. 

[mariushm]

ANY card will receive power through the pci-e slot.

 

Most video cards will start up without any additional pci-e power connectors but in a "reduced" mode, just to display a text that says something like "please turn off your pc and insert the power cables into the video card".

 

It's designed like that to prevent people from returning perfectly good hardware or sending it to warranty for not showing anything on monitor, because they forgot to insert the required extra power connectors. 

 

[Shadowman]

6 minutes ago, mariushm said:

ANY card will receive power through the pci-e slot.

 

Most video cards will start up without any additional pci-e power connectors but in a "reduced" mode, just to display a text that says something like "please turn off your pc and insert the power cables into the video card".

 

It's designed like that to prevent people from returning perfectly good hardware or sending it to warranty for not showing anything on monitor, because they forgot to insert the required extra power connectors. 

 

But would disabling the pcie slot that has the gpu in it via the motherboard send any power?

[mariushm]

Yeah, the slot will still receive power.

There's 3.3v aux (kind of like stand-by power) , 3.3v ( up to 10w, incl the 3.3v aux)  and 12v (up to around 65w)

 

There's usually no power switches on each pci-e slot to turn off power.

I think what the bios says by disabling pci-e slots is more or less that it won't query the device in the slot to ask what it is (if it's video card or something else), and it won't send it the command to initialize and all that, and it won't tell the operating system that there's something plugged into the slot). Whatever is inserted into the slot is just waiting for the bios to say "hello" and exchange information that's needed for the card to initialize.

So the card will still get power from the pci-e no matter what but until it's "initialized" it may only use a very small amount of energy, only what it gets from 3.3v for example.