VRM water block.... uneffective?

[bluezero5]

I recently installed a Waterblock for the VRM mosfets.

I was expecting the temps to drop a lot.

but on the first test on clocking with 1.52V, the VRM still throttles the CPU.

lucky is that if I point a fan at the Mobo northbridge, it solves the throttling....
but anyone know why watercooling the mosfet is not effective?

I checked that I didn't do anything stupid.. (like forgetting thermal pads etc)

Just am majorly disappointed at an investment that has no value. (ended up pointing a fan at it.. again.


any insights on how to cool the VRM better?


please share your experiences.

[ugapug]

Mine idles at 30*C and goes to 45*C with the EK water block.
Check to make sure the thermal pads are making contact.

[Arne Saknussemm]

Typical thermal pad removes heat at around 3w/m-k around a third of a typical thermal paste which is not great for cooling. The pads only sit across the top of the VRM and conduct to the block. I would not expect miracles from it. Air, however bad at cooling, at least gets in and around the VRM and if you blow enough of it with a decent fan will probably cool as well or even better. Both together even better!

[Raja@ASUS]

The FETs on the back of the board are generally the limiting factor.

[Zka17]

I recently installed a Waterblock for the VRM mosfets.

I was expecting the temps to drop a lot.

but on the first test on clocking with 1.52V, the VRM still throttles the CPU.

lucky is that if I point a fan at the Mobo northbridge, it solves the throttling....
but anyone know why watercooling the mosfet is not effective?

I checked that I didn't do anything stupid.. (like forgetting thermal pads etc)

Just am majorly disappointed at an investment that has no value. (ended up pointing a fan at it.. again.


any insights on how to cool the VRM better?


please share your experiences.

bluezero5, could you, please, describe in detail you watercooling loop? I'm specially interested in the direction of the coolant flow...

Something is not right in your build... The watercooling supposed to be more effective that the air one... Oh, and one more thing! Could you also describe the airflow through your case and radiators?

[8 Pack]

I use the EK block with any Vcore upto 1.68 for benching and never see throttling. Something is definitely not right here. Have you tried a remount and at the same time check your contact is good. I also use RAM sinks on the back of the board to help remove the heat from those fets. As Raja points out they can also be a limiting factor.

[bluezero5]

IMG_3764.JPGIMG_3760.JPG

there it is.

airflow I have fan in front/side/bottom blowing in.
top and back radiator radiates out.

water goes:

Res->pump->120.2 top rad->cpu->120.1 back rad->VRM ->SouthBridge block -> bottom 120.2 rad -> GPU -> res.


man it will be a pain to dismount the thing with tubes attached...
but I guess I hafta huh?

yes, I realize there are back fets too, right now using the original thermal pads.
are there BETTER thermal pads out there?

and should I ADD thermal paste with the pads?

insights welcomed.

[Zka17]

airflow I have fan in front/side/bottom blowing in.
top and back radiator radiates out.

water goes:

Res->pump->120.2 top rad->cpu->120.1 back rad->VRM ->SouthBridge block -> bottom 120.2 rad -> GPU -> res.

Thanks bluezero5 for the details!

Allow me to point out something to you: You're running a 3930K CPU on 1.52V Vcore - that's meaning that it's getting really hot! Now, you'r saying that your temps are fine ("not even above 70C")... but imagine, where all the heat produced by CPU is going... into the water - right? That rear single 120 mm radiator would barely dissipate all the heat produced by a 3930k at 1.52V Vcore... Which is meaning that your are sending preheated water on the VRM! So the VRM is still not cooled effectively...

Without dismounting the tubes, you have basically two choices: reduce the voltages (Intel's safe specs are 1.4V) and/or increase the heat dissipation on that rear radiator. The first option is up to you... certainly would reduce the heat production, but if you like those high voltages... For the second option, you could modify the overall airflow by adjusting the fan speeds, those forcing more air through the rear radiator.

[8 Pack]

Thanks bluezero5 for the details!

Allow me to point out something to you: You're running a 3930K CPU on 1.52V Vcore - that's meaning that it's getting really hot! Now, you'r saying that your temps are fine ("not even above 70C")... but imagine, where all the heat produced by CPU is going... into the water - right? That rear single 120 mm radiator would barely dissipate all the heat produced by a 3930k at 1.52V Vcore... Which is meaning that your are sending preheated water on the VRM! So the VRM is still not cooled effectively...

Without dismounting the tubes, you have basically two choices: reduce the voltages (Intel's safe specs are 1.4V) and/or increase the heat dissipation on that rear radiator. The first option is up to you... certainly would reduce the heat production, but if you like those high voltages... For the second option, you could modify the overall airflow by adjusting the fan speeds, those forcing more air through the rear radiator.

#

Spot on mate!!! I agree My VRM is actually first in my loop and gets 14C water from a chiller.

[ugotd8]

I also use RAM sinks on the back of the board to help remove the heat from those fets. As Raja points out they can also be a limiting factor.

So you have heatsinks directly attached to the backplate that covers those FETs or did you do something different ?