# High VRM temp makes OC unstable



## mrthanhnguyen (Feb 20, 2020)

My z390 prime a vrm hits 90c during stress test while my cpu stays 70c-75c. Does it cause my oc unstable? I don't see any option to water cool it. Do put a vrm fan help or just buy a new mobo?


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## lexluthermiester (Feb 20, 2020)

mrthanhnguyen said:


> My z390 prime a vrm hits 90c during stress test while my cpu stays 70c-75c. Does it cause my oc unstable? I don't see any option to water cool it. Do put a vrm fan help or just buy a new mobo?


Those temps for VRMs are fine. Most VRMs, even the low quality ones, can withstand 130C nominal and 160C spikes without damage. However, mounting a heatsink/fan to them can't hurt.


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## Zach_01 (Feb 20, 2020)

First you spend 5~15$ for a fan over VRM, and if not work then spend, X10~20 the amount of fan money for a new board...


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## oxrufiioxo (Feb 20, 2020)

mrthanhnguyen said:


> My z390 prime a vrm hits 90c during stress test while my cpu stays 70c-75c. Does it cause my oc unstable? I don't see any option to water cool it. Do put a vrm fan help or just buy a new mobo?




Seems the board is just pretty meh vrm wise for a 9900k

4 phase with 8 45 amp power stages.  The Maximus Hero/Code/Formula all have pretty weak Vrms compared to other similarly priced high end boards as well.

Not sure about if that's enough to make your OC unstable but on boards with shittier vrms you sometimes need more vcore to keep a stable overclock on high wattage chips.

5.2ghz is pretty difficult even on a KS chip according to silicon lottery depending on the type of workloads you're running.

Also if you're not crashing I wouldn't worry about it unless you were hitting 110C under heavy load on the VRMs






						Historical Binning Statistics
					

Historical binning statistics from Silicon Lottery




					siliconlottery.com


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## joemama (Feb 20, 2020)

You really should have bought a better board for the 9900KS, but it is still fine to use this board as long as no problem occurs, though the service life of the board might be shorter.
You can put a fan to help cool it if you want


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## mrthanhnguyen (Feb 20, 2020)

I passed 8hr of realbench, 1hr occt large with avx , but fail occt linpack 2019 within 10m. Im so lazy to buy a new board coz I need to drain the whole loop then install 2tb games.


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## oxrufiioxo (Feb 20, 2020)

mrthanhnguyen said:


> I passed 8hr of realbench, 1hr occt large with avx , but fail occt linpack 2019 within 10m. Im so lazy to buy a new board coz I need to drain the whole loop then install 2tb games.



What are you primarily using your pc for?

Also are you stable at 5.1ghz in occt linpack 2019? You may just need an avx offset of like 2-300Mhz


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## mrthanhnguyen (Feb 20, 2020)

Stable 5.1 with linpack. I just game.


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## eidairaman1 (Feb 20, 2020)

Watch and interpret these.
VRM Tutorial by @buildzoid 








Asus Z390 Prime-A breakdown, also by @buildzoid 











mrthanhnguyen said:


> Stable 5.1 with linpack. I just game.


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## delshay (Feb 20, 2020)

Perhaps 17 W/mk thermal pads can help. Look to Fujipoly or Alphacool.


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## oxrufiioxo (Feb 20, 2020)

mrthanhnguyen said:


> Stable 5.1 with linpack. I just game.



Probably more your chip not liking 5.2 vs your vrm being an issue.


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## XL-R8R (Feb 20, 2020)

The difference between 5.1GHz and 5.2GHz for anything outside of benchmarking, is very minimal.



Save yourself the mental ache and be happy with your totally stable 5.1GHz and call it a day - unless you wish to shove ungodly amounts of voltage at the CPU or spend money on a new board and get to draining that loop and _*maybe*_ gaining 100MHz for your money/effort - keep what you have and smile.


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## JackCarver (Feb 20, 2020)

If it‘s only in Linpack and use case is gaming then there is no problem as you are stable during gameplay. What is the problem in Linpack, does CPU throttle or do you get blue screens or error messages? Usually most boards throttle down cpu if vrm gets too hot to avoid damaging vrm. If your cpu run Full Speed and Linpack fails it‘s rather a problem with too low voltage to get stable there. Also worth to take into account is that mosfets can‘t handle their max capable current over the whole temperature curve. The hotter they get the less capable they are with current load, so active cooling would rise their current capability. A rear fan intake lowers vrm temps up to 10C according to measurements.


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## EarthDog (Feb 20, 2020)

1. Those vrm temps are fine. Cooler is always better. Spot cool and/or replace thermal pads.
2. Why are you stress testing with multiple tests?? Passing two but not a third (which that third is overkill). Is your pc mission critical status? You say you just game so... pick a test, I like aida64 for my uses, and run a stress test for a few/several hours. If it passes, chances are you will be fine to simply game.

PS- love the passive aggressive lol emoji trolling in the first post...


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## xtreemchaos (Feb 20, 2020)

stick a small fan on it, my vrm is pants with fan it stops in the 70s on high load.
mines holded on with double sided tape.


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## FreedomEclipse (Feb 20, 2020)

Look for something like an Antec Spotcool


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## mrthanhnguyen (Feb 25, 2020)

I put a 120mm fan which run max speed and blow to those vrm area. Temp never has a chance to crack 65c. The problem is I think my pc is freaking loud.


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## eidairaman1 (Feb 25, 2020)

mrthanhnguyen said:


> I put a 120mm fan which run max speed and blow to those vrm area. Temp never has a chance to crack 65c. The problem is I think my pc is freaking loud.



Get water cooling or a potentiometer


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## mrthanhnguyen (Feb 25, 2020)

There is no monoblock option for my mobo.


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## eidairaman1 (Feb 25, 2020)

mrthanhnguyen said:


> There is no monoblock option for my mobo.





			vrm water blocks - Google Search
		







						Mosfet Blocks
					

EKWaterBlocks Shop offers you complete assortiment for water-cooling of your PC. Only EK and EK confirmed quality products.




					www.ekwb.com


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## mrthanhnguyen (Feb 25, 2020)

Which one fit my asus z390 prime a?


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## tabascosauz (Feb 25, 2020)

eidairaman1 said:


> vrm water blocks - Google Search
> 
> 
> 
> ...



We all appreciate your work, but you can't just throw lmgtfy at other people without yourself understanding an ounce of what you're actually suggesting. Those aren't monoblocks, and neither do any of those board-specific MOSFET blocks work on his board.

@mrthanhnguyen It's a 9900K @ 5.2GHz and your VRM isn't the greatest around (neither is it the worst). The only way to get around it is to have airflow over the heatsink, which you are already doing. Try and find a quieter fan, rearrange the airflow to work without the extra fan, or use fan control...you can't have everything at the same time.


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## eidairaman1 (Feb 25, 2020)

Ask EK, sometimes we have to adapt and overcome challenges that is why  ASepoxy mixed with as5 is a solution...


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## Taraquin (Feb 25, 2020)

mrthanhnguyen said:


> My z390 prime a vrm hits 90c during stress test while my cpu stays 70c-75c. Does it cause my oc unstable? I don't see any option to water cool it. Do put a vrm fan help or just buy a new mobo?


VRMs will be much cooler with a 5GHz clock vs 5.2GHz, you can lower voltage and consumption/heat will drop a lot. Performancewise there is very little difference in games. If you use a 240Hz monitor and game at medium settings fullHD with a mid range or better GPU then you might lose a few frames, but in most scenarios it won't make a diffetence.


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## Vayra86 (Feb 25, 2020)

mrthanhnguyen said:


> I passed 8hr of realbench, 1hr occt large with avx , but fail occt linpack 2019 within 10m. Im so lazy to buy a new board coz I need to drain the whole loop then install 2tb games.



Drop 100mhz and forget about it.

The board won't give you much more, so back down so you get assurance of a stable setup, and start gaming.


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## Schmuckley (Feb 25, 2020)

mrthanhnguyen said:


> My z390 prime a vrm hits 90c during stress test while my cpu stays 70c-75c. Does it cause my oc unstable? I don't see any option to water cool it. Do put a vrm fan help or just buy a new mobo?


You should put a fan onto your vrm sink, at least a Cooler Master-type.


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## mrthanhnguyen (Mar 4, 2020)

Its weird guys. Borrow a 9900ks from a friend and its stable 8hr prime95 5.2ghz at 1.3v on evga dark. Put that chip to my board and it crashes 5s after hit start prime95.


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## oxrufiioxo (Mar 4, 2020)

mrthanhnguyen said:


> Its weird guys. Borrow a 9900ks from a friend and its stable 8hr prime95 5.2ghz at 1.3v on evga dark. Put that chip to my board and it crashes 5s after hit start prime95.




The Dark is a substantially better board that probably has a way more stable voltages.

Either way a 400 board isn't worth 100mhz.


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## JackCarver (Mar 4, 2020)

Not weird, the Dark has better vrm. 6 real phases on the Dark vs 4 real phases on your board can make the difference as ripple is higher on your board compared to the Dark.


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## mrthanhnguyen (Mar 4, 2020)

Dark or apex or aorus master? I have money yo throw out.


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## JackCarver (Mar 4, 2020)

mrthanhnguyen said:


> Dark or apex or aorus master?



VRM wise the Apex is best, 8 real phases and IR power stages.
VRMs of Dark and Master are very similar, 6 real phases and Doublers used, but as you had good results with the Dark from your friend, I would choose the Dark, if I had to choose between the two.



mrthanhnguyen said:


> I have money yo throw out.


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## mrthanhnguyen (Mar 4, 2020)

If vrm on aorus master and the dark are the same, I may try the master because it has 4 ram slots. The dark and apex have only 2 slots. I have 4 sticks of ram.


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## oxrufiioxo (Mar 4, 2020)

mrthanhnguyen said:


> If vrm on aorus master and the dark are the same, I may try the master because it has 4 ram slots. The dark and apex have only 2 slots. I have 4 sticks of ram.




The Dark has a better vrm and a way better pcb than the master.


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## JackCarver (Mar 4, 2020)

mrthanhnguyen said:


> If vrm on aorus master and the dark are the same, I may try the master because it has 4 ram slots. The dark and apex have only 2 slots. I have 4 sticks of ram.



Not exact the same, they both have 6 real phases and both use doublers to get up to 12 virtual vcore phases. The Master has 40A power stages whereas the Dark uses 60A stages, so the Dark is capable of handling more current than the Master. Question is if the 12x40A=480A power stages of the Master are sufficient and I would say yes cause you also have to cool this huge load. Both have really big heatsinks on top of the vrm, the Dark heatsink seems to be even a little bigger here. But with the Dark you theoretically would have to cool 12x60A=720A max current load.

But as you said, that you had good results with the Dark, I would also choose this one like @oxrufiioxo said.


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## mrthanhnguyen (Mar 4, 2020)

Have a very good deal of apex. Is dark much better than apex?


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## JackCarver (Mar 4, 2020)

mrthanhnguyen said:


> Have a very good deal of apex. Is dark much better than apex?



Apex is better, 8 real phases for vcore in twin configuration, so 16 IR power stages, capable of 60A each power stage, so theoretically 16x60A=960A max current load.
Also the ripple effect is less here as it has 8 real phases compared to Dark or Master which have only 6 real phases.

Edit:
I think it's a very good OC mainboard, but also look at the other specs if it's suitable for you.


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## oxrufiioxo (Mar 4, 2020)

JackCarver said:


> Apex is better, 8 real phases for vcore in twin configuration, so 16 IR power stages, capable of 60A each power stage, so theoretically 16x60A=960A max current load.
> Also the ripple effect is less here as it has 8 real phases compared to Dark or Master which have only 6 real phases.




The Apex probably has slightly better transient response as well. I still think the actual pcb of the Dark is better though.... Again though whether its 300 or 500 in your local currency that is a high price to pay for an extra 100mhz.


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## JackCarver (Mar 4, 2020)

oxrufiioxo said:


> The Apex probably has slightly better transient response as well....



Yes without Doublers transient response may be also better here. It's a nice OC mainboard, but I didn't look at the other specs of the board like USB/sound and so on.


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## oxrufiioxo (Mar 4, 2020)

I would make sure to watch both these vids before deciding on either. If you haven't already. The output filtering on the Dark is insane.


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## EarthDog (Mar 4, 2020)

oxrufiioxo said:


> The output filtering on the Dark is insane.


While that is true, living in this level of minutia for ambient overclocks is a waste of time. For all intents and purposes, all three boards listed will bring this CPU to the same overclock.... in other words, the seeming hard wall limits these CPUs have.


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## oxrufiioxo (Mar 4, 2020)

EarthDog said:


> While that is true, living in this level of minutia for ambient overclocks is a waste of time. For all intents and purposes, all three boards listed will bring this CPU to the same overclock.... in other words, the seeming hard wall limits these CPUs have.




I agree, but if you're ditching a completely viable board for 5.1ghz you might as well get the best and not worry about it anymore..... I have my doubts that his specific cpu will clock any higher in either of these boards but I would be happy to be wrong.


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## JackCarver (Mar 4, 2020)

EarthDog said:


> While that is true, living in this level of minutia for ambient overclocks



The Apex is designed for LN2 OC. It has sensors to detect condensate


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## EarthDog (Mar 4, 2020)

JackCarver said:


> The Apex is designed for LN2 OC. It has sensors to detect condensate


Well aware.... just saying that this level of minutia isn't terribly helpful. 


oxrufiioxo said:


> I agree, but if you're ditching a completely viable board for 5.1ghz you might as well get the best and not worry about it anymore..... I have my doubts that his specific cpu will clock any higher in either of these boards but I would be happy to be wrong.


The choice is his/hers, surely... just saying for ambient overclocking, it won't make a difference.


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## mrthanhnguyen (Mar 7, 2020)

5.2ghz at 1.3v now on the apex. It was 1.36v for 5.2ghz on the prime a. Still fail occt linpack but seem pass realbench 1hr so far. Maybe I need to increase vcore a little bit to be stable in linpack.


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## JackCarver (Mar 7, 2020)

mrthanhnguyen said:


> 5.2ghz at 1.3v now on the apex. It was 1.36v for 5.2ghz on the prime a. Still fail occt linpack but seem pass realbench 1hr so far. Maybe I need to increase vcore a little bit to be stable in linpack.



Nice one. Also impressive that you get the same results with 0.06 less VCore. That‘s the ripple effect which is way better on an 8 phase board compared to your 4 phase board before. Yes I assume with a little more VCore you get stable in Linpack.


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## mrthanhnguyen (Mar 7, 2020)

1.3v in bios llc6, but why hwinfo and cpuz show only 1.243 during load? This board has llc up to 8 while the old board has only 7 and I chose  6.If I choose 6 in this apex, does this mean 5 in the prime?


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## JackCarver (Mar 7, 2020)

mrthanhnguyen said:


> 1.3v in bios llc6, but why hwinfo and cpuz show only 1.243 during load? This board has llc up to 8 while the old board has only 7 and I chose  6.If I choose 6 in this apex, does this mean 5 in the prime?
> 
> 
> View attachment 147406



That‘s the loadline as intended by Intel. You set a voltage in BIOS and usually you have a slightly drop of this voltage in windows idle which is called vdrop. When you switch from idle to load you have another voltage drop which is called vdroop. This is intended because of the transient response effect. There should always be a drop from idle to load. With llc you can compensate this drop if you get unstable under load. So you can choose various llc level in BIOS and see how vdroop changes. For high oc it‘s often recommended to choose a llc level where there is no vdroop at all, so voltage in idle is the same as voltage under load but that‘s not good for the cpu. Better is choosing an llc level with vdroop, so that voltage under load is less than voltage in idle. But you can try different llc level in BIOS and test in windows.


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## mrthanhnguyen (Mar 7, 2020)

I feel weird because with the prime a mobo, load voltage is always higher than idle. For example, 1,36v in bios  and llc6 and it will be 1.376v during load. This apex llc7, 1.25v in bios , 1.243 idle and 1.204v during load.


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## JackCarver (Mar 8, 2020)

mrthanhnguyen said:


> I feel weird because with the prime a mobo, load voltage is always higher than idle. For example, 1,36v in bios  and llc6 and it will be 1.376v during load. This apex llc7, 1.25v in bios , 1.243 idle and 1.204v during load.



That‘s dependent of the loadline level. I‘m sure there are also loadline levels on the prime where voltage under load is less than voltage in idle. 
You can also choose different loadline levels on the apex with different idle/load voltage behaviour from llc1 to llc7.


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## oxrufiioxo (Mar 8, 2020)

You'll have to experiment unless somebody else has a z390 Apex and a 9900k for you to compare with.


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## mrthanhnguyen (Mar 8, 2020)

The voltage with misleading you for. But how the vdroop does not make the temp lower? 1.28v in bios and at load vcore only 1.245 but temp is the same as I use 1.36v on the prime.


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## oxrufiioxo (Mar 8, 2020)

mrthanhnguyen said:


> The voltage with misleading you for. But how the vdroop does not make the temp lower? 1.28v in bios and at load vcore only 1.245 but temp is the same as I use 1.36v on the prime.




Software voltage readings can be inaccurate... so like I said you need to experiment.


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## JackCarver (Mar 8, 2020)

mrthanhnguyen said:


> The voltage with misleading you for. But how the vdroop does not make the temp lower? 1.28v in bios and at load vcore only 1.245 but temp is the same as I use 1.36v on the prime.



Heat comes from the power loss of a cpu which is dissipated as heat, so you would have to compare the power the cpu draws at the prime and at the apex, not only the VCore.

The ripple effect is also a factor to take into consideration. You need less VCore at the apex to get stable under load compared to the prime as the vrm is more efficient at the apex. But the power the cpu draws is the same.


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## Vayra86 (Mar 8, 2020)

EarthDog said:


> While that is true, living in this level of minutia for ambient overclocks is a waste of time. For all intents and purposes, all three boards listed will bring this CPU to the same overclock.... in other words, the seeming hard wall limits these CPUs have.



This. Don't buy into the marketing unless you are gunning for record scores. And when you do buy in, go all the way or its a waste of time anyway.


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## lp_985 (Feb 5, 2021)

Whats up guys little bit late but that all right i guess.Here is my DIY VRM s cooling solution with X TRIO FANS.Smaller one an smaller rad and bigger one on bigger rad.They are cold as ice.

I9900 KS 5.3 no problem for gaming
Aourus Master Z390


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## oxrufiioxo (Feb 5, 2021)

lp_985 said:


> Whats up guys little bit late but that all right i guess.Here is my DIY VRM s cooling solution with X TRIO FANS.Smaller one an smaller rad and bigger one on bigger rad.They are cold as ice.
> 
> I9900 KS 5.3 no problem for gaming
> Aourus Master Z390




Ummm.... So you strapped fans to a vrm that doesn't need cooling........ Seems legit.


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## lp_985 (Feb 5, 2021)

DIY is prety understandable word right?I know they don t need cooling,still temps are now way better


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## oxrufiioxo (Feb 5, 2021)

lp_985 said:


> DIY is prety understandable word right?I know they don t need cooling,still temps are now way better



Definitely..... I had to do a couple double takes on your PC... Removing the shroud on the gpu as well and using 120mm fans to cool it is interesting to say the least..... Maybe you should go into WC it will look a lot better and the temps will be even lower since you seem to love the dyi stuff.


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## lp_985 (Feb 5, 2021)

oxrufiioxo said:


> Definitely..... I had to do a couple double takes on your PC... Removing the shroud on the gpu as well and using 120mm fans to cool it is interesting to say the least..... Maybe you should go into WC it will look a lot better and the temps will be even lower since you seem to love the dyi stuff.


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## mouacyk (Mar 31, 2021)

lp_985 said:


> Whats up guys little bit late but that all right i guess.Here is my DIY VRM s cooling solution with X TRIO FANS.Smaller one an smaller rad and bigger one on bigger rad.They are cold as ice.
> 
> I9900 KS 5.3 no problem for gaming
> Aourus Master Z390


Are you Optimus Prime -- snacking on nuts and bolts, then washing them down with oil (the bottle)? Gratz on 5.3GHz.


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## Zach_01 (Mar 31, 2021)

Are we talking about thermaltake or thermalgive? Depends...


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