Air-cooling outperforming water-cooling, help.

[CSR1978]

I have two almost identical computers running with the same motherboard (Gigabyte z390 Master), same CPU (i9-9900k), same RAM (Corsair Vergence 32gb), same SSD (Samsung 970+ 1TB), same power supply (Corsair 800w) and same OS (Windows 10 pro).

 

The only difference between the two is that one resides in a standard, metal Corsair atx case and uses a beQuiet air cooler, and the other is in a Thermaltake open case design with a custom water cooler.

 

The water cooler uses all Thermaltake components (copper CPU block, copper 64mm thick x 480mm tall radiator with 8 fans in push pull design, and pump). It only cools the CPU.

The problem is that the air cooled system runs at full load significantly cooler than the water cooled system. Both are overclocked with the exact same settings (all cores to 4.7ghz). Both are stable. However, the air cooled temperatures peak at high 80 deg C and the water cooled peaks at 110 deg C running any type of benchmark (geekbench and timespy specifically).

 

Why is the air cooled system outperforming the water cooled system? Ultimately, this results in me being able to overclock the air cooled system to 5.1ghz, stable.

 

I've already tried reseating and repasting the water block. I very diligently flushed the radiator before installation as well as ran a pre coolant cleaning solution for 12 hours. So hopefully there is no debris stuck in the water block. The pump is running, water is flowing. The pipes warm up, so I know it's drawing heat from the CPU. The radiator fans are all blowing with nothing obstructing the air flow.

 

Did I just get unlucky with the CPU lottery? Does the CPU assembly line have a bigger effect than cooling system choice? Is the $800+ of water cooling parts a waste or a joke?

Please help with any input or suggestions. Thanks.

[Devryd]

you could try lapping your cpus 
i recently read that the 9900k has problems with really not flat heat spreaders

[Bananasplit_00]

TT make pretty crap watercooling stuff, your fans might be really bad at static pressure, maybe there is a kink in the loop? 

[Master Disaster]

Swap the CPUs and see if the temps also swap.

[Mattias Edeslatt]

As @Master Disaster says, swapping the CPU:s would be the first thing to do in a situation like this to pinpoint the problem as you have two identical CPU:s.

[Benjeh]

13 hours ago, CSR1978 said:

I have two almost identical computers running with the same motherboard (Gigabyte z390 Master), same CPU (i9-9900k), same RAM (Corsair Vergence 32gb), same SSD (Samsung 970+ 1TB), same power supply (Corsair 800w) and same OS (Windows 10 pro).

 

The only difference between the two is that one resides in a standard, metal Corsair atx case and uses a beQuiet air cooler, and the other is in a Thermaltake open case design with a custom water cooler.

 

The water cooler uses all Thermaltake components (copper CPU block, copper 64mm thick x 480mm tall radiator with 8 fans in push pull design, and pump). It only cools the CPU.

The problem is that the air cooled system runs at full load significantly cooler than the water cooled system. Both are overclocked with the exact same settings (all cores to 4.7ghz). Both are stable. However, the air cooled temperatures peak at high 80 deg C and the water cooled peaks at 110 deg C running any type of benchmark (geekbench and timespy specifically).

 

Why is the air cooled system outperforming the water cooled system? Ultimately, this results in me being able to overclock the air cooled system to 5.1ghz, stable.

 

I've already tried reseating and repasting the water block. I very diligently flushed the radiator before installation as well as ran a pre coolant cleaning solution for 12 hours. So hopefully there is no debris stuck in the water block. The pump is running, water is flowing. The pipes warm up, so I know it's drawing heat from the CPU. The radiator fans are all blowing with nothing obstructing the air flow.

 

Did I just get unlucky with the CPU lottery? Does the CPU assembly line have a bigger effect than cooling system choice? Is the $800+ of water cooling parts a waste or a joke?

Please help with any input or suggestions. Thanks.

Are teh setting in bios exactly the same? Are they the same mobo? are the fans on his at 100% while yours aren't? Are you using static pressure fans? What about your mount on the waterblock? is it actually making full contact with the block? Has he delidded? Have you? too many variables!

[_Hustler_One_]

As far as I go and researched in PC community, I see more and more and more that liquid cooling isn't worth the money, mind, time, emotion, and all the hassle of their potential failure points.

 

Air cooling FTW! Install it and forget it, and having a great day with a great PC cooling from a great value.

[_Hustler_One_]

On 4/13/2019 at 9:10 PM, CSR1978 said:

The only difference between the two is that

 

one resides in a standard, metal Corsair atx case and uses a beQuiet air cooler,

 

and

 

the other is in a Thermaltake open case design with a custom water cooler.

Sweet..

[bowrilla]

Have you thoroughly bled the loop? Air bubbles can make temperatures sky rocket. Swapping cpus is one option to make sure that it's not the CPU itself. 

[Tristerin]

Recently did my first custom loop.  Recently swapped out AIO's and air coolers on my rigs.  What I noticed was user issue causing temp issues that didn't make sense.  I.E. a bad CPU block mount.  Bad TIM spread.

[Blai5e]

1 hour ago, Tristerin said:

Recently did my first custom loop.  Recently swapped out AIO's and air coolers on my rigs.  What I noticed was user issue causing temp issues that didn't make sense.  I.E. a bad CPU block mount.  Bad TIM spread.

Or as somebody else on here did (in a rush) recently, forgot to remove the protective sticker off the bottom of the waterblock!

 

 

Quote

I have two almost identical computers running with the same motherboard (Gigabyte z390 Master), same CPU (i9-9900k), same RAM (Corsair Vergence 32gb), same SSD (Samsung 970+ 1TB), same power supply (Corsair 800w) and same OS (Windows 10 pro).

 

<snip>

 

Both are overclocked with the exact same settings (all cores to 4.7ghz). Both are stable. However, the air cooled temperatures peak at high 80 deg C and the water cooled peaks at 110 deg C running any type of benchmark (geekbench and timespy specifically).

You ain't overclocking if your all-core turbo is 4.7GHz, that's the default behaviour of the i9-9900k. Further, I don't know if you are really getting 110°C, the Tjunction (max temperature of the die) for the i9-9900k chip is 100°C.

 

To your problem... questions to ask:

• Have you tried setting the AVX offset? If it is set to "auto", try setting it to 2 or 3.
• What speed are you running your pump at? I find the sweet spot on my D5 PWM to be around 40% (~2000rpm).
• Have you tried reseating your CPU & block (and backplate)? You never know!
• Have you disassembled your block to see if there is any blockages or if it was assembled correctly?
• Did you flush your radiator before installing it? Bits of solder and paint flecks can be present in brand new radiator just waiting to block cold plate micro fins.
• What temperature is the liquid in your loop? This is the temperature reference I use to build my radiator fan curves upon. You may need to purchase an in-line 10kΩ sensor such as Phobya G1/4 Temperature Sensor

.

BTW.

I run a 9900k & 2 x 1080TI's on a full EKWB open loop using 420mm & 240mm PE radiators and haven't broken 85°C on the CPU no matter what load (be it a heat virus-type stress test, TimeSpy or whatever) I throw at it even at 5.2GHz all-cores @1.42V..

[SolarNova]

Are the CPU's running the same voltage ?

 

Sounds to me you have an automatic boost feature enabled, which isnt really OC'ing ..well not properly at least.

 

If you have checked all the bios settings and they are all the same, and crucially all set to specific settings, especially make sure voltage is not on Auto, then the next thing to do is swap the CPU's, if its not the MB bios doing it then its likely a difference within the CPU.

 

480mm RAD custom loop should not be getting beaten by an air cooler if all other variables are accounted for between the 2 systems.