[SOLVED] Is my cooling/ mobo enough for i9 9900K

[name68]

Hello, do you think I could run properly (with no oc) i9 9900K on my MSI MPG Z390M GAMING EDGE AC ? Cooler is Corsair H80i v2 (it should cool as good as NH-D15 according to the reviews - it has push/pull and very thick rad). My case is Corsair Carbide Air 240. I do have opportunity to upgrade from my i5 9600K to i9 9900K just for 85 dolars more than is my i5. Thank you.

 

[alceryes]

I have the MSI Z370 Gaming Plus with an H80i v2 cooling an i9-9900k.
Mine is working fine. I'm overclocking slightly and generally run between 1.23 and 1.25v to the CPU. Unfortunately, My CPU can't maintain speeds when running Prime95 w/AVX2 small FFT stress tests. The H80i is good, but not that good. It runs fine outside of those specific tests, without downclocking.

 

[Karadjgne]

The H80i is roughly a 200w ability cooler. The 9900k can hit 200w on stock values, all core, on something like Prime95. If you want to use p95 for checking against possible extreme gaming temps, disable the AVX. Games use none-minimal AVX and there isn't a game I've ever heard of using AVX2 or AVX-512. Those are professional content creation type instructions limited to a few different programs and rarely ever seen in public normal usage.

So with a 200w cooler on a 200w cpu, expect behavior similar to an older i7 on a stock cooler, namely high 90's when maxed. Gaming will usually only hit @ 70% loads at best, so temps will run @ 55-65 on average.

 

[mdd1963]

I'm unconvinced that such a small radiator and a single fan will keep up with a D15 in sustained thermal loads...

Smallish radiators often have their fluid warm up a tad too quickly, ...which leads to less cooling....which leads to warmer fluid....etc...

Especially with a 9900K....I'd be leery. (And I'd be happy to be wrong, if it handles your thermal scenario, great...)

 

[Karadjgne]

The H80i uses a double thick radiator and 2x fans in push/pull.

As far as keeping up with a D15, there's plenty of coolers that'll beat it, some easily, if the loads are within the range of the cooler. It's only the D15's 250w+ capacity that tops almost all others, along with the Cryorig R1 etc, but even sustained loads aren't an issue. It's all dependent on the actual load.

Rads differ from heatsinks in one vital area. Where a heatsink fights directly with cpu temp vrs case ambient for its cooling efficiency delta, a rad fights with its coolant vrs ambient. The coolant itself will rarely get beyond 40°C on a 23°C outside ambient, or 45°C on a 30°C case ambient. Cpu temp doesn't affect the coolant in the slightest, the wattage output does. There's a huge difference in an i3 at 70° and a i9 at 70°, just in sheer wattage. Idle temps on an aio are next to meaningless, load temps just a value placed on capacity, not so much like an air cooler where load temps are a value placed on efficiency.

While many equate aios and aircoolers as being the same thing, but just have a difference of where they dump their heat, they'd be wrong. Aios are almost identical to full custom loops in how they work, they are both liquid coolant mediums, the only thing an aio and an aircooler have in common is lack of modularity. One piece units you stick to the cpu.

 

[rigg42]

The Motherboard should handle it although I recommend getting some airflow on the VRM heatsinks. A 120mm up top should suffice. The cooler will be inadequate for anything more than gaming loads IMO. I would change it.

 

[Karadjgne]

Agreed. Recommended minimum size aio for the 9900k is a good 240mm, with preference for a 280mm/360mm. For air cooling, nothing short of full size monsters like the Noctua NH-D15.

The 9900k is a step cpu. Unlike most others that'll run all cores/threads regardless of voltage/temps, the 9900k will only allow progressive cores/threads to open up and be used if there is sufficient power and temp space. If you hit 80's with just 6/12 due to lack of cooling and moderately high voltages, it literally won't let you push the full 8/16.

You can't over-cool a cpu, but it's very easy to under-cool one, especially that particular cpu. It's literally a case of go big or go home, there's no halfway measures.

 

[geofelt]

$85 for an upgrade to a 9900K seems like a good deal.

Since you already have the H80 cooler, you have the means to accurately decide for yourself.
The Intel performance maximizer will account for your cooling and do the best overclock that is possible.

Much will depend on your case and how the H80 radiator is mounted.
If you mount it to take in fresh air, your cpu will be cooled best.
But the hot air will not be so good for your motherboard and graphics card cooling.
I might think mounting the H80 in the rear as exhaust might be the best way overall.

In a good case with good ventilation, I might expect the NH-D15(or NH-D15s) to do a better job overall.

No need to decide now, try your H80 and see how you do.
My guess is that you will find it adequate.

 

[Karadjgne]

Yep. The D15/s is definitely a better cooler. It's more efficient than the H80i, and there's a 50w difference in capacity, so as wattage output from the cpu climbs, it's a slightly smaller percentage of the total on the curve, further adding to lower temps. You'll get roughly the same temps with the 9900k at 250w on the D15 as you would with the H80i at 200w. So with both at similar wattage, it'll make a difference.