Can LL120 fans be installed onto a H100i v2 radiator?

[charlesandyzhu]

So I have a Corsair 460x case with 6 LL120 fans that I bought separately and plan to install into the case. I’m also planning to buy the H100i v2 for my Intel core 8700K (which I’m going to overclock) but I’m unsure of where to the radiator it the case. I was thinking about putting it in the front of the case as it may be too thick to put on the top, so I was wondering if it would be possible to install two LL120 fans into the H100i v2 radiator (for more colorful fans) and then place the radiator in the front of my case. My overall airflow plan is to have intake at the front and exhaust the air through the back and top.

My specs:
Motherboard: Z370-E
CPU: Intel Core 8700K
RAM: 32GB (2x16) DDR4 RAM
GPU: ASUS ROG STRIX 1070 Ti

 

[Aeacus]

While you can install LL120 fans on your rad just fine, do note that LL120 performance is a lot weaker than the SP120L fans which come with the rad. For a rad fan, you want a fan to have high static pressure so it has the power to push air through the rad. Here are the specs of both fans:

SP120L
Airflow: 74.42 CFM
Static pressure: 4.00 mmH2O
Mar RPM: 2700
Noise: 37.68 dB(A)

LL120
Airflow: 43.25 CFM
Static pressure: 1.61 mmH2O
Mar RPM: 1500
Noise: 24.8 dB(A)

As far as where you put your rad (front intake or top exhaust), it doesn't matter much temps wise. Diff is only about 2-3 degrees Celsius.

 

[charlesandyzhu]

While you can install LL120 fans on your rad just fine, do note that LL120 performance is a lot weaker than the SP120L fans which come with the rad. For a rad fan, you want a fan to have high static pressure so it has the power to push air through the rad. Here are the specs of both fans:

SP120L
Airflow: 74.42 CFM
Static pressure: 4.00 mmH2O
Mar RPM: 2700
Noise: 37.68 dB(A)

LL120
Airflow: 43.25 CFM
Static pressure: 1.61 mmH2O
Mar RPM: 1500
Noise: 24.8 dB(A)

As far as where you put your rad (front intake or top exhaust), it doesn't matter much temps wise. Diff is only about 2-3 degrees Celsius.

Also, would there be an issue if I decided to do a push/pull setup at the front of my case where the LL120 fans are at the front (for looks) and the SP120L are at the back (for static pressure and airflow)?

 

[Aeacus]

I advise against using different specs fans on a rad in push-pull. Reason behind it is because SL120L most likely will suck the air through the LL120, making LL120 to spin faster than it's rated for. You may get away with it for some time until the bearing inside LL120 gives away and fan bearing is either seized in place (blades doesn't turn at all) or breaks, making the fan speed uncontrollable.

Btw, AIO isn't the only cooling option for your CPU. Air cooling with big heatsink is also one great way to cool a CPU, e.g Be Quiet! Dark Rock Pro 3,
review: https://www.tomshardware.com/reviews/be-quiet-dark-rock-pro-3-cpu-cooler,4350.html
pcpp: https://pcpartpicker.com/product/9bFPxr/be-quiet-cpu-cooler-bk019

 

[Karadjgne]

Push/pull should always be done with same fans using same signal source, or you get a nice and loud hum as the fan blades will 'slap' incoming air. Kinda like the noise you get if you blow into a oscillating room/desk fan. Mix-n-match is a bad idea.

While what Aeacus says about the 2 fans is perfectly correct, it also only applies to maximum outputs. If you aren't using full speed on the SP120L fans, but only spinning them at @1500rpm instead, you'll get equitable performance from either at that same rpm.
But, also there's limits. The SP120L is capable of higher performance (and therefore better temps when the cpu is pushed hard) than the slower LL120 which will cap out at its 1500rpm first.

So yes, you can use the other fans if you want to, but it could affect your hard load temps as the fans won't move enough air with enough force to keep up with cpu demand.

And yes, while I personally prefer AIO's, there's a lot to be said (again as Aeacus said) for a good aircooler, although I do have a preference for the beQuiet Dark Rock Pro 4 or the Scythe Fuma Rev.b.

 

[Aeacus]

While Dark Rock Pro 4 is the successor or Dark Rock Pro 3, i prefer the older cooler since it cools better. Tom's Hardware also did a review of Dark Rock Pro 4 where they compared it against Dark Rock Pro 3 as well.

The Dark Rock Pro 4 doesn’t seem to muster the same cooling potential as its predecessor, the Dark Rock Pro 3, although both be quiet! models outperform the Cooler Master MasterAir MA610P and the FSP Windale 6 in thermal load comparisons. However, the Dark Rock Pro 3 and Dark Rock Pro 4 share very similar designs. Can we even begin to deduce where the differences lie?

Both of the be quiet! Dark Rock Pro coolers make use of dual fans, and while the Dark Rock Pro 4 primary fan at full speed spins approximately 100 RPM faster than the Pro 3 primary fan, the secondary fan for each cooler tells a tale of sharp contrast. The Dark Rock Pro 3 secondary tach reading reported 2080 RPM at 100%, while the Dark Rock Pro 4 secondary tachometer shows a reading just over 1500 RPM...more than 500 RPM difference.

review: https://www.tomshardware.com/reviews/be-quiet-dark-rock-pro-4-cpu-cooler,5559.html
pcpp: https://pcpartpicker.com/products/compare/9bFPxr,F3gzK8/

 

[charlesandyzhu]

So overall, if I were to replace the SP120L fans with LL120 fans on the H100i v2, would it be enough to cool an overclocked 8700K?

 

[Karadjgne]

Sure. But thats a matter of preference over performance. The cpu does not care if it's 70°C or 45°C, runs just the same. It's only users who freak out if the cpu is running at 70°C instead of 45°C.

So if the temps are acceptable to you, then alls good. If they aren't, and the default fans are more to your liking, then there's that too. But as far as capacity goes, the h100i v2 is plenty for an 8700k OC.

 

[charlesandyzhu]

Sure. But thats a matter of preference over performance. The cpu does not care if it's 70°C or 45°C, runs just the same. It's only users who freak out if the cpu is running at 70°C instead of 45°C.

So if the temps are acceptable to you, then alls good. If they aren't, and the default fans are more to your liking, then there's that too. But as far as capacity goes, the h100i v2 is plenty for an 8700k OC.

Okay, thanks! Do you have any recommendations for the maximum temperature an overclocked CPU should be before there is risk of damage?

 

[Aeacus]

At 90°C, you'll get CPU thermal throttle and at 100°C, you'll get CPU damage which in most part is counteracted with PC automatically shutting down to prevent further damage to CPU.

At gaming loads, AIO cooled non-OCd i7-8700K runs at about mid 60°C with spikes over 70°C. OC'd to 4.9 Ghz, i7-8700K runs at about mid 80°C with spikes over 90°C.
Further reading: https://www.tomshardware.com/reviews/intel-coffee-lake-i7-8700k-cpu,5252-12.html

 

[Karadjgne]

Temp usually isn't an issue with damage, as Aeacus pointed out the cpu will regulate itself by throttling and shutdowns. The biggest contributer to damage is the voltages and current used by the cpu at OC levels.

Oc is absolutely not necessary for this level of cpu. It's purely a hobby, a want, bragging rights, personal satisfaction. So actual attained speeds are up to you as far as the cpu will let you go. I'd be happier with a full core 4.8GHz at 1.3v than a full core 5.0GHz at 1.4v, the extra 200MHz isn't worth pushing the voltages that high, to me.

Since cpu temps are governed by both speed and power used, they vary from pc to pc, but generally if the cpu can be kept at below @70°C under long term duress, then the occasional spike is fine.

 

[charlesandyzhu]

Temp usually isn't an issue with damage, as Aeacus pointed out the cpu will regulate itself by throttling and shutdowns. The biggest contributer to damage is the voltages and current used by the cpu at OC levels.

Oc is absolutely not necessary for this level of cpu. It's purely a hobby, a want, bragging rights, personal satisfaction. So actual attained speeds are up to you as far as the cpu will let you go. I'd be happier with a full core 4.8GHz at 1.3v than a full core 5.0GHz at 1.4v, the extra 200MHz isn't worth pushing the voltages that high, to me.

Since cpu temps are governed by both speed and power used, they vary from pc to pc, but generally if the cpu can be kept at below @70°C under long term duress, then the occasional spike is fine.

Okay, thanks to both you and Aeacus!