Quiet CPU coolers for Lian Li PC-Q21

dedocuk · 3 May 2018 at 23:39

Looking at building an 8700k system into this (no graphics card, use is processing not gaming) and I'm trying to figure out what CPU coolers can be fitted in, low noise is high priority since PC sits on desktop.

I know the data sheet says 60mm clearance but it's not clear if this is height from motherboard or top of CPU -- does anyone have an exact measurement for this?

Maybe a Big Shuriken 2 will fit (57mm), or maybe not -- either way clearance to PSU will be very small. Has anyone tried this? [PSU will be Corsair SF450 assuming I can find one, out of stock everywhere]

Maybe a Cryorig C7 (47mm) will keep it cool, but could be too noisy. Cu version is expensive and hardly any cooler according to reports.

Noctua LH9i is quiet and fits but probably won't keep up with an 8700k, even without overclocking. Would an 25mm A9-PWM improve the cooling over the fitted 14mm A9x14, flow is >50% higher?

Looks like an AIO will fit at the bottom of the case, Alphacool Eisbaer LT120 could be an excellent (but expensive) solution -- except their manual says the radiator must be above the pump to avoid noise in case of air bubbles. [anyone know if this is really a problem or them playing safe?]

Any other suggestions?

InfiniteNoise · 4 May 2018 at 13:18

About AIO pump being above the radiator, it's probably them playing safe, if things were done properly at the factory, there shouldn't be any issues. I've seen photos of AIO coolers set up that way and I haven't seen anyone complain about it.

LuckyBenski · 11 May 2018 at 13:20

Generally it's the height from top of CPU as this is where the cooler starts - it allows you to measure cooler height itself. It also negates variation from standoff height etc. So usually case specs list cooler height and coolers list their actual height so the figures match.

Regarding pumps, air will be inclined to move upwards. If there is a section of tubing above the pump that will probably collect air. It might be noisy, YMMV

LuckyBenski · 11 May 2018 at 13:21

Also, are you planning on overclocking as you bought a K series CPU? Overclocking and quiet, small coolers is a likely contraindication

voidshatter · 11 May 2018 at 22:00

8700K in Q21? That's challenging! I ended up with L9i cooling 6600T/7700T. Got 200Gflops with 7700T and I bet it's hard to beat it with limited TDP and cooling.

By the way, you can't just undervolt the K to mimic the T - they have different voltage curves and the K is bad at undervolting. For that reason I sold both my 6700K and 7700K after attemps of undervolting to beat the T variants.

Good luck finding a cooler better than L9i - it might exist but meh...

dedocuk · 12 May 2018 at 15:02

LuckyBenski said:
Generally it's the height from top of CPU as this is where the cooler starts - it allows you to measure cooler height itself. It also negates variation from standoff height etc. So usually case specs list cooler height and coolers list their actual height so the figures match.

Regarding pumps, air will be inclined to move upwards. If there is a section of tubing above the pump that will probably collect air. It might be noisy, YMMV

Pump will probably be the highest thing in the loop, dpending on which way the pipes go.

dedocuk · 12 May 2018 at 15:03

LuckyBenski said:
Also, are you planning on overclocking as you bought a K series CPU? Overclocking and quiet, small coolers is a likely contraindication

Leaning towards tha Alphacool which should have no problem even overclocked -- though if I do this it'll only be mild overclocking, not "how fast will it go if I jack the core voltage right up and don't care about heat"

dedocuk · 12 May 2018 at 15:06

voidshatter said:
8700K in Q21? That's challenging! I ended up with L9i cooling 6600T/7700T. Got 200Gflops with 7700T and I bet it's hard to beat it with limited TDP and cooling.

By the way, you can't just undervolt the K to mimic the T - they have different voltage curves and the K is bad at undervolting. For that reason I sold both my 6700K and 7700K after attemps of undervolting to beat the T variants.

Good luck finding a cooler better than L9i - it might exist but meh...

With no graphics card, Alphacool 120 at the bottom, maybe with the fan replaced with a Noctua NF-A12x25, I don't think I'll have a cooling problem even in the Q-21.

voidshatter · 12 May 2018 at 17:01

dedocuk said:
With no graphics card, Alphacool 120 at the bottom, maybe with the fan replaced with a Noctua NF-A12x25, I don't think I'll have a cooling problem even in the Q-21.

If you have enough clearance for the pipes connecting the water pump (i.e. the power supply unit does not block the pipes or bend the pipes too hard), feel free to give it a try and I'm looking forward to see your LinX Gflops numbers