I like the NZXT H1, it’s a good case in a lot of ways.
It’s easy to build in, with everything pre-routed and ready to go. It comes with a liquid cooler in the form of an AIO CPU cooler, a 750 watt power supply, and a fan controller. It delivers all this at a price point that becomes reasonable when you account for all that is included.
Put in your motherboard, attach some cables, bolt on the CPU block, and voila — you have a computer.
The first version of the H1 was a fire hazard because of a faulty riser cable design.
The second version resolves the fire issue and adds more room for a beefy GPU along with other improvements such as a rear exhaust fan.
It’s not perfect.
After using M1-based macs for a couple of years I’ve become quite spoiled by effectively silent computing.
Straight from the factory the noise coming from this thing is constantly audible. It’s not so loud that it would be hard to talk over, or be distracting on calls, but it’s a constant noise where there doesn’t need to be one. This needs to get resolved. We are going to fix it.
The build
Case: NZXT H1 Version 2
CPU: Intel Core i5–13600K 14-Core (6P+8E)
GPU: Nvidia GeForce RTX 3070 Founders Edition
Motherboard: ASRock Z690 Phantom Gaming-ITX/TB4
Memory: G.SKILL Trident Z5 RGB Series 32GB (2 x 16GB) DDR5 6000
Storage: Crucial P5 NVMe M.2 SSD 1TB + Western Digital 2TB WD Green SN350
Power Supply: Corsair SF750–750 Watt 80 PLUS Platinum CertifiedProblem #1: the power supply fan noise
The power supply fan runs 100% of the time regardless of how much load the system it under. It’s also the loudest fan in the case.
Most modern power supplies have a 0 RPM fan mode— if your machine isn’t under load, the power supply fan isn’t spinning.
This problem is easy to solve by replacing the power supply, but that’s a costly option. After a couple of days of using the factory NZXT power supply, I replaced it with a Corsair SFX 750 which keeps the fan RPM at 0 unless it needs to be on. The power supply is now silent at idle, and provides only a quiet whir at full load.
One problem down, one to go.
Problem #2: the liquid cooler AIO pump noise
NZXT won’t allow you to control the AIO pump speed on the H1’s AIO. If they allowed that, the rest of this post wouldn’t need to exist.
From their documentation:
“With the addition of a fan controller to the H1 V2, you are now able to adjust the speeds of the included 92mm and 140mm fans. This controller also powers the H1 V2 AIO Liquid Cooler but is not able to control the pump, as the pump is designed to run at max speed at all times.”
That’s not great. AIO pumps are quite obnoxious when at high RPMs and the goal is silence. Also, the noise they generate is more of a high pitched whine than a whir, and it’s fairly obnoxious. By default this pump is running at over 4000rpm. For me it’s like listening to dentist’s drill.
It’s possible that their AIO, as claimed, is truly is designed to work only at max speed. But I don’t buy that.
It’s also true that perhaps by lowering the rpm I will lower the lifespan and/or heavily impact the performance. I also doubt this.
I think it’s more NZXT trying to ensure end users of their small form factor case don’t mess things up with settings, get high CPU temps and thermal throttling, and blame NZXT for it. I mean they already had the fire issue with the first one, don’t need more bad press here on version 2.
The plan:
If we can find a way to control the pump speed, we will be able to lower the noise level, with likely negligible impact to performance.
AIO performance is dictated by 2 variables:
1. Pump speed + Flow rate : How quickly the pump is circulating the liquid within the liquid cooling loop. This circulating water runs through the radiator where it’s cooled by the fan.
2. Fan speed + Airflow: How fast the fan is spinning and how much air is it sending through the radiator measured in CFM. This cools the radiator and the liquid within, thus cooling the CPU.
From experience, the fan speed is a far more important factor in controlling temps provided you have some movement of liquid. The H1 has a small AIO loop with only one component- the CPU.
Running that pump at 50% speed should highly reduce noise without losing much performance. The fan’s speed with then be dictated by a curve that biases towards low speeds under normal productivity loads while spinning things up at higher temps for rendering and gaming to control temperatures.
The solution
The H1 uses a proprietary 5-pin connector which plugs into their proprietary fan controller… so fixing this is not as simple as adjusting it from the bios or using a 3rd party fan software controller. The pump power and control goes straight into their hardware. There is no way to resolve this without a code change on their end or a physical modification.
The 5-pin cable is actually two cables, one 2-pin and one 3-pin. Below is a view of the situation. I decided to take the sleeve off the cable and separate the single cable into two. That made all this a lot easier.
The AIO Pump + Tach 5-pin connector goes to two place:
- The motherboard, which then tells the controller how fast the pump is going in rpm.
- The AIO’s pump which supplies and controls power to spin the motor.
I started by stripping the wires on an old PC fan and then using the bare ends to plug into the 5-pin proprietary connector to figure out what each did.
On one side of the connector 3 pins line up with the typical DC fan pin-out. On the other is the 2-pin cable they are using to connect to the motherboard to get the pump speed.
This of course presents a dilemma: How to proceed. Should I cut the cable and I assume for sure void the warranty? On a perfectly functioning thing?
Yes, yes we do this. For silence.
I took my 3-pin fan cable I had cut and exposed the wiring on, and did the same to the 3-pin side of the cable coming out of the AIO. This allowed me directly connect the AIO pump to the motherboard. (Notable: this is the way a normal AIO works.)
This solution is a new (and very professionally crafted) cable to the motherboard’s PUMP header. Immediately having done so I am now able to control the speed of the AIO pump through my bios and promptly set it to operate at 50% speed. I removed the 5-pin cable from the controller along with the 2-pin end. No longer needed.
This is where I’d explain the process of soldering and heat shrink wrapping the cable to make it a sturdy and long lasting connection — but I didn’t do that. I just did the twist the wires together and wrap it in electrical tape technique. Perhaps one day I will upgrade it.
authors note: he will never upgrade it unless it stops working, and even then he will probably just do the same thing again.
The reward
Performance
Cinebench 10-min multi core synthetic load showed no difference in CPU temps. Note: The 13600K is undervolted -110mV on CPU core and CPU cache.
I’ve upgraded the 140mm fan on the AIO to a Noctua NF-A14 PWM and switched it from exhausting air to intake. This gives me better CPU thermals at a slight expense to GPU thermals.
So now I have the H1 AIO plugged into my motherboard and my pump speed set to 50% which is reported at 2,800rpm by HWiNFO. I am using NZXT CAM to do fan curves on the CPU and rear fans, both of which sit at 35% until temps go above 65C. The BIOS controls the pump speed.
Stats
50% PUMP speed (mod): 82C max
100% PUMP speed (factory): 82C max
The GPU maxes out at 74C and seems quite content to sit there at full boost.
Silence
The machine is so quiet I have to turn off my HVAC to even hear it. Completely and utterly silent unless you push it — and even then it’s very quiet.
Cut some cables and you too can have a silent H1.
