Bests & Worsts Reviews from Amazon

There are dozens if not hundreds of all in one (AIO) add on liquid coolers on the market now. And Corsair has been making models for more than 10 years now at least. The previous H100i V2 units had more powerful pumps that were unfortunately prone to failure. So, Corsair worked with Asetek to redesign the pump for longer term durability. They also redesigned the RGB LED lighting and added their new "magnetic levitation" fans. And they upgraded the interface so the H100i requires no special BIOS setup (as the H100i V2 did for the CPU_FAN header) and is fully integrated into their new software iCUE. Now, that all sounds dandy, but how does it actually work? Well, when I finished installing my H100i Pro (the 240mm version with 2 120mm fans), my initial temps were only about 2 deg C better at rest compared to my previous CryOrig H7 air cooler, and about 7 deg C better under Prime95 load for my 8700k cpu (I used Grizzly Kryonaut as my thermal paste). A bit puzzled, I began looking into the iCUE settings and saw that I could set things to either Quiet, Balanced, Extreme or Zero RPM, but only for the fans. I saw in iCUE that the pump was running at about 1080 rpms but I could not click on it to set to a different speed or seem to adjust it. And when I put my head very close to the pump inside the case, I heard just the faintest whirling. Finally, after posting a question about pump speeds at the Corsair User Forums, I found that you need to go to the Performance tab on the left, then set it to another setting (it initially is set to "Quiet"), and then you can see the pump appear as an entry on your right that you can change. Then you can click on the fans or the pump and set them to Quiet, Balanced, Extreme or Zero RPM (which means the fans are not turning but the pump is still spinning - very quiet and almost passive water cooling). At this point, I think it is important to note that at no place in the included instructions is there ANY mention that the pump is initially set to "Quiet" mode, or how to change the pump speed, or how to setup the H100i Pro with iCue !!! (I am using iCUE 3.6.109) Without being mean to Corsair, this is extremely poor. And no doubt, many people will buy this unit, see not much improvement and then return it, never realizing that the pump is set too low to begin with. When I then put my pump into "Balanced" mode, it went from 1080 rpms up to 2150 rpms and the temperatures immediately started to drop. Now, temps are about 5 deg C cooler at desktop rest and about 15 deg C cooler under Prime95 loads. In "Extreme" mode, the pump ramps up to 2950 rpms and my resting desktop temps are about 7 deg C lower and my Prime95 temps are about 20 deg C lower for my Intel 8700k cpu. Big difference. (For day to day use, I keep my pump and fans set to "balanced" mode.) The fans also are high quality and I do not notice them until they spin faster than about 1800 rpms. (they go up to 2450 rpms) It is also great that there is a preset temperature lighting effect that you can set for the waterblock/pump head LED Corsair logo that changes from green to yellow to red based upon the temps you set for the internal coolant. So, once the kinks were worked out and I had everything set correctly, then the H100i Pro performed admirably. I have only been using my H100i Pro for one month so far, so I cannot say if Corsair changing the pump design is going to result in increased reliability. I can say that they should have stuck with larger 3/8 or 1/2 inch inner diameter coolant tubes (more water, can hold more heat), and they should have made those tubes enter the waterblock/pump head directly for less flow restriction. With the H100i Pro, the small little 1/4 inch tubes enter at cheap plastic 90 degree couplings that will hurt flow and increase temperatures (and increase pressure for the pump, leading to less life). Because of these small design flaws and the cluster$#@! lack of iCUE instruction on how to set the pump to higher RPMs in the instruction manual, I am deducting one star. Time will tell, and I will come back and update this review, but right now I would say that this is a good AIO cooler that needs a more detailed instruction manual and a few small design changes. 4 out of 5 stars for me.