A gt copy without gt quality
Updated 4/4/13 see bottom for updatei received 4 of these fans. Visually, they look pretty good. I really like the white impeller. The gap between the blades and the chassis is very large on these fans. For fans that are supposed to provide high static pressure this is a bad sign, now i know why all the pictures are taken at an angle. The cable sleeving is as well low quality and the cables show right through.Testing:i hooked each fan up to a power supply and gave them a free air spin to get an idea of their noise. The first fan squealed like a pig. I pushed the impeller down into the chassis and got that telltale 'pop' when it seated. That fixed the problem. 2nd and 4th fans required same treatment, so make sure the impeller is fully seated before installation! Free air sound is good, they had no pronounced whine or drone to them. Next i swapped them for the gts on my test bench. Wow, what happened? They were a lot louder now. I double checked to make sure all was tight and proper and it was, they were just very loud now. I pulled one off and ran it free air, quiet as a mouse, hooked it right back up and ran only that fan, noisy! From past experience i figured i knew what was going on. I pulled out a rad question and fitted it between the fans and rad. This helped tremendously. About an 85% reduction in noise i would guess. So the problem here is that the motor/bearing is not very smooth and transferred vibrations into my radiator/test bench making the fans sound loud. Very disappointing. It may as well be that the extra space of the question reduced turbulence a bit. I did a paper test on them and there was about 1" less travel on the paper on the helix fans compared to the gts. Just for fun i threw on two other types of fan to see the difference in sound. First i tried noctua nf-p12s. They are absolutely dead silent even attached directly to the rad, but they don't push as much air as the helix or gts. Next i tried corsair sp 120 high performance with the 7v adapter to make them near the same rpm. They are somewhere in between the noctuas and the gts as far as sound goes and push a similar amount of air.Conclusion:the helix seems to perform just under the gts for air flow and static pressure, but with a lot of motor noise coming through the frame so they sound much louder. Isolating the fans with a thin neoprene question eliminated most of this extra noise though. If you are doing a white build there really aren't many fans out there to choose from, and most of them are free air models and not for rads. You could go with nxpc whites but would definitely have to do p/p to get the same airflow as these. Just pick up some question and i think you'll be happy with these as long as you don't expect the quality of gts or noctuas. Then again, you aren't paying the price for gts or noctuas either, and question are cheap.-1.5 stars for motor/bearing noise.-.5 stars for the huge gap between the blades and the chassis (less static pressure) and for the cable sleeving. It would have been better to use a black cable like corsair did instead of using cheap sleeving.Updatei am getting ready to build a new machine and i have so many fans to choose from that i decided to do a real test. I wasn't happy with the traditional "paper test" since it measures airflow more than pressure. So i made a pressure chamber and used mm of water in a thin piece of tubing to compare fans. Here are the results in order of static pressure, lowest first:swiftech helix w 7v adapternoctua nf-p12 w 7v adaptercooler master blademaster with 7v adapterswiftech helix - full speedgt ap15 w 7v adapternoctua nf-p12 - full speedcorsair sp120 hp w 7v adaptergt ap15 - full speedcooler master blademaster - full speedcorsair sp120 hp - full speedthe corsair sp120 hp is an absolute beast. It was better with a 7v adapter on it than a nf-p12 was at full speed and it produced almost twice the pressure in my test as the ap15, albeit at a marked increase in noise. The ap15s are right in that sweet spot as they aren't loud, have good static pressure and move a decent amount of air. The sp120 whoops the ap15 at full speed but you pay for the performance with noise. The swiftech helix was surprisingly low performance when it came to pressure. As far as airflow they are fairly close to the ap15s but they are terribly lacking in pressure. I attribute that the the huge gap between the blades and the frame, too much air can slip through. If air slips through then so do your hopes of building pressure.