Originally Posted by CorsairGeorge
There are a lot of combinations of factors, but the H80 outperforms the H70 for a few reasons.
1) Much better coldplate/manifold design. The microfin array in the copper coldplate on the H60/H80/H100 is more efficient than the H50/H70 coldplate design. Also, they all feature a split-flow manifold that puts the coolest water directly in the center of the coldplate to add a bit more cooling capabilities.
2) Better fan design - the higher static pressure of the new fans means that even at relatively low RPM, they can push decent air through the radiator and not worry about the high restriction.
3) Radiator optimization for lower speed fans. The H70 performed well with high speed fans, but was too restrictive for low speed fans. The H80 radiator is designed to hit the sweet spot with fans between 1000RPM and 3000RPM, fairly low speed. If you were to put an H70 radiator on an H80 pump head, the H80 would outperform it at lower RPMs (1000-2000) and the H70 would start taking the lead at higher RPMs (2500+). The reason we went with the H80 radiator is because we felt that the majority of customers would be under the 2500 RPM level, and we wanted better performance at lower noise.
The past two years have taught us a lot in the all-in-one watercooling market, and the H100 is VERY competitive with the RASA 750 kit, so much so that when we test them in the oven, our results are within the margin of error of our tests.
All in all, we're looking at ways to make these products better every year, and trying new and interesting stuff every year. This is why I read these forums.
Last year we announced the 600T - you guys said you wished it had dual 120mm intake fans and the ability to turn the LEDs on and off. So when we developed the 400R and 500R, those requests were both incorporated.
Last year we announced the H70 - some people claimed it was loud, other people claimed the fans weren't good enough, and some people thought the mounting hardware could be improved. So this year, we've added fan control so you can select how loud you want it to be, we've got much better fans, and the mounting hardware is a lot easier to use.
I've read every page of this thread since day 1, and I'll read every page of the H100 thread, the 400R & 500R thread, and any other threads about my products when they show up. I'm the PM for cases, cooling, corsair link, and power supplies, and this is how I build my products.
Listen to what you guys want -> Build what you guys want -> Repeat as necessary
Sure, full-built watercooling guys are going to hate on our products, but we're not competing with them yet.