Originally Posted by Jpmboy
^^ lol, reliable sources.
I've put 2 EK vector blocks on my 2080Tis and a bitpower block on a third. All three hold the cards between 10 and 15C above loop (cold side) temperature at full load pulling 300W (or more each). Any real comparison is not a trivial exercise.
I'll likely go with EK for my VII, but bitspower is quite good too. (Have two Bits blocks on two Titan Vs - simple design and very effective)
It's pretty reliable when a number of the people have bought both, and some are very experienced with water cooling. It's been replicated across various forums, and neither block has contact issues, and there are far more EK fans than Bykski fans.
Every single group test of bitspower GPU blocks has put them either at the absolute bottom of the pack, or very near it. They're nicely made, and I have a bunch of their fittings (best on the market), but they've yet to prove their designs are anything other than scraping the bottom of the barrel in terms of performance, re: GPU blocks. That said, they're probably prettier than anything else besides AquaComputer and WaterCool Heatkiller GPU blocks, so if that's most important for you, go ahead.
The reason I hold out a little more hope for Phanteks is that they're very new to the water cooling game, and whilst their first few GPU blocks have been only a little better than bitspower's offerings, I suspect there's more likelihood of improvement.