Very curious about your results with the 645 lt. My gpu temps are okay for the most part with my x52 at the bottom, but if the 645lt still lets me watercool my cpu and keep my window panel I might just switch to that.
Indeed you are right. While using 645LT, this is easing by far use of windowed side panel...as main exhaust is now top fan.
Right now, my testings are finished with 645LT. It provides slightly better temperature & lower noise than my Noctua C14S setup (dual fan as exhaust) on my R7 3800X (OC 4.3Ghz @1.3125v), and no negative impact on GPU thermals. I've also managed to run Asetek pump at 5v only (1350 rpm, monitored as 2700), making it pretty quiet...and with no impact on performance as loop is small on 645LT.
For info I'm using 645LT with only Noctua NF-A09x25 PWM (2000rpm max), but it worked almost as good with NF-A09x14 (2500rpm), but it was a bit noisier. I even tried push/pull (NF-A09x14 and NF-A9x25...giving a boost of 1-2°C on cooling..

)
https://smallformfactor.net/forum/t...erberus-x-complete-build-log.2007/post-179453
Previously while using 240mm bottom radiator (intake), GPU thermals were clearly impacted (from 75°C to 84°C on temperature and GPU fans speed from 1800-1900 to 2500 max). My GPU is overclocked GTX1080ti that can draw 330W max (average 300W on demanding title, like Gears 5).
Now I'm looking to build best setup with 92mm watercooling. I'll share them, if successful indeed..
