Corsair 1000D case, 2x480 and 2x360 rads in push/pull. All watercooled, even the RAM. Due to the volume, one D5 does not provide enough head pressure. One D5 pump provides about 0.5 GPM flow rate, 2xD5 in series 0.8 GPM, and then with 3xD5 I finally get >1GPM flow rate. It's an overkill even for an AI enterprise, but hey, I am a PC enthusiast.
By concept the more fans, capcity and exposure you have, the less delta you get. Which is true, but if the environment (aka my room) with closed doors absorbs all that heat, especially during peak summer day... No matter how many rads or fans you have, if your room is getting hotter. So both the PC and the environment temperatures need to be kept consistently 'cool'. I will invest in an aircon this summer probably, but I need to spend funds on exterior as well unfortunately, and I just bought a 5090 so... I will see.