Well do you have a flowmeter attached to it? there is no flowmeter integrated in the CPU block. The Vision unit has a socket behind the screen to connect a flowmeter but i'm not sure it's very accesible anyway.

The temp sensor in the CPU block is measuring coolant temp, not the CPU temp.

You can connect a flow meter to the flow header inside the block but it is not an ideal solution. Getting the block apart to access the header is tricky and getting the Vision display back into the block with the flow sensor cable and the USB cable both exiting the block is difficult to do. My suggestion is to buy a High Flow Next (#53293) and connect it via USB. They are considered to be the most accurate flow sensors marketed for custom loops but can be hard to find in stock. The High Flow 2 (#53292) and High Flow LT (#53291) both have the same flow sensor as the High Flow Next but no USB interface, LEDs, or display. The High Flow 2 has a coolant temp sensor, the High Flow LT does not. These sensors can connect to the flow header on the CPU block (if you can get it apart to plug in the sensor cable and then get it back together).I think the required cable is included.

For the USB connections, you can get a Hubby7 (#53230) which is a very well designed 7-port USB2,0 internal hub that can be Sata or USB powered. The Hubby7 can also be hard to find in the US. A good alternative is the NZXT AC-IUSBH-M3 (LINK) which is much easier to find. All of the Aquacomputer USB devices have a single row 5-pin connector. A standard 9-pin USB header can have 2 of these 5-pin connectors connected. There is no keying so be sure you do not plug the USB 5-pin cable in backwards. Note that a standard 9-pin USB header has 5 pins in 1 row and 4 in the other. The extra pin is just a ground pin.

If you want to add more temp sensors, Aquacomputer sells a bunch of different versions. They all have a 10K NTC temp sensor but the connector on the other end varies. The CaliTemp models are different. They are more accurate but only connect to an Aquaero controller via Aquabus. You need to decide which device you are going to plug the temp sensor into then make sure you order one that has the proper connector. The temp header on a Vision and the High Flow Next are different than the temp header on an Octo, Quadro, and Farbwerk360. For plugging into a Vision or HIgh Flow Next, they have #53218, #53219, #53220, #53211, and #53227. For Octo, Quadro, and Farbwerk360, they have #53066, #53067, #53147, #53025, and #53206. Some of these are fittings with a temp sensor built in, some are just the temp sensor. You can look them up on the Aquacomputer online store. I may have missed some models.

You're welcome, and good luck with your system.

Have you does the VARIO adjustments? If yes, I am curious about how much the CPU temps improved. I considered getting a CPU block with VARIO but decided against it and just got a block with the Vision display. My research on VARIO indicated that you might get 2° to 4°C from VARIO. It really depends on how flat the IHS is in the first place, so its a crap shoot whether the temps will improve or not.