There's nothing strange about this. In the BIOS your CPU is generally running at full base clock speed (Some BIOS have options to configure the CPU to run at full boost speed prior to the Windows environment but most do not and even fewer actually change that setting) while in Windows you are likely seeing the result of many background tasks running whether you've actually opened anything to run or not.
Also, I'm not sure Command center is the right application for monitoring on this. It should be using the Corsair iCue software if I'm not mistaken and that should be where monitoring is done aside from in the BIOS. Personally, not to be contrary, but I dislike Command center, Armory crate and other motherboard "utilities" as they generally seem to create more problems than they solve and IMO should ONLY be used when it is 100% required for RGB controls, which honestly is mostly never since there are very good third party RGB control programs available through the open source community.
You really are overthinking this and worrying about something that is irrelevant. Simply create your curve based on the RPM settings that
Keep you sane
Ensure your CPU does not exceed 85°C core temps on any given core or package when under a 100% all core full boost steady-state load.
Idle temps don't generally matter at all so long as they are not particularly high and so long as you do not exceed maximum thermal envelope under full load. However, I'd agree that 65°C is probably excessive and I'd be very surprised if this was not due to the fact that you do not have the pump RPM set to full speed 100% of the time as it should be but instead configured for a lower or variable speed. It should not be. Set it to full speed and then make whatever adjustments are preferred to set your fans to the speed curve you desire.
I generally like to see CPU air and AIO radiator fans sit at about 30% at core temps below 60°C and then slowly ramp up at whatever intervals you prefer until they are at full speed at about 80°C.
You can find guidance on how to employ a steady-state full load below. Meant for testing overclocking configurations but the process is the same. There is no difference in the method of thermal compliance testing. Keep in mind this is a cut and paste from my overclocking guide some of it may not apply to your situation specifically.
Testing thermal compliance
Once you get to the Windows desktop, the first thing you will want to do is open HWinfo (Sensors only option), Core Temp or Ryzen Master and take a look at what your core and package temperatures are doing. At idle your core temps should be somewhere below 40°C in the majority of cases. Preferably somewhere in the mid to low 30’s. On some newer very high core count models, or if you are using the stock cooler (In which case you shouldn't be overclocking anyhow), then it might not be below the 40°C threshold.
If you are not overclocking and are ONLY testing the thermal compliance of the stock configuration, then don't be TOO concerned by a high idle temperature UNLESS you also have a high load temperature that is outside of spec. This WILL be affected by whatever the ambient temperature is in the room where you are, so if your are in a very warm region and have no air conditioning going you may have an idle temp that is a bit closer to 40. For cooler ambient rooms or regions it will likely show low 30’s-ish. Be aware that unless you have excessively high idle temps, say, above 40°C, then what your actual idle temps are is practically irrelevant. Cooler idle temps are not indicative of much of anything specific.
Very HIGH idle temps however DO indicate that there is likely a problem with an incorrectly installed CPU cooler heatsink, too high of CPU core voltage, AIO pump not at sufficient/full speed or some other cooling or voltage related issue. If you are using one of those other utilities I warned about in the beginning of this tutorial, it may also be that the utility is reporting falsely. In that case, go get HWinfo or CoreTemp and check again.
If idle temps seem fine, then leave your monitoring application open and run Prime95 (Either version 26.6 or the latest version with ALL AVX options disabled).
Choose the Small FFT option (NOT "Smallest FFT") and allow it to run for fifteen minutes. If you are using the latest version of Prime95 (Version 29.8 or newer) then you NEED to be sure to disable the AVX and AVX2 options in the main options window. When you disable AVX2 the option to disable AVX will become available. If at any point your core or package temperatures exceed 80°C for Intel or AMD Ryzen platforms, then click the “Test” menu at the top of the Prime95 window and select “stop” or “exit”. Do not simply click the "X" in the top right corner as that will NOT stop the stress test, it will only minimize it to the tray.
You MUST click Stop or Exit from the drop down TEST menu at the top left of the window to stop the stress test.
If you have an older AMD system that is pre-Ryzen, then measuring thermals is going to be a little different. If your AMD system IS a Ryzen based system, then testing will be the same as for Intel based systems.
On pre-Ryzen AMD systems they did not make, by any definition, measuring core temps accurate or reliable. On the low end of the scale their thermal sensor readings have long been laughable, sometimes showing temps that are well below what the ambient temperature is, which of course is not possible without some kind of Peltier cooler or active refrigeration. At the other end of the thermal range it’s not much better.
This is because AMD does not actually implement their sensor designs to be determined in the same way that Intel does. AMD uses a method known as distance to Tjmax. Tjmax being, in this case, the temperature at which AMD has determined bad stuff will start happening such as thermal throttling, shut downs and damage.
For this reason when you are testing thermal compliance, or just monitoring for general purposes, you need to be aware of this difference and purposely either use applications designed for use with AMD processors or make some settings changes in other utilities that will allow you to see distance to Tjmax rather than estimated core temps.
There are a couple of ways you can do this. First off, HWinfo generally has the appropriate fields which are labeled as Distance to Tjmax. I feel like the better choice though is either CoreTemp or AMD overdrive for monitoring Distance to Tjmax on AMD platforms. In CoreTemp you will need to go into the Options tab, click on Settings and on the Advanced tab check the box next to the setting for “Show distance to Tjmax in temperature fields” in order to change from the default and likely inaccurate core temperature display.
AMD overdrive shows Distance to Tjmax by default, and I don’t think there is any other way to monitor CPU thermals in that utility anyhow. Either of these is probably a good choice, but it’s also likely worth checking either CoreTemp or AMD overdrive against what you see for Distance to Tjmax in HWinfo and if the readings are pretty close to the same, just use HWinfo as there is a lot of other information available in the sensors display that is not available with these other two.
Regarding the actual Distance to Tjmax sensor readings, what you do NOT want to see is anything closer than 10°C Distance to Tjmax, ESPECIALLY if you are only in the first phase of your overclock configuration and have only made minor changes to the CPU multiplier and voltage at this point. If it drops below ten degrees to Tjmax you are getting very close to your thermal ceiling and need to revisit either your cooling solution or voltage settings.
If you can run the Prime95 version 26.6 or 29.8 (With AVX/AVX2 disabled) Small FFT (NOT "Smallest FFT". ONLY use the "Small FFT" for our purposes.) torture test for 15 minutes without exceeding 80°C for Intel/AMD Ryzen or dropping below 10°C thermal margin (AKA Distance to Tjmax) for AMD, then you are to some degree or other within specification for thermal tolerance.
It's important to note that when stopping or attempting to exit Prime95 that you MUST use the drop down file menu and choose either "Stop" or "Exit". Simply clicking the X in the top right corner like you would for most programs will not stop the test, and will leave it running in the system tray.
If you are very close to the edge however, this may be a warning sign that you don’t have much overclocking headroom since we’ve only barely set our multiplier to what is basically the all core equivalent of the default single core Turbo frequency (Speed). IF that is the case, you will want to either be very careful going forward or stop and think about upgrading your CPU cooler and perhaps looking at whether your case and case fan situation is really sufficient for what you are trying to do.