Kernel_task and bootpd

My Mac Pro 2009/10 with a few browser windows open and mail open and Quicken is running 1.4 percent kernel-task. My MacOS server, doing not much is running 0.4 percent, but I do not do Bootp on that Server, I let my Router do the DHCP stuff.

Do you have a Home/Office network set up? if so, is any device providing DHCP Service, or are you full manual? Do you have a firewall or other device performing Network Address Translation?

You may want to consider this little "discovery" Utility named Etreceheck. It can do a simple analysis and point out known Bad Actors and produce a pre-laundered report that can be pasted back to a reply on the forums.

Using EtreCheck to Troubleshoot Potential Mac Issues

Using EtreCheck to Troubleshoot Potential… - Apple Community

.

The very last section may need your attention:

Diagnostics Information (past 7-30 days):

2020-02-17 11:11:43 iStatMenusDaemon High CPU Use

Executable: /Library/Application Support/iStat Menus 6/iStatMenusDaemon

2020-02-17 11:09:07 bootpd High CPU Use

Executable: /usr/libexec/bootpd

2020-02-13 14:05:14 signpost_reporter High CPU Use

Executable: /usr/libexec/signpost_reporter

2020-02-13 09:17:21 CEPHtmlEngine.app Crash

Executable: /Applications/Adobe InDesign CC 2019/Adobe InDesign CC 2019.app/Contents/MacOS/CEP/CEPHtmlEngine/CEPHtmlEngine.app

2020-02-12 20:33:24 syspolicyd High CPU Use

Executable: /usr/libexec/syspolicyd

2020-02-11 13:40:00 Ulysses.app Hang

Executable: /Applications/Setapp/Ulysses.app

2020-02-11 13:39:53 mDNSResponder High CPU Use

Executable: /usr/sbin/mDNSResponder

I thing dropbox is way out of line. It looks to be trying to sync everything, all the time. Quit it and run it only when things are quiet.

Quit or force Quit Bootp -- if it does not show in the force quit box, select it by name in the list in Activity Monitor, then use the controls in the upper left corner under the red yellow green window controls. The leftmost (x) will force quit the selected task. Then see if it auto re-launches. If it does, something you have added (and there are a boat-load of them) is invoking it.

You should re-enable [√] Install System data files and security updates. The are mostly just tiny strings used for virus checking:

System Preferences > software Update > (Advanced) > [√] Install System data files and security updates

do you have TWO 16GB DIMMs installed? I expected they would be in slots 1 & 2, but as long as you think there are two and not Three or more, it is not an issue.

To test whether overheating is the issue, if you boot into Safe Mode and the kernel_task issue goes away, it is likely something you added.

if you are running a completely unnecessary so-called virus scanner, that can produce wasted resources like you describe.

Try an SMC reset to get everything working together again.

How to reset the SMC of your Mac - Apple Support

.

Bootpd is the name of the DHCP server that allow your Mac to pass out local IP addresses to other devices on your network.

are you running MacOS Server?

Dropbox is not a Mac-native App. when you set it to keep stuff in sync, it is unrelenting in reading all your files, again and again and again, looking for any that may have changed.

Time machine, by contrast, uses the Mac File System Event Store to check what folders have changed recently, so as long as Time Machine has been allowed to run in the last day or two, it can quickly determine what needs to be backed up.

Your DIMMs are fine, or it would have yelled at you. Older Macs required the DIMMs in slots 1 & 2. It appears this model Mac Pro does not care.