FYI - Windows Update force-installed an Intel Software Component and an Intel Software Extension on the XPS 8930 in the last ~1-2 weeks, both for Killer internet. They made the Killer E2400 Ethernet on my XPS 8930 slow to a crawl again. They enabled all the Killer and xTend junk listed in services.msc and the Killer Control Center on Startup tab in Task Manager, which I had previously disabled.  So I disabled all of them, and then changed the Startup tab in Task Manager to disable KCC from loading at boot. Rebooted and back to full Ethernet speed again. I'm so fed up with this Windows Update nonsense that I disabled the option to let WU install "manufacturers' apps and icons". For Win 10, type Advanced system settings in Start>Search, open it, click Hardware tab > Device Installation Settings > select NO. Then reboot. Probably similar in Win 11. There's also another way to block WU from installing driver updates using the group policy editor (gpedit.msc), if the above doesn't stop WU from installing stuff we don't want/need. gpedit.msc is only available in Pro versions of Win 10 and 11, but not in Home versions.
All of a sudden, I am getting very slow upload speeds when using the ethernet cable (0.65 mbps), but normal speeds (10-11 mbps) when using wifi.  I have narrowed the problem down to the PC, not the router/modem.  On this PC, is the ethernet port part of the mother board?  All the drivers are updated.  I have a Killer E2400 GB Ethernet Controller and Qualcomm QCA9377 802.11AC wireless adapter.
XPS 8930, slow upload speeds, Ethernet port