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XPS 8950, USB undervolted
XPS 8950
Hi All.
[XPS 8950, Win11] I am using an old KVM switch (Trendnet TK-222DVK). It has external power. I have never had issues with it before on other machines. On my new XPS 8950, however, I am having intermittent problems. Sometimes I get the Win11 popup error "USB device not properly detected". Sometimes the KVM is properly detected at boot. Sometimes the KVM gets dropped after a wake/sleep cycle or KVM toggle. The KVM itself might be failing. However, observing the lights on the KVM suggests that the XPS 8950 USB might be undervolted at boot and/or wake/sleep cycles. I have turned off all power saving USB options in the Device Manager. This KVM does not have a driver. It is a simple USB passthru. I have tried all USB ports on my XPS.
I have ordered a new KVM, but this seems to me like either a hardware, a BIOS or an OS issue related to my XPS.
Has anyone else experienced similar intermittent USB issues on their XPS?
Tesla1856
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September 24th, 2022 11:00
1. Well, AFAIK ... it can be under-volted/under-amped if your USB-device has it's own external power.
2. For now, I would suggest you temporarily disable Sleep and/or Hibernation. Turn computer On to use it, turn if Off at night.
3. Good. I assume it's USB-v3.0 capable. I was going to suggest you try the other USB-v3.0 ports and they are likely broken-up into a couple of different internal USB-Hubs/Controllers.
4. Yes, others have reported various USB and networking communication and Latency problems, as they come fresh from factory. Hard to say exactly what is causing it as I don't own the particular model.
Because the KVM has to handle all keyboard/video/mouse data ... seems like total-bandwidth and Latency of the USB port would be important.
Most were fixed by uninstalling Intel Killer Performance Suite. This is from my notes:
I've found that you can simply uninstall Intel Killer Performance Suite from Control-Panel/Programs-Features, and then reboot . I found that all the Killer/xTend Services were also properly uninstalled (but you should probably double-check for lingering Services anyway). The base ethernet Network Interface Card drivers are left in place and the NIC still works fine (actually, usually better than before as it's a leaner/simpler configuration).
Recent threads are here:
https://www.dell.com/community/XPS-Desktops/8950-Continuous-Audio-Dropouts/td-p/8273097
and here
https://www.dell.com/community/XPS-Desktops/Slow-quot-uploads-quot-with-xps8950-using-ethernet-connection/m-p/8274638#M75594
and more Latency issues here
https://www.dell.com/community/XPS-Desktops/XPS-8950-quot-hiccups-quot-with-audio-and-video/td-p/8169744
(I think some of these DAW-users are using external USB audio interfaces on their XPS-8950/8940).
Uninstalling Support Assist is another thing that fixes various problems. We have seen that for a while now over the years. Seems it's depended on various Processes and Services and tends to get overly-needy as it tries to monitor everything.
Personally, on my (similar) Aurora-R6 ... I don't run Support-Assist, Dell/Alienware Update, Intel Killer Performance Suite ... or really any of that kind of "enhanced driver-suite" and/or Dell stuff. Provides a leaner install and everything just seems to work (including networking and various external USB peripherals).
Tesla1856
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October 1st, 2022 09:00
1. Excellent. Good work.
2. Agreed. But this is just Rivet's (now Intel's) enhanced-driver software that has always been troublesome (for like 10 years now). It "fixes" a problem that didn't exist in the first place. Network-Performance-Killer is a good name for it.
3. Agreed. In BIOS, turning-off "UEFI Capsule Updates" should limit or prevent that in the future.
4. Minimal drivers or just using the leaner/simple audio driver that Windows tosses you is usually good. Also, these are nice. It's a whole new "sound-card" that converts any analog speaker-set or headphone to digital.
Vic384
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September 23rd, 2022 17:00
@BrendanMMDD So it appears to me that the KVM switch acts like a USB hub for all the connected USB devices, the keyboard, mouse, and two other USB devices. Depending upon the number of USB devices you have connected they may not be able to be powered by the computer's USB port assuming that the hub in the KVM switch is not a powered USB hub. Without the KVM switch, your USB devices would each have their own USB port. Do you know if the USB hub in the KVM switch is a powered hub?
BrendanMMDD
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September 25th, 2022 04:00
Thanks for all that information!
During the boot process, it is evident the xps uefi picks up and drops the usb to the kvm and then tries to detect it again as windows loads. I wish there was a list of Dell Approved kvm as both my work laptop and desktop are Dell. I wasted $150 on a dual usb-c kvm (Sabrent USB-KCPD) only to find it cropped/windowed the video signal from my Dell dock. (I also found out that the usb-c on the xps 8950 did not carry video, but that was my ignorance of usb-c.). I will be testing another kvm (TESmart HKS0201A2U) this week. I will report back in this thread.
Tesla1856
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September 25th, 2022 08:00
Not sure how much of that is fairly normal for a USB-based KVM. My last (old) KVM had separate video cables (ie switched separately, but concurrently of course).
I'm surprised the Sabrent unit didn't work properly as their stuff is usually highly compatible.
BrendanMMDD
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September 25th, 2022 08:00
I opened a ticket with Sabrent but they asked me to send pictures of how I hooked up the dock and wanted me test without the dock i.e. directly in the laptop. I closed the ticket. I am not their Q&A and failed to see a possible solution to what was obviously hardware incompatibility. It could be an issue with the dock, but the dock is from work and I would never get permission to update/flash the dock firmware. Stupid me for prematurely throwing out the Sabrent packaging and receipt. I know better. The old kvm does have external power. Plugging in external power to it was my attempt at debugging when I started having issues.
The TESmart kvm I bought is standard dual HDMI. I am optimistic it will work.
Tesla1856
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September 25th, 2022 17:00
I was intrigued by your questions and usage of KVM. So, while we wait ... I hope it's ok if we exchange ideas here?
Like I said, I used to have a cheap KMV-switch-box (back in the days of VGA ... and video was separate). Back then I used it to work on client's computers brought back to the shop for service. I also had a Windows Server-2000 running and would switch to it. Needless to say, I haven't done either of those things in many years.
However, if I did want to hook-up a stray PC nowdays ... I would just use the un-used HDMI cable that I have pre-connected (on one end) to my Dell UltraSharp u2410 monitor. Then just grab a spare keyboard and mouse from the closet.
So, on my desk I have two Dell UltraSharp Monitors. As you likely know, they have many different Inputs available. I have my Aurora-R6 hooked-up-to both. I can use either or both (extended desktop).
My Mac-Mini is tucked behind them on my desk. It is also connected to both. It has Bluetooth wireless keyboard and mouse. Same here ... I can use either as main or even both concurrently.
What's also nice it that I have the left monitor (normally considered the secondary one) to "Auto-Detect Input" and I don't even have to touch it's menu-button when I drop-back to one monitor on the Aurora-R6 Windows and fire-up the Mac-Mini. It just appears on the screen.
So anyway, between the above and using programs like RDC and Ultra-VNC (to my other machines, some headless) I seem to have removed the need for a KVM. Just some ideas for you or others trying to do similar things as us.
BrendanMMDD
9 Posts
1
October 1st, 2022 08:00
Hey. Well. Ever since I prohibited my computer from sleeping and uninstalled Intel Performance Killer I have been able to keep using my old kvm switch, so who knows when I will get around to testing the new one. I have lost all motivation! I don't have a very flexible office space at home; your setup sounds like a dream. Eventually I will get a proper desk, a proper chair, and a better monitor with a proper mounting system, but I hate shopping (even online) so badly that buying stuff is always my last priority.
I wish Dell would stop adding all this crapware to their computers. Dell assembles some truly beautiful hardware. I love the XPS and at work we use precision desktop servers which are wonderful designs. But this crahpware is frustrating. I was shocked when a windows update automatically flashed my uefi without warning. Add some day I'll figure out why my onboard audio crackles so much, especially, when alt-tabbing. Or I will outsource the audio processing via usb dsp speakers. Good hardware. But the base windows config and crahpware are a test of patience.
BrendanMMDD
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October 4th, 2022 05:00
It is powered. That was the first fix I tried was going searching a box of odds and sods and digging out a compatible DC adapter.
Edit: Oops. Time delayed response due to middle age...
BrendanMMDD
9 Posts
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October 7th, 2022 04:00
Thanks for all your help. I have bookmarked this page for future reference. Just had EUFI updated to 1.6.0 and then I turned off capsule updates. While in the EUFI I noticed USB settings under Power Options related to S4/S5 states and normal sleep. Do you have a link to the EUFI documentation so I can try to understand these settings. They read like they could be part of the USB problem.
Another curiosity. The 1.6.0 EUFI notes state:
"- Fixed the issue where an unexpected warning message is displayed when a USB Type-C device is connected."
I was getting this warning from a non type-C port, and was also getting a message that my machine kept losing the USB signal to my UPS when I unplugged and plugged back in my KVM USB, so I would say the issue is/was a lot deeper than just type-C. It smells like a hub issue. I hope 1.6.0 addresses the issue but now that my machine is working I am reluctant to twiddle with it. Two dew claws down for making me disable sleep and waste carbon to get my KVM switch to work. So forked up...