Lenovo T14 Gen2 AMD - CRAZY High Latency - Am I screwed?

Hello All,

Im a first timer trying to setup linuxcnc and fairly new to linux in general.  Im hoping there is something im overlooking and my purchase wasn’t a waste but not optimistic…

I was originally going to get a Pi5 but price went from $80 to $130 locally just for the board that would have needed cost of case and screen on top of that.  Picked up the laptop below for $200 so it seemed like a sweet upgrade and saw what appeared to be success from other users on what seemed like similar hardware.  I understand that laptops are not ideal due to power saving settings built into them but I will be running a Mesa 7i96s so figured I could get away with it.  I wanted something with a bit more power as in a perfect world I WOULD like to be able to run fusion 360 on it (I know its not directly compatible) if I need to make simple tweaks to a program.  This would just save me carting around two computers.


Computer:
Lenovo T14 Gen 2 AMD
Ryzen 7 Pro 5850u (8c/16t 1.9ghz)
Radeon Integrated Graphics
16gb DDR4 3200
512gb SSD
Realtek RTL8111H-CG Ethernet


Installed LinuxCNC 2.9.8 Debian 13 Trixie PREEMPT-RT without major issue except it not finding network drivers itself.  Everything seemed to work ok but I installed r8168-dkms to hopefully prevent issues.  Get into the system and run the latency test.  Not getting any consistent results but from the latest run I got the following.

Latency Histogram Results with nobase – 2450 microseconds running 10 glxgears and a couple videos
Latency Test Results – Servo thread jitter 3,370,408ns 
Latency from laptop to Mesa card through a 3 ft cable is 0.857/0.891/0.937/0.014ms


Results seem crazy based on what I have read so I started following various peoples advice on tweaks.

Going through the BIOS its completely LOCKED down unfortunately.  There are basically no options other than security and boot options.  I went through and did everything I could but no ability to disable SMT or anything else that everyone recommended as first steps.

Walked through several videos on youtube from MrRodW on system and kernel tweaks and none of the tweaks seem to have a significant impact unfortunately.  I could get a little better but still miles off what people say is acceptable.

Changes made
Isolcpus – tried several combinations of multiple and single cpus
nohz_full – matched above changes
rcu_nocbs – matched above changes
intel_ideal.max.cstate=0
processor.max.cstate=1
idle=poll
cpupower frequency-set --governor performance

Checks:
uname -a = Linuxcnc 6.12.63+deb13-rt-amd64
latency-histogram – Note: Using POSIX realtime


So give it to me straight….  Am I screwed?

Thanks,
Looby

Not being able to access the bios seems quite a handicap. Lenovo says replace the motherboard. I found some possibilities otherwise:
www.ebay.com/itm/204768580473
and
www.reddit.com/r/thinkpad/comments/13wwp..._reset_for_t14_gen2/

Hope that helps.

Ill try the other release and see how it shakes out. Its killing me because I see the T470/T480 in use in that thread and this is just the newer version of that laptop. Also I figured I was safe because this one can be bought from Lenovo with Debian preinstalled.

Sorry to clarify the bios is not password locked its just extremely limited by the manufacturer. Locked down in terms of restricted to basics.

Well Ive spent all day trying other installs or live versions and no dice. Cant get any to run live as they just hang at a blank cursor screen. Cant even get anything installed due to a "bad archive mirror" error.

Tried latest regular Debian and got that installed and then followed directions to install linuxcnc and got it up enough to latency test aaaaaand 4,550,000ns....

What causes this so I have some idea what to avoid in the future? What in the hardware would cause this?

Like it could be a cooling issue? I guess I can pull the cooler off but the fans are barely spinning and fdoesnt feel warm at all.

Looby wrote:

Cant get any to run live as they just hang at a blank cursor screen.
[1]

Cant even get anything installed due to a "bad archive mirror" error.
[2]

What causes this so I have some idea what to avoid in the future? What in the hardware would cause this?
[3]
 
 

1. I'm currently fighting with a pc with that disease. It seams to be a GPU related issue. I've tried literally everything I can think of, no luck. Odd thing is, I have an identical machine at a client, running the same hardware on Debian just fine. I'm ready to try swapping out the brand new Gigabyte RTX4060 8GB graphics card with another one, beginning to think I might have hit a genuine hardware fault. I'm running various other 4060's and this is the only one doing this.

Might be a bit tough to get into any diagnostics on the live boot to see what is failing. In my case I was able to ssh into the pc from another machine right next to it so I could look at things like: "sudo dmesg", "sudo lspci -v", "sudo journalctl -b 0" and discover the gpu is not properly starting. That pc is booting an SSD with Debian already installed, with open-ssh running. I tried Nvidia drivers of several varieties.

I do not know what graphics your machine runs, it might not even be Nvidia.

2. First thing I check when I get that error: Is my pc's clock set correctly? Usually that is the problem. It does not have to be perfectly correct, but there is a limit to where security certificates fail to work. I open a terminal and:
check the date:
nwe@debian:~$ date
Mon Feb  9 04:39:11 AM CST 2026
set the date:
nwe@debian:~$ sudo date -s "Mon Feb  9 04:39:11 AM 2026"
[sudo] password for nwe: {typed my password and hit enter}
Mon Feb  9 04:39:11 AM CST 2026

3. I feel your pain. Some hardware/software combinations simply fail to work correctly. It seems there's a lot of hardware that 'just works'. In general, avoiding low end hardware and very very new hardware can save you lots of grief. Search the forums and buy something that is working, I mean exactly the same model and version, lands you a pretty good chance of success. But, as you can read in my #1 above, not even that is a guarrantee. Two identical machines. One just works. The other just doesn't.

I'm not pointing fingers at Linux saying this. My biggest letdown of all time regarding unexpected incompatibilities was on a proprietary os.

Sorry for not responding but Ive been trying other distributions (Mint, Ubuntu, and some wonky 3rd one I cant remember) hoping for better results and all end in either failed installs or crappy results.

I have another pc im hoping to try but havent gotten to it yet. Ill try the clock correction thing tomorrow and see if that yields anything better.