I've had this system for about 1.5 years, but with Radeon RX 5700 (reference) instead of Radeon RX 550. It worked OK, and then about 2 weeks ago I sold my Radeon RX 5700 and replaced it with the Radeon RX 550.
After installing Radeon RX 550 I noticed that sometimes mouse cursor lags / stutters / "skips frames" when I move it. I thought that maybe I need to reinstall drivers, but that didn't help, and I ended up completely reinstalling Windows, which didn't help either.
I'm emphasizing this again: I had a system that worked OK, I replaced graphics card to Radeon RX 550, everything else is the same - same PC components, same peripherals, same cables connected to the same slots, same desk, same chair, everything connected to the same power socket, etc.
The issue with lagging mouse cursor is sporadic, it does NOT lag all the time. Sometimes it's OK, sometimes it's not.
I've also noticed that if I create some GPU load, e.g. run FurMark stress test, or even play video in a player that uses GPU for decoding / rendering, then GPU and GPU memory clocks rise (from 214 MHz to 1183 MHz and from 300 MHz to 1750 MHz respectively), PCIe bus interface also speeds up from x8 1.1 to x8 3.0 (according to GPU-Z) and the lag is gone. This is actually the workaround I've been using for the last 2 weeks to "fix" the issue: every time I boot my PC I start playing a movie in a loop, mute it, minimize the player window, and with the movie playing in background I can work normally without mouse lagging.
There is no other issues with my PC, everything works OK: audio and video playback (both in browser and in desktop player), typing on the keyboard, playing games, running stress tests - everything is OK, even without the "movie workaround". I've also tried to run Ubuntu 20.10 in live mode from USB, at there was NO issue with the mouse cursor lagging, so I guess that proves it's not a hardware issue.
I think it's some PCIe power saving issue in the graphics driver. I've tried settings PCIe ASPM in Windows power plan to OFF, and I think it reduces the frequency the lagging occurs, but I'm not 100% sure because, as I said, the lagging is inconsistent. In any case, even setting it to OFF doesn't fix the issue completely.
So the question is: what can I do to resolve the issue, or am I stuck with my "movie workaround" until I buy a new graphics card?
disable HDCP support in driver...
I tried to disable HDCP Support in Radeon Software, but it didn't help.
Actually, I noticed another "symptom" that might be related to the issue. After I rebooted my PC to apply the new HDCP Support setting, I went afk for a few minutes and when I returned I was "welcomed" by a window that said something about "driver timeout was detected", or something like that, and it suggested I report the issue to AMD. I actually saw that error a few times after installing Radeon RX 550, but I wasn't (and still isn't) sure if it's related.
mh, can be driver related - please report at amd.com/report ;)
also (in that order):
update Win10 to 20H2
disable Win10 auto-driver-install
use DDU in safe-mode to clean old driver
For those having this issue, you might wanna try using another DP cable, I had exactly the same issue with and RX550 too and a 2y old cable that worked flawlessly up until a couple of weeks ago. Banged my head with reinstalling drivers, dust cleaning the GPU cooler, disabling HDCP and whatnot. Until it hit me two days ago and went for a new cable. All smooth now. I guess the cable deteriorated over time, which is weird, because I have much older cables on various devices and no problems at all. Or maybe it had some "almost lose" contact from factory and now it cracked and was causing too many errors in communication, lowering the transfer rate significantly. My two cents