RTX 4090 + LG 45GS95QE-B 240Hz Ultrawide – Ongoing Microstutter / Latency Spikes (Done Everything – Seeking Final Input)

[louisdz]

Hey everyone,

I bought a top-end PC recently — RTX 4090, 240Hz ultrawide, Ryzen 7950X3D, clean setup.
But from day one it’s been stuttering like mad when I play games uncapped.

I’m talking about games like League of Legends, Apex, CS2 — nothing crazy.
As soon as I leave the FPS uncapped, the whole thing starts freezing or hitching every few seconds.
Even at 240Hz it stutters.
The only thing that kind of helps is capping the FPS in-game (RTSS didn’t help).

---

What I've Done:

• Reinstalled Windows clean
• Flashed the BIOS (F36)
• Clean installed GPU drivers (multiple versions: 580.88, 577.00, 537.58)
• Disabled G-SYNC, VRR, Adaptive Sync, Game Mode, HAGS, everything
• Tweaked NVIDIA Control Panel settings
• Tried HDMI and DisplayPort
• Used different cables, reseated GPU
• Disabled overlays, RGB software, startup apps, etc.
• Power plan set to High Performance
• RAM passes memory tests
• No thermal issues, no WHEA errors, system is cool and stable
• GPU runs at PCIe 4.0 x16, confirmed

---

Benchmarks and Testing Tools Used:

LatencyMon:
• DPC latency spikes from nvlddmkm.sys and wdf01000.sys
• Even when idle or on desktop with nothing running
• Screenshot (Win+Shift+S) causes GPU to boost and stutter
• System flagged as "not suitable for real-time audio tasks"

HWiNFO64:
• Confirmed PCIe 4.0 x16 link
• GPU core clocks boost correctly, but stay high at 240Hz even when idle
• VRM voltages, VDDCR, and power draw normal
• CPU and GPU temps stable (no thermal throttling)
• RAM voltage and temps normal (1.35V EXPO)

Windows Memory Diagnostic: Passed (no errors)

RTSS (RivaTuner):
• FPS capped at 240 / 235 / 220 / 200 / 140
• League’s in-game FPS cap smoother than RTSS
• Tried with and without RTSS overlay and scanline sync

PresentMon / Performance Overlay:
• Frame pacing issues confirmed
• FPS fluctuating 213–240 on desktop when uncapped
• No frame limiter = microstutters and inconsistent delivery
• At 120Hz: GPU finally drops to P8 idle, smoothest overall

OCCT Power Test (CPU + GPU simultaneous):
• Ran with large data set, extreme mode
• 30+ minutes, no errors
• CPU and GPU stayed stable under full load
• Temps were excellent (~47°C CPU average, ~30–40°C GPU)
• No system instability, no shutdowns, no clock drops

---

Confirmed:
• Power delivery is solid
• Cooling is working perfectly
• No hardware throttling
• No crashes or WHEA errors during stress test

---

What Still Happens:
• Random stutters mid-game (even at 144Hz)
• GPU clocks sometimes idle too high
• Stutter or latency spike during screenshot (Win + Shift + S)
• LatencyMon still shows spikes even when nothing is running
• Fans spin aggressively after screenshot or screen interaction

---

At this point:
I’ve done everything I could find on Reddit and forums — clean installs, driver swaps, BIOS tuning, overlays off, all the “known” fixes.

It makes zero sense. The system is top-end.
But games like League of Legends are stuttering more than they did on my old PC.

Have I been scammed or what is this?

Any advice or final suggestions? This is driving me mad and no post I’ve seen has fixed it.

If you've got a 4090 + ultrawide 240Hz setup that works smoothly — please reply.

[Bloods]

Since I didn't see it mentioned in your post, are you running games exclusively on the L3 Cache CCD ?

[ArkoN]

So first of all put your Power Plan to Balanced on this CPU, otherwise it will take the higher clocking NON X3D CPUs for some games as more MHZ it thinks = More Performance...

[dpcfucker]

have you been able to fix it? i have exactly the same issue.