I recently bought the Acer Predator XB273U F5 (immediately updated to firmware version 1.1.4) and although I’m generally very happy with it and the motion clarity it provides, I wanted to share some feedback:
Refresh Rate Capping (Single Monitor)
When G-SYNC Pulsar is enabled, the monitor’s refresh rate caps itself at around 320–321 Hz in-game, even if V-Sync is disabled and frame rates are comfortably higher (322 FPS and beyond).
- It doesn’t matter whether in-game Reflex is set to ON, ON+BOOST, or OFF.
- It doesn’t matter whether NVCP Low Latency Mode is set to ON, OFF, or ULTRA.
- It doesn’t matter if V-Sync is disabled in-game and forced OFF in NVCP.
Behavior With Second Monitor Connected
When a second monitor is connected, G-SYNC Pulsar caps the refresh rate to the intended maximum 360 Hz (as long as you’re above 360 FPS in any game). From that point on, G-SYNC Pulsar behaves normally, just like any other “vanilla G-SYNC” monitor.
Render Latency Measurements
(Aimbeast, UE4 title with Reflex available, RLAT via Nvidia app)
- V-Sync OFF: >1200 FPS consistently, ~0.5 ms render latency.
- V-Sync ON: Caps FPS to 360, eliminates tearing, render latency rises to 4.5 ms.
- V-Sync ON + NVCP LLM ON: Keeps 360 FPS, reduces latency to 2.7 ms.
- V-Sync ON + NVCP LLM ULTRA: Caps refresh rate and FPS to 327, latency ~0.5 ms.
- V-Sync ON + Reflex ON/ON+BOOST: Caps refresh rate and FPS to 327, latency ~0.5 ms.
As soon as the second monitor is disconnected, the Pulsar caps itself again at 320–321 Hz in-game, even if V-Sync is disabled and FPS are higher. Render latency remains ~0.5 ms with V-Sync OFF.
However, enabling V-Sync changes things drastically:
- V-Sync ON: Caps refresh rate and FPS to 321, eliminates tearing, latency jumps to 5.4 ms.
- V-Sync ON + NVCP LLM ON: No effect, still capped at 321 Hz/FPS, latency remains 5.4 ms.
- V-Sync ON + NVCP LLM ULTRA: Still capped at 321 Hz/FPS, latency reduced to 3.1 ms.
- V-Sync ON + Reflex ON: Still capped at 321 Hz/FPS, latency ~4.7 ms.
- V-Sync ON + Reflex ON+BOOST: Still capped at 321 Hz/FPS, but latency fluctuates erratically between 1.4 ms and 5.2 ms, second to second.
Introducing an FPS cap of 310 (either in-game or externally via RTSS Async) brings render latency back down to 0.5 ms. There is no tearing even with V-Sync OFF, because Pulsar remains engaged and working within its VRR range.
You can also push the FPS cap low enough to trigger the “Pulsar Low FPS” limit. In my case, that limit is set to 75, but the practical threshold is 79. As soon as I step down to 78 FPS, Pulsar very noticeably disengages. The difference in motion clarity is incredibly obvious — Pulsar really works wonders at such low framerates.
All of the above behaviors are reproducible in every game I tested that is not hard-locked to 60 FPS natively.
Test Environment
Tested with an RTX 5090 using the latest available drivers (596.21) on Windows 11 25H2 (OS Build 26200.8246).
If I can provide any more information that would be useful, please let me know.
Cheers!
/Edit1:
- Out of curiosity, I tried overclocking the monitor's refresh rate and discovered that my unit will go up to 587 Hz. Which is nuts, to be honest! However, doing so effectively disables both Pulsar functionality and VRR.
- I also found that overclocking the panel to 363Hz is as far as my unit will go while still maintaining Pulsar functionality and VRR.
- Screenshot 2026-04-21 093331.png (20.25 KiB) Viewed 4470 times
- Screenshot 2026-04-21 100139.png (58.34 KiB) Viewed 4470 times
DISCLAIMER
The information presented here is based solely on my personal experiences with this monitor. It is provided for informational purposes only and should not be interpreted as professional advice, guidance, or a recommendation. Any actions you choose to take based on this content are entirely at your own risk. I assume no responsibility or liability for any damage, loss, or issues that may arise from attempting to replicate or apply the methods, settings, or experiments described.
This page is a work in progress. I will continue updating it with observations, quirks, and interesting findings as I explore the monitor further. Please treat this as a personal log rather than a technical manual, and always exercise caution when making adjustments to your own equipment.
