What is Ultra-Low Motion Blur (ULMB 2)? The NVIDIA Technology Explained
Key Takeaway
- Fixes persistence blur: ULMB 2 turns off the monitor's backlight while the pixels are changing color, only flashing the light when the frame is perfectly rendered.
- Effective Motion Clarity: By eliminating sample-and-hold blur, a 360Hz monitor with ULMB 2 enabled provides the visual clarity of a 1000Hz+ monitor without strobing.
- Full brightness strobing: Unlike older strobing tech that made the screen incredibly dim, ULMB 2 delivers over 250 nits of brightness while strobing.
- Requires high framerates: To avoid visible flickering, you must maintain a framerate that matches your monitor's maximum refresh rate (e.g., 360fps for a 360Hz monitor).
If you play competitive shooters like CS2 or Valorant, you know that raw refresh rate is only half the battle. Even on a blazing-fast 360Hz monitor, fast-moving targets can still look slightly smeared. This is due to "sample-and-hold" blur—the blur created by your own eyes tracking an object across static frames. To fix this, NVIDIA introduced Ultra-Low Motion Blur 2 (ULMB 2). Let's explore how this technology achieves CRT-like motion clarity on modern LCD panels.
The Problem: Pixel Transition Visibility
On a standard LCD monitor, the backlight is always on. When a pixel changes from red to blue, it takes a few milliseconds to make that transition. Because the backlight is on the entire time, your eye sees the pixel in its "in-between" state (purple). This is what causes ghosting and smearing.
Older Backlight Strobing technologies (like ULMB 1 or DyAc) tried to fix this by turning the backlight off during the transition. However, they were flawed. They often strobed before the pixels were fully ready, causing double-images (crosstalk), and they drastically reduced the monitor's brightness, making it hard to see enemies in dark corners.
How ULMB 2 Changes the Game
NVIDIA's ULMB 2 solves the problems of older strobing technologies through a combination of panel hardware requirements and advanced G-Sync module processing.
1. Full Refresh Rate Strobing
Older tech often strobed at a lower frequency than the monitor's max refresh rate. ULMB 2 strobes at the exact maximum refresh rate of the panel (e.g., 360 times per second on a 360Hz monitor). This high frequency makes the flickering completely invisible to the human eye, reducing eye strain.
2. Vertical Dependent Overdrive
Because LCD panels draw frames from top to bottom, the pixels at the top finish transitioning before the pixels at the bottom. ULMB 2 uses the G-Sync module to precisely control the overdrive voltage based on the pixel's vertical location. This ensures that every single pixel on the screen finishes its transition at the exact same microsecond.
3. The "Flash"
Once every pixel is perfectly in place, ULMB 2 flashes the backlight on for a fraction of a millisecond, and then immediately turns it off again. You only see the perfect frame, with zero transition blur.
Effective Motion Clarity (The 1000Hz Claim)
NVIDIA claims that a 360Hz monitor with ULMB 2 provides over 1000Hz of "Effective Motion Clarity." This isn't just marketing fluff; it's based on math.
Motion blur is dictated by how long a frame is visible (persistence). At 1000Hz without strobing, a frame is visible for 1 millisecond. With ULMB 2 on a 360Hz monitor, the backlight is only flashed for about 1 millisecond per frame. Therefore, the amount of time the image is "held" on your retina is identical to a 1000Hz monitor, resulting in identical motion clarity.
Frequently Asked Questions
Can I use ULMB 2 with G-Sync/VRR enabled?
No. Backlight strobing requires a perfectly fixed, predictable refresh rate to time the flashes correctly. You must disable G-Sync/FreeSync to enable ULMB 2.
Does ULMB 2 reduce brightness?
It reduces brightness compared to the monitor's absolute maximum, but ULMB 2 requires panels to hit at least 250 nits while strobing, which is significantly brighter than older strobing tech.
Do I need an NVIDIA GPU for ULMB 2?
Yes, ULMB 2 is a proprietary technology that requires an NVIDIA graphics card and a monitor with a physical NVIDIA G-Sync module inside.
What happens if my FPS drops below my refresh rate with ULMB 2?
If you are playing at 360Hz but your FPS drops to 200, the monitor will strobe the same frame twice. This causes a severe "double image" or stuttering effect. You must maintain FPS equal to your Hz.
Is ULMB 2 better than OLED?
For pure motion clarity, a 360Hz LCD with ULMB 2 is currently clearer than a 240Hz or 360Hz OLED without BFI (Black Frame Insertion). However, OLED still wins in contrast and color.
How do I test if my strobing is working?
Enable ULMB 2, then use our Refresh Rate Test below. Track the moving objects with your eyes; they should look perfectly sharp, like a printed photograph moving across the screen.
Ready to test your monitor's raw motion clarity?
Is your monitor performing as advertised?
Don't just trust the box. Verify your true refresh rate and check for frame skips.
Run the Refresh Rate Test NowRefreshRateTest Engineering Team
A specialized collective of display hardware researchers and low-latency engineers dedicated to providing objective performance metrics for the high-refresh rate era.