How do I enable 60hz ULMB?

rasseru · Post by **rasseru** » 06 Apr 2018, 08:04

As title, I am trying out this monitor and dont have an .inf - it isnt for download easily on the website, i;ve tried to google and can only get the non-165hz model.

afaik I need to have the inf to get the correct timings with CRU? i'm trying to see if I can get 60hz ULMB working

cheers for any help

lexlazootin · Post by **lexlazootin** » 06 Apr 2018, 13:14

You don't need the INF file (to be honest i don't even know what that would be for) all of the resolutions are in the extension block of CRU, but it might be easier to do it in the NVCP. you want to edit a 100hz resolution and change it to 60hz and raise the VT so the pixelclock stays the same.

YouTube · Post by **Chief Blur Buster** » 06 Apr 2018, 14:45

rasseru wrote:afaik I need to have the inf to get the correct timings with CRU? i'm trying to see if I can get 60hz ULMB working

No.

No INF needed.

I've never needed an INF file for 60Hz ULMB hack.

Instructions (brand new, 2018-04-06)
60 Hz ULMB Hack

ToastyX creates the stuff completely from scratch.

Don't use Google for CRU instructions.
Currently, Blur Busters is the only place on the Internet with good CRU instructions & successful ULMB 60Hz hack instructions.

One theoretical possibility is that PG278QR isn't compatible with the ULMB 60Hz hack, but I know the 240Hz one definitely is. But that's probably not the problem since you probably haven't yet followed the Option A / Option B workflows yet -- but let us know.

Please let me know if my new HOWTO helps you!

lexlazootin · Post by **lexlazootin** » 07 Apr 2018, 00:16

>Not all older 144 Hz GSYNC monitors support the 60 Hz ULMB hack.

Did you check that it wasn't just the HT that was unlocked? My Acer 240hz has it's VT unlocked but with my old Benq 144hz (one of the oldest g-sync) has it's HT unlocked.

rasseru · Post by **rasseru** » 07 Apr 2018, 05:11

I followed your guide exactly (thanks btw) and whenever I go to 60hz mode ULMB turns off. And now i'm getting MAJOR STUTTERS warning in all modes on your test

120fps doesnt show when i'm at 120hz, getting double images, stutters

Not sure what is going on

PG278QR can support this mode? Can you confirm - it is some user error on my part?

Website · Post by **RealNC** » 07 Apr 2018, 05:58

Even though in theory Chief's guide should give the same results, it might be worth trying the alternative steps described here:

viewtopic.php?f=4&t=3501

In reality it's the same end result, but you never know. Before you begin, run reset-all.exe and reboot though to bring all the settings back to defaults first.

rasseru · Post by **rasseru** » 07 Apr 2018, 06:26

RealNC wrote:Even though in theory Chief's guide should give the same results, it might be worth trying the alternative steps described here:

viewtopic.php?f=4&t=3501

In reality it's the same end result, but you never know. Before you begin, run reset-all.exe and reboot though to bring all the settings back to defaults first.

I tried that one first and didnt work. i'll give it another go but something went screwy because of all the loss of sync on the website test.

Removed monitor driver and rebooted and now back to working ok at 120hz

YouTube · Post by **Chief Blur Buster** » 07 Apr 2018, 08:30

Use ToastyX reset-all.exe to clear all custom modes.

Did you try both monitors?

Don't use two monitors simultaneously running at different Hz, that interferes with TestUFO stutters.
(Unless it is the Primary)

Also, try the Acer?

rasseru · Post by **rasseru** » 07 Apr 2018, 09:00

The acer is in the box to keep it safe, i'll have to do it later.

The monitor makes the 'bing bu-lu bing?' sound, then flashes then, goes 'bu-lu-ling...' like a usb has bee plugged in, then taken out - is that normal?

Also, how does CRU exactly work - its at 85hz so the ULMB is on, but '85hz' mode is actually 60hz instead?

i think it almost worked but it was showing as 59hz in monitor display and there was annoying scanlines

Also, shame there isnt a 120hz half mode or something, so its 120hz but halved properly so no double image

YouTube · Post by **Chief Blur Buster** » 07 Apr 2018, 10:26

rasseru wrote:Also, shame there isnt a 120hz half mode or something, so its 120hz but halved properly so no double image

That is exactly what properly-set-up ULMB 60 Hz is.
Too bad it is an undocumented mode,

I wonder if the specific monitor firmware is preventing this hack on this specific monitor.

Does picture come back on when you disable ULMB?
If so, try decreasing ULMB Pulse Width to 50% before turning back on.

CRU works by allowing you to add undocumented video modes, and is commonly used for creating modes that the monitor doesn't come factory-preset with. It is popular for custom resolution and custom refresh rates. Unfortunately, not all monitors like them.

59Hz is probably closer to 59.94 Hz.... precise refresh rate is www.testufo.com/refreshrate or www.vsynctester.com

But yours is exhibiting an unusually strange behavior. Try avoiding locking Pixel Clock while following RealNC's instructions, and converging on that. Mybe also make sure Horizontal Total stays at 2080 for 1440p monitors. I may need to refine my instructions slightly to improve success rates. If others find a way to reliably get a PG278QR to sync to 60Hz ULMB, let me know.

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