Monitor Tests Forum

ToastyX:

Sorry if this was asked before, but what exactly is the difference between driver "Default" timings and CRU default timings that have a lower HT and porch values?

Example: (at least on AMD) in windows,

The default timings for 1920x1080 for the Benq XL2720Z / 2420Z/2411Z are:

front porch 88 pixels, 4 lines
Sync width 44 pixels, 5 lines
Horizontal 2220, Vertical 1125.

Yet CRU uses these defaults for lightboost mode, for example:
front porch 48,3
sync width 32,5
Horizontal: 2080
VT (1138,1143 or 1149 for 100, 110 and 120hz lightboost).

Using the higher values works fine also without a problem for normal lightboost

However over a DISPLAYPORT connection, strange things start happening at a few specific custom refresh rates.

Certain specific custom resolutions / timings with the 2200 HT and 88 front porch timings will simply make the monitor shut off over displayport only, but not over DVI !

Some examples from my XL2720Z:

60hz lightboost (double strobe; just a curiousity):
2200 HT, 1155 VT, 60hz (this activates 60hz lightboost at 120hz strobe pulses on my XL2720Z, so it strobes twice per refresh)
Front porch 88/4
sync width 44/5

(note this does not work on the Asus VG248QE ! You need VT 1179 to get 60hz lightboost)

Displayport: monitor shuts off instantly.
DVI: no problem.

2080 HT, 48/3 front, 32/5 sync, 60hz, 1155 VT
Displayport: no problem.

50hz (custom resolution and VT required to enable benq blur reduction at 50hz with single strobe enabled; monitor will NOT strobe at all at default 50hz anything):

front porch 88/4, sync 44/5
HT 2200, VT 1360, 1920x1080@50hz

Displayport: monitor shuts off
DVI: works fine.

Front porch 48/3, sync 32/5
HT 2080, VT 1360, 50hz
no problem on DP, DVI.

Note: higher refresh rates like 100hz, 120hz, 85hz, etc work fine with the 2200 HT, etc and VT 1500.

When I updated my graphics card drives (AMD 15.7) I can't overclock my monitor without it becoming blurry.

(08-21-2015 03:14 AM)bestservedcold Wrote: [ -> ]When I updated my graphics card drives (AMD 15.7) I can't overclock my monitor without it becoming blurry.

That doesn't tell me anything. What monitor are you talking about? What resolution and timing parameters are you trying to use? Are you using DVI, HDMI, or DisplayPort? Did you use the pixel clock patch? If so, did you reapply the patch after updating the driver?

(08-20-2015 08:44 PM)falkentyne Wrote: [ -> ]ToastyX:

Sorry if this was asked before, but what exactly is the difference between driver "Default" timings and CRU default timings that have a lower HT and porch values?

I don't know what you mean by default. The monitor defines the timing parameters in the EDID. The driver gets the timing parameters from the monitor. CRU shows what the monitor defines and lets you override that.

(08-20-2015 08:44 PM)falkentyne Wrote: [ -> ]Example: (at least on AMD) in windows,

The default timings for 1920x1080 for the Benq XL2720Z / 2420Z/2411Z are:

front porch 88 pixels, 4 lines
Sync width 44 pixels, 5 lines
Horizontal 2220, Vertical 1125.

Those are the CEA standard timing parameters for 1920x1080 @ 30/60/120 Hz. CRU uses the same timing parameters for "LCD standard" at 1920x1080 @ 30/60 Hz and for "LCD native" at all refresh rates.

(08-20-2015 08:44 PM)falkentyne Wrote: [ -> ]Yet CRU uses these defaults for lightboost mode, for example:
front porch 48,3
sync width 32,5
Horizontal: 2080
VT (1138,1143 or 1149 for 100, 110 and 120hz lightboost).

CRU doesn't have the LightBoost modes programmed into it. Strobelight uses those timing parameters because that's what I determined was being used when NVIDIA's driver activated 3D mode with the ASUS VG248QE. Those are just the CVT-RB standard timing parameters with the vertical back porch/blanking/total increased by 5.

CRU uses CVT-RB for "LCD standard" at 1920x1080 @ 120/110/100 Hz, which also matches what the ASUS VG248QE defines for those refresh rates. Are you saying the BenQ defines something different?

Thanks,, ToastyX.

Quote:CRU uses CVT-RB for "LCD standard" at 1920x1080 @ 120/110/100 Hz, which also matches what the ASUS VG248QE defines for those refresh rates. Are you saying the BenQ defines something different?

Yes but this is at 60hz.
On a FRESH driver install, after a full reset (or you can run reset all in CRU), the following line exists in detailed resolutions on the Benq XL2720Z: :

1920x1080@60
Front: 88/4
Sync: 44/5
HT 2200
VT: 1125

Are you saying that this is only for 60hz and not for 100, etc? (I have no way of knowing what's shown for 100/110/120 etc).

What I do know is, for the 60hz above:
Over DISPLAYPORT:
If I change the 1125 VT to 1155 VT, the monitor just shuts off.
Over DVI, it doesn't.

But if I change the timings to CVT-RB so it has the 2080 HT, then it activates lightboost mode double strobed.

I attached a screenshot after using reset-all.

I'm guessing then that the displayport "Loss of signal" issues with some of the custom timings are simply a firmware problem.

I know that V4 firmware (according to someone that emailed Benq about their V3 monitor losing signal on DP (and only on DP) and they getting RMA'd and shipped back a V4 from Benq Europe) and they replied back to them) officially fixed displayport loss of signal problems whenever the monitor went to sleep. I guess not "all" of the bugs were fixed, then.

(08-21-2015 10:36 AM)falkentyne Wrote: [ -> ]On a FRESH driver install, after a full reset (or you can run reset all in CRU), the following line exists in detailed resolutions on the Benq XL2720Z: :

1920x1080@60
Front: 88/4
Sync: 44/5
HT 2200
VT: 1125

Are you saying that this is only for 60hz and not for 100, etc? (I have no way of knowing what's shown for 100/110/120 etc).

Most monitors use those timing parameters for 1920x1080 @ 60 Hz, including the ASUS VG248QE. Strobelight also uses those timing parameters for 60 Hz. Most 120 Hz monitors use CVT-RB for 120/110/100 Hz. You can see what the BenQ defines in the extension block by running reset-all.exe and restarting, and then use GetEDID or MonInfo to save the full EDID to a file that you can import into CRU.

(08-21-2015 10:36 AM)falkentyne Wrote: [ -> ]What I do know is, for the 60hz above:
Over DISPLAYPORT:
If I change the 1125 VT to 1155 VT, the monitor just shuts off.
Over DVI, it doesn't.

But if I change the timings to CVT-RB so it has the 2080 HT, then it activates lightboost mode double strobed.

I'm pretty sure LightBoost is supposed to use the CVT-RB 2080 HT, not the CEA 2200 HT.

Hello there!

I'm having some issues with certain resolution / hz, and hopefully you guys can help me out.

I'm using Samsung SyncMaster T240, which uses native resolution 1920x1200 @ 60Hz

I saw in the monitor manual that I can use lower resolution at higher vertical frequency, and thought it would be useful for playing FPS games on my computer.

So I've decided to make a custom resolution 1280x1024 @ 75.025 Hz in CRU, since it doesn't allow me to select anything above 60 Hz when I right click on desktop -> Screen Resolution -> Advanced settings -> Monitor -> Screen refresh rate


I open up CRU, go to Detailed resolutions, click Add, select Manual Timing, I've entered 1280 x 1024 and 75.025 Hz, but the Horizontal Frequency and Pixel clock values are completely different than the ones on the monitor manual, and I can't change them all, since they correspond to each other -> CRU setting

So the manual says I should use:
75.025 Hz, 79.976 KHz, 135 Pixel Clock Mhz

And the CRU / monitor uses:
75.025 Hz, 79.458 Khz, 114.42 Pixel Clock Mhz

When I select this resolution on desktop ( or in game ), it apparently works at 75 Hz, but the monitor shows the message which says:

Not Optimum Mode
Recommended Mode :
1920 x 1200 60Hz

I can cancel the message once, but the monitor turns black after about a minute. It seems to do it everytime I set it to 75 Hz, even though it supports it.

Is there anything I can try?

I'm using Sapphire Radeon 7850 OC and Windows 7 x64.

I've also tried using PowerStrip, but it's outdated ( doesn't officially support Windows 7 ) and it doesn't allow me to use any custom resolution ( it is greyed out )

Any ideas would be greatly appreciated.

(08-23-2015 01:23 PM)TuN Wrote: [ -> ]I'm using Samsung SyncMaster T240, which uses native resolution 1920x1200 @ 60Hz

I saw in the monitor manual that I can use lower resolution at higher vertical frequency, and thought it would be useful for playing FPS games on my computer.

So I've decided to make a custom resolution 1280x1024 @ 75.025 Hz in CRU, since it doesn't allow me to select anything above 60 Hz when I right click on desktop -> Screen Resolution -> Advanced settings -> Monitor -> Screen refresh rate

The manual might be wrong, or it might only accept higher refresh rates with VGA. If the monitor supported those resolutions, they should be available by default. Make sure GPU scaling is disabled.

(08-23-2015 01:23 PM)TuN Wrote: [ -> ]I open up CRU, go to Detailed resolutions, click Add, select Manual Timing, I've entered 1280 x 1024 and 75.025 Hz, but the Horizontal Frequency and Pixel clock values are completely different than the ones on the monitor manual, and I can't change them all, since they correspond to each other -> CRU setting

So the manual says I should use:
75.025 Hz, 79.976 KHz, 135 Pixel Clock Mhz

And the CRU / monitor uses:
75.025 Hz, 79.458 Khz, 114.42 Pixel Clock Mhz

Many of the lower resolutions in the manual correspond with the list of established resolutions. Try using the 1280x1024 @ 75 Hz under established resolutions. That should give the VESA standard timing.

For detailed resolutions, CRU doesn't have the VESA standard timing programmed into it, but you can enter it manually: http://tinyvga.com/vga-timing/1280x1024@75Hz

You'll have to enter 75.024 Hz because it's really around 75.02467 Hz. Samsung monitors usually aren't picky about the timing parameters, so if that doesn't work, then the monitor isn't allowing higher refresh rates.

Well I have tried VGA, Hdmi and Double-link DVI, same issue on all of them.

How do I enter this:

Screen refresh rate 75 Hz
Vertical refresh 79.976303317536 kHz
Pixel freq. 135.0 MHz


I can only select one of them, and then the other two settings correspond to the one that I have manually entered. I can't enter all three myself, unless there is a way that I'm not aware of.

EDIT: I have manually changed the Visible area, Front porch, Sync pulse and Back porch, and now it does adjust the Vertical refresh and Pixel frequency to the values that are mentioned in the manual. I'm rebooting then testing it.

EDIT 2: It doesn't work. I tried again with VGA and DVI and also the established resolution, but i still get the warning on the monitor OSD.

I just don't get it why does monitor work at 1280x1024@75Hz, but still keeps turning black after a while. It should either work or it just shouldn't. It's like the monitor is just teasing me with showing that it actually works and then turns black

I'll get the 144Hz monitor some day or even Korean 2560x1440 monitor and overclock it, but I wanted this monitor to last a bit more. The 75 Hz does make a difference over 60 Hz :/

Hi all, im kinda newbie in this. I have AOC 2236swa 21.5 inch, native resolution 1920x1080 @60hz, that has only VGA. I would rly like to run it on faster refresh 72,75 but my monitor can do it only on lower resolution. I managed to make custom resolution in CRU, but the picture is always off alot (pushed to the left so i see only half of display). Im googling alot but i rly dont know what else to do now. Help me pls or tell me if u need more info. ty in advance