# Incorrect definition of pixel clock. 390.141
**URL:** https://forums.developer.nvidia.com/t/incorrect-definition-of-pixel-clock-390-141/170159
**Category:** Linux
**Tags:** hdmi
**Created:** [March 5, 2021, 3:37pm UTC](https://forums.developer.nvidia.com/t/incorrect-definition-of-pixel-clock-390-141/170159 "2021-03-05T15:37:11Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@blancodima](https://forums.developer.nvidia.com/u/blancodima)
#### Post date: [March 5, 2021, 3:37pm UTC](https://forums.developer.nvidia.com/t/incorrect-definition-of-pixel-clock-390-141/170159/1 "2021-03-05T15:37:11Z")
Greetings
In short, the nvidia driver has a maximum pixel clock of 225 MHz, and I can’t apply my screen resolution. But on the nouveau driver everything works correctly, the maximum pixel clock is 305 MHz.
My monitor supports a resolution of 2560x1440@60 (241.50 MHz Pixel Clock) Connected via **hdmi**
I don’t have this screen resolution in GUI (nvidia-settings), so I added a new mode via xrandr, but I got an error when adding it. The fact is that for some reason, the system does not accept a resolution that has a pixel clock higher than 225 MHz. And I can’t understand why the maximum frequency of 225 Mhz is set in the parameters.
My resolution setup:
> $ cvt -r 2560 1440
> # 2560x1440 59.95 Hz (CVT 3.69M9-R) hsync: 88.79 kHz; pclk: 241.50 MHz
> Modeline “2560x1440R” 241.50 2560 2608 2640 2720 1440 1443 1448 1481 +hsync -vsync
When I try to set the resolution, `/var/log/Xorg.0.log` says:
> [723.943] (WW) NVIDIA(GPU-0): Validating Mode “2560x1440R”:
> [723.943] (WW) NVIDIA(GPU-0): Mode Sources: User Specified, RandR Specified
> [723.943] (WW) NVIDIA(GPU-0): 2560 x 1440 @ 60 Hz
> [723.943] (WW) NVIDIA(GPU-0): Pixel Clock : 241.50 MHz
> [723.943] (WW) NVIDIA(GPU-0): HRes, HSyncStart : 2560, 2608
> [723.943] (WW) NVIDIA(GPU-0): HSyncEnd, HTotal : 2640, 2720
> [723.943] (WW) NVIDIA(GPU-0): VRes, VSyncStart : 1440, 1443
> [723.943] (WW) NVIDIA(GPU-0): VSyncEnd, VTotal : 1448, 1481
> [723.943] (WW) NVIDIA(GPU-0): Sync Polarity : +H -V
> **[723.943] (WW) NVIDIA(GPU-0): Mode is rejected: PixelClock (241.5 MHz) too high for**
> **[723.943] (WW) NVIDIA(GPU-0): Display Device (Max: 225.0 MHz).**
> **[723.943] (WW) NVIDIA(GPU-0): Mode “2560x1440R” is invalid.**
> [723.943] (WW) NVIDIA(GPU-0):
When the nvidia driver is loaded, if you look in Xorg.0.log there you can see the following lines:
```
[50.156] (--) NVIDIA(GPU-0):
[50.170] (--) NVIDIA(GPU-0): Ancor Communications Inc ASUS PB258 (DFP-1): connected
[50.170] (--) NVIDIA(GPU-0): Ancor Communications Inc ASUS PB258 (DFP-1): Internal TMDS
[50.170] (--) NVIDIA(GPU-0): Ancor Communications Inc ASUS PB258 (DFP-1) Name Aliases:
[50.170] (--) NVIDIA(GPU-0): DFP
[50.170] (--) NVIDIA(GPU-0): DFP-1
[50.170] (--) NVIDIA(GPU-0): DPY-3
[50.170] (--) NVIDIA(GPU-0): HDMI-0
[50.170] (--) NVIDIA(GPU-0): DPY-EDID-8d10b4c6-bc31-7a8f-4a55-4e92a2205b6c
[50.171] (--) NVIDIA(GPU-0): HDMI-0
[50.171] (--) NVIDIA(GPU-0): Ancor Communications Inc ASUS PB258 (DFP-1): 225.0 MHz maximum pixel clock
[50.171] (--) NVIDIA(GPU-0):
[50.171] (--) NVIDIA(GPU-0): --- EDID for Ancor Communications Inc ASUS PB258 (HDMI-0) ---
[50.171] (--) NVIDIA(GPU-0): EDID Version : 1.3
[50.171] (--) NVIDIA(GPU-0): Manufacturer : ACI
[50.171] (--) NVIDIA(GPU-0): Monitor Name : Ancor Communications Inc ASUS PB258
[50.171] (--) NVIDIA(GPU-0): Product ID : 0x25a1
[50.171] (--) NVIDIA(GPU-0): 32-bit Serial Number : 0x00002086
[50.171] (--) NVIDIA(GPU-0): Serial Number String : F2LMTJ008326
[50.171] (--) NVIDIA(GPU-0): Manufacture Date : 2015, week 6
[50.171] (--) NVIDIA(GPU-0): DPMS Capabilities : Active Off
[50.171] (--) NVIDIA(GPU-0): Input Type : Digital
[50.171] (--) NVIDIA(GPU-0): Prefer first detailed timing : Yes
[50.171] (--) NVIDIA(GPU-0): Supports GTF : No
[50.171] (--) NVIDIA(GPU-0): Maximum Image Size : 550 mm x 310 mm
[50.171] (--) NVIDIA(GPU-0): Valid HSync Range : 24.0 kHz - 99.0 kHz
[50.171] (--) NVIDIA(GPU-0): Valid VRefresh Range : 23.0 Hz - 76.0 Hz
[50.171] (--) NVIDIA(GPU-0): EDID maximum pixel clock : 300.0 MHz
[50.171] (--) NVIDIA(GPU-0): CEA-861 extension block # : 0
[50.171] (--) NVIDIA(GPU-0):
[50.171] (--) NVIDIA(GPU-0): CEA-861 revision : 3
[50.171] (--) NVIDIA(GPU-0):
[50.171] (--) NVIDIA(GPU-0): IEEE Vendor Registration ID: 00-0c-03
[50.171] (--) NVIDIA(GPU-0): Supports YCbCr 4:4:4 : Yes
[50.171] (--) NVIDIA(GPU-0): Supports YCbCr 4:2:2 : Yes
[50.171] (--) NVIDIA(GPU-0): Supports Basic Audio : Yes
[50.171] (--) NVIDIA(GPU-0): Audio Descriptor : 0
[50.171] (--) NVIDIA(GPU-0): Audio Format : PCM
[50.171] (--) NVIDIA(GPU-0): Maximum Channels : 2
[50.171] (--) NVIDIA(GPU-0): Sample Rates : 32KHz, 44KHz, 48KHz, 96KHz
[50.171] (--) NVIDIA(GPU-0): Sample Sizes : 16-bits, 20-bits, 24-bits
[50.171] (--) NVIDIA(GPU-0): Speaker Allocation Data :
[50.171] (--) NVIDIA(GPU-0): Front Left + Front Right
[50.171] (--) NVIDIA(GPU-0):
```
Interestingly, the EDID of the monitor, writes about **300 MHz** , but another line
> [50.171] (–) NVIDIA(GPU-0): Ancor Communications Inc ASUS PB258 (DFP-1): 225.0 MHz maximum pixel clock
writes about **225.00 MHz**
But if you boot into the nouveau driver, then in Xorg. 0. log there are such lines:
> [59.846] (II) modeset(0): Serial No: F2LMTJ008326
> [59.846] (II) modeset(0): Ranges: V min: 23 V max: 76 Hz, H min: 24 H max: 99 kHz, **PixClock max 305 MHz**
> [59.846] (II) modeset(0): Monitor name: ASUS PB258
I have:
Display: ASUS PB258
Linux kernel: 5.4.57
```
$ inxi -G
Graphics: Device-1: NVIDIA GF114 [GeForce GTX 560] driver: nvidia v: 390.141
Display: server: X.Org 1.20.8 driver: loaded: nvidia resolution: 1920x1080~60Hz
```
Xorg.0.log on nvidia driver with “debug mode on”: [Xorg.0.log.nvidia.gz](https://forums.developer.nvidia.com/uploads/short-url/9oyEv1dNJWUrnK1DX7KPTexk48g.gz) (33.3 KB)
Xorg.0.log on nouveau driver: [Xorg.0.log.nouveau.gz](https://forums.developer.nvidia.com/uploads/short-url/sbfXHJlSJ5p3rU9HKuGgwuIzpK0.gz) (11.4 KB)
Thanks in advance.
---
### Author:  [@generix](https://forums.developer.nvidia.com/u/generix)
#### Post date: [March 5, 2021, 5:10pm UTC](https://forums.developer.nvidia.com/t/incorrect-definition-of-pixel-clock-390-141/170159/2 "2021-03-05T17:10:18Z")
Try setting in xorg.conf
```auto
Option "ModeValidation" "NoMaxPClkCheck"
```