Main Restorations Software Audio/Jukebox/MP3 Everything Else Buy/Sell/Trade
Project Announcements Monitor/Video GroovyMAME Merit/JVL Touchscreen Meet Up Retail Vendors
Driving & Racing Woodworking Software Support Forums Consoles Project Arcade Reviews
Automated Projects Artwork Frontend Support Forums Pinball Forum Discussion Old Boards
Raspberry Pi & Dev Board controls.dat Linux Miscellaneous Arcade Wiki Discussion Old Archives
Lightguns Arcade1Up Try the site in https mode Site News

Unread posts | New Replies | Recent posts | Rules | Chatroom | Wiki | File Repository | RSS | Submit news

  

Author Topic: Groovymame - Groovy Arcade - Linux Xorg issue  (Read 2032 times)

0 Members and 1 Guest are viewing this topic.

Doozer

  • Trade Count: (0)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 498
  • Last login:June 12, 2023, 09:19:49 am
  • Z80 ERROR
Groovymame - Groovy Arcade - Linux Xorg issue
« on: February 11, 2017, 12:30:56 am »
If you are making regular upgrades to your Linux distribution, refrain yourself from upgrading to xorg-server-1.19.x version. The latest X versions does not handle the V-sync redraw properly.

The latest Xorg server working without issue with GM is v1.18.4.

If you still need to use Xorg 1.19x version, you have to enable the ShadowPrimary option in xorg.conf (see example below). The impact on input latency is negligible. Measured latency is 2 to 3 frames.

Quote
Option "ShadowPrimary" "boolean"

    This option enables a so-called "shadow primary" buffer for fast CPU access to pixel data, and separate scanout buffers for each display controller (CRTC). This may improve performance for some 2D workloads, potentially at the expense of other (e.g. 3D, video) workloads. Note in particular that enabling this option currently disables page flipping. The default is off.

Code: [Select]
Section "Device"
    Identifier "Radeon"
    Driver "radeon"
    Option "ShadowPrimary" "on"
EndSection

<@admin, can this thread be flagged sticky?>
« Last Edit: February 11, 2017, 02:51:04 am by Doozer »

Calamity

  • Moderator
  • Trade Count: (0)
  • Full Member
  • *****
  • Offline Offline
  • Posts: 7463
  • Last login:July 19, 2025, 04:03:33 am
  • Quote me with care
Re: Groovymame - Groovy Arcade - Linux Xorg issue
« Reply #1 on: February 11, 2017, 06:58:22 am »
Great news Doozer!

How did you measure input latency? Those 2 to 3 frames are absolute total latency or relative the usual on Linux?
Important note: posts reporting GM issues without a log will be IGNORED.
Steps to create a log:
 - From command line, run: groovymame.exe -v romname >romname.txt
 - Attach resulting romname.txt file to your post, instead of pasting it.

CRT Emudriver, VMMaker & Arcade OSD downloads, documentation and discussion:  Eiusdemmodi

Doozer

  • Trade Count: (0)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 498
  • Last login:June 12, 2023, 09:19:49 am
  • Z80 ERROR
Re: Groovymame - Groovy Arcade - Linux Xorg issue
« Reply #2 on: February 11, 2017, 08:43:44 am »
Latency has been measured with a 1000 Hz hid device with a led wired to the input (a key press lights the led). With a 120 frames/s camera I did several captures with different games. Results are showing at least 1 frame better than in the past (1 year old). No idea from where it is coming from, but it is going the right way.

There is also new rendering mechanisms available to speed up 2D drawing and eliminate tearing within the X server. But I have not seen any test showing the benefits.