I recenty started to migrate from Lucid (10.04) to Precise (12.04). Unfortunately, I have noticed that the video rendering performance has decreased with Precise. Videos with a resolution of about 720x576 that are played smoothly on Lucid are either flickering or shortly hanging in-between while played on Precise (the standard video player tends more to flickering, in vlc I get hangs).
I should mention that I have a quite old graphics card, it is identified by the X server as
Chipset: "ATI Radeon VE/7000 QY (AGP/PCI)" (ChipID = 0x5159)
After experimenting around quite a while I found out that I get back the old performance if I boot with "nomodeset", so I guess there's a bug in kernel modesetting.
BTW, the output of "uname -a" is
Linux faramir 3.2.0-32-generic-pae #51-Ubuntu SMP Wed Sep 26 21:54:23 UTC 2012 i686 athlon i386 GNU/Linux
---
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 2.0.1-0ubuntu14
Architecture: i386
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: piet 2050 F.... pulseaudio
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Card0.Amixer.info:
Card hw:0 'V8237'/'VIA 8237 with ALC850 at 0xe800, irq 22'
Mixer name : 'Realtek ALC850 rev 0'
Components : 'AC97a:414c4790'
Controls : 49
Simple ctrls : 30
Card2.Amixer.info:
Card hw:2 'UART'/'MPU-401 UART at 0x300, irq 10'
Mixer name : ''
Components : ''
Controls : 0
Simple ctrls : 0
Card2.Amixer.values:
DistroRelease: Ubuntu 12.04
HibernationDevice: RESUME=UUID=f8b00408-9845-97bf-7c8b-0408a45ef8b7
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta i386 (20120328)
IwConfig:
lo no wireless extensions.
eth1 no wireless extensions.
eth0 no wireless extensions.
MachineType: System manufacturer System Product Name
Package: linux (not installed)
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
LANG=de_DE.UTF-8
SHELL=/bin/bash
ProcFB:
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-32-generic-pae root=UUID=b90b85f9-e205-4221-97b3-a64bbbd735a1 ro nomodeset
ProcVersionSignature: Ubuntu 3.2.0-32.51-generic-pae 3.2.30
RelatedPackageVersions:
linux-restricted-modules-3.2.0-32-generic-pae N/A
linux-backports-modules-3.2.0-32-generic-pae N/A
linux-firmware 1.79.1
RfKill:
Tags: precise
Uname: Linux 3.2.0-32-generic-pae i686
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
WifiSyslog:
dmi.bios.date: 11/03/2005
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0219
dmi.board.name: A8V
dmi.board.vendor: ASUSTeK Computer Inc.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0219:bd11/03/2005:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerInc.:rnA8V:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
moved to linux kernel package, which contains the modesetting