Thanks for the clarification. The situation you described could well be associated with the gpu lockup. The way to be certain is to look at dmesg after experiencing one of these lags:
[ 630.190999] [drm] capturing error event; look for more information in /debug/dri/0/i915_error_state [ 630.192053] i915: render error detected, EIR: 0x00000010 [ 630.192053] i915: IPEIR: 0x00000000 [ 630.192053] i915: IPEHR: 0x01000000 [ 630.192053] i915: INSTDONE_0: 0xfffffffe [ 630.192053] i915: INSTDONE_1: 0xffffffff [ 630.192053] i915: INSTDONE_2: 0x00000000 [ 630.192053] i915: INSTDONE_3: 0x00000000 [ 630.192053] i915: INSTPS: 0x0001e000 [ 630.192053] i915: ACTHD: 0x052175d0 [ 630.192053] i915: page table error [ 630.192053] i915: PGTBL_ER: 0x00000001 [ 630.192053] [drm:i915_report_and_clear_eir] *ERROR* EIR stuck: 0x00000010, masking That one looks like it happened about 10 minutes after booting. ** Changed in: xserver-xorg-video-intel (Ubuntu) Status: Incomplete => Triaged ** Changed in: xserver-xorg-video-intel (Ubuntu) Importance: Undecided => High ** Summary changed: - [gm45] GPU lockup EIR: 0x00000010 PGTBL_ER: 0x00000001 IPEHR: 0x02000000 + [gm45] GPU lockup EIR: 0x00000010 PGTBL_ER: 0x00000001 IPEHR: 0x02000000 - sluggish behavior with gimp and totem -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xserver-xorg-video-intel in Ubuntu. https://bugs.launchpad.net/bugs/1116732 Title: [gm45] GPU lockup EIR: 0x00000010 PGTBL_ER: 0x00000001 IPEHR: 0x02000000 - sluggish behavior with gimp and totem Status in “xserver-xorg-video-intel” package in Ubuntu: Triaged Bug description: When using programs such as gimp or totem (which uses the GPU more other programs) on my pc you can have delays of the whole machine and your application darkens, and I was asked to force close it. I would also like to point out that on my computer (with GPU Mobile Intel ® GM45 Express Chipset) from the version 11.04 when moving from plymouth to the login window and after the login you have the screen flashes for a few seconds. I must say that at the time of the release of Ubuntu 13.04 is not very powerful(also in the consumption of the battery) I have a HP620 with: CPU: Intel ® Core ™ 2 Duo CPU T6670@2.20GHz × 2 GPU: Mobile Intel ® GM45 Express Chipset O.S: Ubuntu 13.04 Raring Ringtail (development branch) 64bit xserver-xorg-video-intel info: version: 2:2.21.0-0ubuntu1 ProblemType: Crash DistroRelease: Ubuntu 13.04 Package: xserver-xorg-video-intel 2:2.21.0-0ubuntu1 ProcVersionSignature: Ubuntu 3.8.0-4.8-generic 3.8.0-rc6 Uname: Linux 3.8.0-4-generic x86_64 ApportVersion: 2.8-0ubuntu4 Architecture: amd64 Chipset: gm45 Date: Tue Feb 5 22:41:02 2013 DistroCodename: raring DistroVariant: ubuntu DuplicateSignature: [gm45] GPU lockup EIR: 0x00000010 PGTBL_ER: 0x00000001 IPEHR: 0x02000000 Ubuntu 13.04 ExecutablePath: /usr/share/apport/apport-gpu-error-intel.py GpuHangFrequency: Several times a day InstallationDate: Installed on 2013-02-04 (1 days ago) InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130202) InterpreterPath: /usr/bin/python3.3 MachineType: Hewlett-Packard HP 620 MarkForUpload: True ProcCmdline: /usr/bin/python3 /usr/share/apport/apport-gpu-error-intel.py ProcEnviron: ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-4-generic root=UUID=e2a071f7-aff9-44df-b0c7-31b77815e231 ro quiet splash vt.handoff=7 RelatedPackageVersions: xserver-xorg 1:7.7+1ubuntu4 libdrm2 2.4.41-0ubuntu1 xserver-xorg-video-intel 2:2.21.0-0ubuntu1 SourcePackage: xserver-xorg-video-intel Title: [gm45] GPU lockup EIR: 0x00000010 PGTBL_ER: 0x00000001 IPEHR: 0x02000000 UdevDb: Error: [Errno 2] No such file or directory: 'udevadm' UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: dmi.bios.date: 01/07/2011 dmi.bios.vendor: Hewlett-Packard dmi.bios.version: 68PVI Ver. F.09 dmi.board.name: 1526 dmi.board.vendor: Hewlett-Packard dmi.board.version: KBC Version 71.0D dmi.chassis.asset.tag: CNU1092W4N dmi.chassis.type: 10 dmi.chassis.vendor: Hewlett-Packard dmi.modalias: dmi:bvnHewlett-Packard:bvr68PVIVer.F.09:bd01/07/2011:svnHewlett-Packard:pnHP620:pvrF.09:rvnHewlett-Packard:rn1526:rvrKBCVersion71.0D:cvnHewlett-Packard:ct10:cvr: dmi.product.name: HP 620 dmi.product.version: F.09 dmi.sys.vendor: Hewlett-Packard To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1116732/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp