I'm sure when you enabled the "Load Legacy Option Rom" the bios initialize some of the hardware differently then when that option is disabled.
I'm sure that I'm booting with the efi kernel Command line: BOOT_IMAGE=/boot/vmlinuz-3.11.0-12-generic.efi.signed ** Attachment added: "dmesg" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1234546/+attachment/3884363/+files/dmesg -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1234546 Title: Plymouth screen refresh is bad when Live USB is started in UEFI mode Status in “linux” package in Ubuntu: Confirmed Bug description: Test computer : Dell XPS 13 L322x with Intel Graphics HD4000. I burnt a Live Ubuntu Gnome 13.10 USB, first with the Beta 1, and with the 2013-09-30 daily image. This USB key has been created with Rufus under Windows and is compliant for both UEFI and Bios mode. If I boot on the key in Bios mode, no problem, I see the first screen in text mode (Install, test only...). After having chosen "test only", I see the Gnome footprint and everything runs. If I boot the key in UEFI mode (SecureBoot is disabled), I see the first screen. After having chosen "test only", plymouth starts but the screen refresh frequency is bad, so I have many footprints on the screen, etc. Everything seems to run fine also, except this screen refresh frequency. ProblemType: Bug DistroRelease: Ubuntu 13.10 Package: plymouth 0.8.8-0ubuntu8 ProcVersionSignature: Ubuntu 3.11.0-9.16-generic 3.11.2 Uname: Linux 3.11.0-9-generic x86_64 ApportVersion: 2.12.5-0ubuntu1 Architecture: amd64 Date: Thu Oct 3 09:00:43 2013 DefaultPlymouth: /lib/plymouth/themes/ubuntu-gnome-logo/ubuntu-gnome-logo.plymouth InstallationDate: Installed on 2013-09-22 (10 days ago) InstallationMedia: Ubuntu-GNOME 13.10 "Saucy Salamander" - Alpha amd64 (20130903) MachineType: Dell Inc. Dell System XPS L322X MarkForUpload: True ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-9-generic.efi.signed root=UUID=529ee009-cfab-4b00-832d-5390f382f988 ro quiet splash vt.handoff=7 ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-9-generic.efi.signed root=UUID=529ee009-cfab-4b00-832d-5390f382f988 ro quiet splash vt.handoff=7 SourcePackage: plymouth TextPlymouth: /lib/plymouth/themes/ubuntu-gnome-text/ubuntu-gnome-text.plymouth UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 05/15/2013 dmi.bios.vendor: Dell Inc. dmi.bios.version: A09 dmi.board.name: 0PJHXN dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: 0.1 dmi.modalias: dmi:bvnDellInc.:bvrA09:bd05/15/2013:svnDellInc.:pnDellSystemXPSL322X:pvr:rvnDellInc.:rn0PJHXN:rvrA00:cvnDellInc.:ct8:cvr0.1: dmi.product.name: Dell System XPS L322X dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1234546/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp