It is great to see others have experienced this problem, and are trying to find a solution! The jitter/granular distortion that Tim (the other Tim!), Ico, and Derek describe seems to match exactly what I am experiencing, however I think my hardware is completely different. I wanted to post information about my current state for the record before I start experimenting with acpi and all the other suggestions. I am only on the CCRMA and LAU list, so feel free to forward this info to other lists, such as alsa or whatever. Thanks! -Tim ---------------------- I am running stock model ACER TavelMate254, which actually seems like a decent quality machine: TM254ELCi, LX.T3206.187 Processor Intel® Pentium® 4 processor 2.80GHz Memory 512MB Hard Drive 40GB Optical Drive CD-RW/DVD combo TFT Display 15.0" XGA Graphics Intel® Extreme Graphics 2 ---------------------- I am running the latest PlanetCCRMA kernel and their alsa flavors. ---------------------- here is my lspci output: 00:00.0 Host bridge: Intel Corp. 82852/855GM Host Bridge (rev 02) Flags: bus master, fast devsel, latency 0 Memory at <unassigned> (32-bit, prefetchable) Capabilities: <available only to root> 00:00.1 System peripheral: Intel Corp. 855GM/GME GMCH Memory I/O Control Registers (rev 02) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, fast devsel, latency 0 00:00.3 System peripheral: Intel Corp. 855GM/GME GMCH Configuration Process Registers (rev 02) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, fast devsel, latency 0 00:02.0 VGA compatible controller: Intel Corp. 82852/855GM Integrated Graphics Device (rev 02) (prog-if 00 [VGA]) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, fast devsel, latency 0, IRQ 5 Memory at e8000000 (32-bit, prefetchable) [size=128M] Memory at e0000000 (32-bit, non-prefetchable) [size=512K] I/O ports at 1800 [size=8] Capabilities: <available only to root> 00:02.1 Display controller: Intel Corp. 82852/855GM Integrated Graphics Device (rev 02) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: fast devsel Memory at f0000000 (32-bit, prefetchable) [size=128M] Memory at e0080000 (32-bit, non-prefetchable) [size=512K] Capabilities: <available only to root> 00:1d.0 USB Controller: Intel Corp. 82801DB (ICH4) USB UHCI #1 (rev 03) (prog-if 00 [UHCI]) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, medium devsel, latency 0, IRQ 5 I/O ports at 1820 [size=32] 00:1d.1 USB Controller: Intel Corp. 82801DB (ICH4) USB UHCI #2 (rev 03) (prog-if 00 [UHCI]) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, medium devsel, latency 0, IRQ 11 I/O ports at 1840 [size=32] 00:1d.2 USB Controller: Intel Corp. 82801DB (ICH4) USB UHCI #3 (rev 03) (prog-if 00 [UHCI]) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, medium devsel, latency 0, IRQ 4 I/O ports at 1860 [size=32] 00:1d.7 USB Controller: Intel Corp. 82801DB (ICH4) USB2 EHCI Controller (rev 03) (prog-if 20 [EHCI]) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, medium devsel, latency 0, IRQ 10 Memory at e0100000 (32-bit, non-prefetchable) [size=1K] Capabilities: <available only to root> 00:1e.0 PCI bridge: Intel Corp. 82801BAM/CAM PCI Bridge (rev 83) (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0 Bus: primary=00, secondary=02, subordinate=02, sec-latency=64 I/O behind bridge: 00003000-00003fff Memory behind bridge: e0200000-e02fffff Prefetchable memory behind bridge: e0500000-e05fffff 00:1f.0 ISA bridge: Intel Corp. 82801DBM LPC Interface Controller (rev 03) Flags: bus master, medium devsel, latency 0 00:1f.1 IDE interface: Intel Corp. 82801DBM (ICH4) Ultra ATA Storage Controller (rev 03) (prog-if 8a [Master SecP PriP]) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, medium devsel, latency 0, IRQ 4 I/O ports at <unassigned> I/O ports at <unassigned> I/O ports at <unassigned> I/O ports at <unassigned> I/O ports at 1810 [size=16] Memory at 20000000 (32-bit, non-prefetchable) [size=1K] 00:1f.3 SMBus: Intel Corp. 82801DB/DBM (ICH4) SMBus Controller (rev 03) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: medium devsel, IRQ 10 I/O ports at 1880 [size=32] 00:1f.5 Multimedia audio controller: Intel Corp. 82801DB (ICH4) AC'97 Audio Controller (rev 03) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, medium devsel, latency 0, IRQ 10 I/O ports at 1c00 [size=256] I/O ports at 18c0 [size=64] Memory at e0100c00 (32-bit, non-prefetchable) [size=512] Memory at e0100800 (32-bit, non-prefetchable) [size=256] Capabilities: <available only to root> 00:1f.6 Modem: Intel Corp. 82801DB (ICH4) AC'97 Modem Controller (rev 03) (prog-if 00 [Generic]) Subsystem: Acer Incorporated [ALI]: Unknown device 0038 Flags: bus master, medium devsel, latency 0, IRQ 10 I/O ports at 2400 [size=256] I/O ports at 2000 [size=128] Capabilities: <available only to root> 02:04.0 CardBus bridge: Texas Instruments PCI1250 PC card Cardbus Controller (rev 01) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, medium devsel, latency 168, IRQ 10 Memory at 20001000 (32-bit, non-prefetchable) [size=4K] Bus: primary=02, secondary=03, subordinate=03, sec-latency=176 Memory window 0: 20400000-207ff000 (prefetchable) Memory window 1: 20800000-20bff000 (prefetchable) I/O window 0: 00004000-000040ff I/O window 1: 00004400-000044ff 16-bit legacy interface ports at 0001 02:04.1 CardBus bridge: Texas Instruments PCI1250 PC card Cardbus Controller (rev 01) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, medium devsel, latency 168, IRQ 10 Memory at 20002000 (32-bit, non-prefetchable) [size=4K] Bus: primary=02, secondary=04, subordinate=04, sec-latency=176 Memory window 0: 20c00000-20fff000 (prefetchable) Memory window 1: 21000000-213ff000 (prefetchable) I/O window 0: 00004800-000048ff I/O window 1: 00004c00-00004cff 16-bit legacy interface ports at 0001 02:05.0 Network controller: Harris Semiconductor: Unknown device 3872 (rev 01) Subsystem: AMBIT Microsystem Corp.: Unknown device 0200 Flags: bus master, medium devsel, latency 64, IRQ 11 Memory at e0500000 (32-bit, prefetchable) [size=4K] Capabilities: <available only to root> 02:0a.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10) Subsystem: Acer Incorporated [ALI]: Unknown device 0039 Flags: bus master, medium devsel, latency 64, IRQ 11 I/O ports at 3000 [size=256] Memory at e0200000 (32-bit, non-prefetchable) [size=256] Expansion ROM at <unassigned> [disabled] [size=64K] Capabilities: <available only to root> 03:00.0 Multimedia audio controller: Xilinx Corporation RME Hammerfall DSP (rev 0b) Flags: bus master, stepping, medium devsel, latency 64, IRQ 10 Memory at 20800000 (32-bit, non-prefetchable) [size=64K] ---------------------- proc / interrupts. CPU0 0: 747357 XT-PIC timer 1: 699 XT-PIC keyboard 2: 0 XT-PIC cascade 4: 0 XT-PIC usb-uhci 5: 0 XT-PIC usb-uhci 8: 1 XT-PIC rtc 9: 9 XT-PIC acpi 10: 0 XT-PIC ehci_hcd, Texas Instruments PCI1250 PC card Cardbus Controller, Texas Instruments PCI1250 PC card Cardbus Controller (#2), hdsp 11: 106 XT-PIC usb-uhci, eth0 12: 9397 XT-PIC PS/2 Mouse 14: 21038 XT-PIC ide0 15: 11051 XT-PIC ide1 NMI: 0 ERR: 0