[LAU] ACPI, HW and Jack issues?

Hi LAU, Right now, I'm optimizing my system for audio work, and have experienced some problems. First, this is my system: Kubuntu 9.04 with 2.6.28-3-rt (noacpi nosmp (the system freezes w/o nosmp, possible because of the nvidia x-driver)), jack 1.9.2 running on an Athlon64 X2 6400+, 3.2 GHz with 8 GB RAM and a MSI K9N SLI Platinum MB. The Soundcard is a Delta 1010 from M-Audio. All in all, a decent Audio HW I believe. Normally, my DSP load varies from 1 to 2% when the Jack server runs without other Jack enabled apps. ACPI is enabled on the MB and disabled as a kernel parameter; but so far, so good. Lately, I have tried to assign IRQ 9 (occupied by ACPI) to my 1010 card wo. success (can't assign the PCI port to IRQ 9 in BIOS), it's always shared with sata_nv, sata_nv and ohci_hcd:usb2 (from cat /proc/interrupts). What I now tried is to just disable ACPI on the MB (from BIOS) in order to free IRQ9 and it's now the funny things starts: now, the DSP load is from 0.0004% (very rare, but typical down to aprox. 2%) and stays mostly up to around 38%! I have done the usual work in /etc/security/limits.conf, and the indexing work in /etc/modprobe.d/alsa-base.conf in order to lock the 1010 to hw:1. Jack priority is 70, frames 64, sample rate is 44100 and periods 2 (latency 2.9 - earlier, I could reduce to 0.7 ms when needed w/o x-runs). So what's up here? Why can't i separate the 1010 from the system? The 1010 is sharing the IRQ with the HDs, that's nothing I want. Why the insane DSP load when ACPI is off in BIOS? The outputs of "cat /proc/interrupts" and "lspci" are at the end of this posting. Thanks, Jostein ------------------------------------------------ Here is my "cat /proc/interrupts" cat /proc/interrupts CPU0 0: 876748 XT-PIC-XT timer 1: 2 XT-PIC-XT i8042 2: 0 XT-PIC-XT cascade 5: 257354 XT-PIC-XT sata_nv 7: 2 XT-PIC-XT 8: 1 XT-PIC-XT rtc0 9: 0 XT-PIC-XT acpi 10: 760257 XT-PIC-XT sata_nv, sata_nv, ohci_hcd:usb2, ICE1712 11: 56400 XT-PIC-XT ehci_hcd:usb1, HDA Intel, nvidia 12: 4 XT-PIC-XT i8042 14: 8314 XT-PIC-XT pata_amd 15: 0 XT-PIC-XT pata_amd 2297: 85027 PCI-MSI-edge eth0 NMI: 0 Non-maskable interrupts LOC: 0 Local timer interrupts RES: 0 Rescheduling interrupts CAL: 0 Function call interrupts TLB: 0 TLB shootdowns SPU: 0 Spurious interrupts ERR: 2 lspci: 00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2) 00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3) 00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3) 00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1) 00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2) 00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1) 00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2) 00:06.1 Audio device: nVidia Corporation MCP55 High Definition Audio (rev a2) 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:0a.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0d.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0e.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 01:00.0 Multimedia audio controller: VIA Technologies Inc. ICE1712 [Envy24] PCI Multi-Channel I/O Controller (rev 02) 07:00.0 VGA compatible controller: nVidia Corporation GeForce 8400 GS (rev a1)