Comment 85 for bug 254668

"acpi=noirq" does not speed up the boot, but on the other hand seems to solve the shutdown hang at "alsa". I was researching my md5-raid performance and stumbled upon some information that suggested checking the IRQ assignments.
Voilà, the boot hang could be related to IRQ problems (while plug&play yes/or no in the bios does not matter).
Another indicator is that on Hardy, the board would never accept usb mouse and/or keyboard (for example, also very problematic with gparted-live-disks), and with intrepid now I can't even access my usb-stick. PS/2 mouse lights fine, USB mouse never does.
And yet another indicator for severe, maybe related bugs in the kernel: I always get the message (at .0 bootsecs) that I do not have MMIO (memory mapped I/O) enabled. MMIO is a technique that alows external hardware to be "mapped" into RAM and be accessible as such,ancient as from old days of RS232 etc. what do I care if I have 64M more or less with 4-6 gig?) Legacy Parallel and serial is disabled, however, legacy "HID" for USB mouse/keyboard is on.

On Hardy, USB mouse and keyboard where OK to enter the bios but after "Kernel starting up" never worked.

Unfortunatly, this Asus M2NPB-Board (NVIDIA Business Platform haha) has no option similar to the old-familar "DRAM Type for OS >64M / OS/2 select" or whatever that used to be to set the MMIO region. I have the hang shortly after mdadm starts the raid5 (which is 1xide hitachi deskstar 400gib, 1xsata wdc 500gib, 1xsata samsung 500gib... kind of "rag collection" "lumpensammlung") and later around the hal start. Both feel like related to irq/usb issues.

What is absolutely bad: the 500gib WDC Raid edition drive used to make 50-60 MB/s single on read&copy to raid0 and 35-45 MB/s on read&copy from raid0. The raid 0 is a 3xseagate barracuda 250gib raid0 notebook-like 3.5 half height drives on xf.

Processor/Ram: irrelevant. Even a 3800+ instead of 4400+ and DDR667 instead of DDR800 Ram (not that it would matter, cpu was never clocing up from 800 Mhz anyway on operations from/to raid an single disk). Now on intrepid I get 15-20 MB/s on this raid5 with almost always >= 2 GHz processor stepping up)
...

I go for interrupt problems.
The interrupt look like big unsolved conflicts to me.