forge wrote:thanks but it's a laptop
The bad things about laptops is their lack of customisation. Try finding out the IRQ of your PCMCIA/PCIe-card slot. Maybe it doesn't share IRQs and thus runs better than the onboard solution. The fact that they share IRQ 16 shows that Windows is doing it wrong, try deactivating some unused hardware. Also have a look at how Vista sets up these IRQs, maybe there is the difference between why your FW runs properly under Vista but not under XP.
as far as I've been able to tell the only way I could manually change them is to go into standard PC mode or something - I have a memory of ruining my day once doing that years ago - caused all kinds of problems
I just googled MPS multiprocessor...I found this interesting thread
That's what I meant in my previous post. Generally ACPI should run properly on all modern systems and is to be prefered then. Unfortunately some BIOS/mainboard manufacturers
may still do bad implementations or some plugin cards may not work. I can work with or without ACPI on my PC, but don't see no benefit from switching it off on my system.
others seem to have gone to MPS multiproc for this reason (well, dropouts at least) and get better latency
You can always try.
I have speedswitchXP installed - will that control it for me under MPS...?
Generally I see little benefit by using utilities like SpeedswitchXP beside the ability to permanently clock the CPU to a set minimum (or anything in between). I have used Rightmark's CPU Clock Util which should be even more sophisticated than SpeedswitchXP, but in "Dynamic" mode it generally runs worth than Windows' build-in clock-switching via Energy-Managment. The reason for the worse performance is that these applications run at "Realtime" priority in User space while Windows' own energy-managment and your CPU's driver run on a lower system-level and thus work more integrated and perfoming when doing dynamic switching.
Anyway, you better turn off
any dynamic CPU clock if you need maximum Audio performance. Else you may notice drop-outs in Live even when CPU load is low. My advice is to turn on Windows XP's energy-managment tray-icon and switch to "Desktop" when working on audio (if you're using a power-plug instead of batteries), this will turn off dynamic clocking and clock the CPU to max. Any other energy-managment profile will turn on dynamic clocking (aka Speedstep, PowerNow, Cool&Quiet).
For example, on most mainboards the lowest position PCI slot shares IRQ with the graphic-card. Here is an example of my own mainboard:
