Trust your ears Nick....Oh boy... Right here we go !
I have been looking at ways to set affinity of drivers after something the Peter said in a post. The basic theory is that if you can arrange the systems IRQ handeling work load across processors then you can give XXHighend and your sound device driver a BIG slice of uninterrupted system resources to be super responsive and make great music.
For about a year I have been playing with 2 CPUs out of 4 because as I add in the extra CPUs sound deteriorates badly. I’m listening now with 4CPUs to sound I find the sound hard to distinguish from a record player. My wife has the most sensertive ears of anyone I know (she can still easily hear bats), the slightest digital distortion makes her literally run from the room. She has just given a big thumbs up to the sound which is a first in years..HOW ?
All of the none music related IRQs on my system are being serviced on CPU 0 alone. CPU 2 is now used for HighEnd Engine 3 and my USB (I use a USB SPDIF interface), RamDisk and Hiface Drivers IRQ requests are running on CPUs 1,2 and 3 (unfortunatly thats all the CPUs I have right now
). 3 / 4 of the CPUs are now running only Music related IRQ requests.
The recipe for this setup is a program called IntFiltr which is a .sys driver that allows you to assign IRQs to CPUs. It is not intended for Vista but seems to work fine on my system. You can get the software at this location and installation instruction are also there. Just remember to run the configuretor as Administrator.
http://support.microsoft.com/kb/252867How to assign IRQs for XXHighEnd Music replay (tested on Vista)
1) Install the package
2) Enable all the CPUs you have on your system using normal config options.
3) Reboot
4) Set you XXHighEnd to run CPU appointment scheme 2 (Engine3.exe then runs on CPU 1)
5) Run the IntFiltr configuration application
6) In IntFilter select one by one each devices in the list [with the exception any devices related to CPU, Disk, PCI bus and your music devices (music devices include USB and Firewire devices if this are used to play)] and click “Add Filter” for the selected device. Then using the “Set Mask” button set the affinity for these devices to CPU 0.
7) Leave your Disk, CPU and PCI devices and anything else you think should not be touched as they are (don’t create Filters for these).
Now find you connection devices (USB / Firewire) and your sound card and “Add Filter” Filter for each of these. For these use “Set Mask” to use CPUs 1,2,3,,,[Max CPU no].
Notes.
If any of sound replay devices (USB, Firewire, sound card) share IRQs make sure you apply the CPUs 1,2,3,,,[Max CPU no] to the other devices that share the IRQs
That’s it reboot make a cup of tea (well i am from the UK) and sit back and listen.
Nick.