huge dpc spikes

[Ford442]

i just built a new pc and i'm ironing out the kinks - my last major problem is that i get a huge spike in dpc latency incurred by SCSIPORT.SYS evry hour or two - i use my pc for music production so i really need to fix this - i get a one or two second spike where my dpc goes through the roof to 250000us or so - audio crackles - all apps pause - not good for audio work...

here is my setup:
Intel Q9650
Gigabyte GA-EP45-UD3P
EVGA GTX 260 SSC
Corsair Dominator DDR 2 - 4gb
Firewire Audiophile
TC Electronics Powercore Element PCI
Logitech MX700 wireless mouse
Windows XP Home SP3

nothing is overclocked..

all i can tell is that it involves SCSIPORT.SYS - i used RATT to monitor dpc..

i have tried disabling the powercore in device manager - but i have not yet physically removed it to test because it is a huge full-size 12" card and it is underneath cables in my case - it will be hard to get out and even harder to get back in.. but, i will try that soon...

i have tried removing most every other device...

thank you very much for any input!

 

[GaryJohnson]

What kind of hard drive setup are you running?

If you're not running RAID, try setting these in the BIOS -> Integrated Peripherals:
SATA RAID/AHCI Mode -> Disabled
SATA Port0-3 Native Mode -> Disabled
And connect your SATA drives ports 0,1,2, and/or 3.

 

[Ford442]

no - i'm not diong RAID, but i'm a little wary of changing AHCI back to IDE mode.. my drives are already on 0,1,2...

 

[Ford442]

can you assure me that i can change from AHCI to IDE and back without reinstalling windows?

 

[GaryJohnson]

IDE to AHCI is where you usually get boot problems, but going from AHCI back to IDE I don't think will cause you any issues. If it won't boot you can change it back.

Either way, this might be the way to solve the problem. In which case if it doesn't work, you may need the reinstall, or at least a repair install.

 

[Ford442]

i've been told that i would probably have to do a repair just to go back to IDE.. i really don't want to do that.. dang it.. i will keep it in mind for now..

 

[Ford442]

i believe i have fixed the problem.. well - a workaround anyway -

the problematic driver is for the secondary SATA controller - thankfully not the OS one, so i updated the driver with no change - now i've moved all files off both IDE drives and disabled JMicron SATA2 in my BIOS - no spikes overnight..

thanks for the input!