High CPU Usage @idle: System Interrupts. Source?

Guys I need some guidance hunting the cause of high System Interrupts level on a freshly-installed notebook. This is a hp g4-1117dx, with amd llano/hudson, A4-3300m, 4gb, crucial ssd, etc. no external devices used at all.

at idle i have an unacceptably high level of system interrupts, around ~30% cpu utilization. I've checked drivers carefully, but as you know, just because its recent and sourced right is no guarantee of success :cry
I've tried disabling all USB hubs via Device Manager, no change whatsoever.
tried disabling and uninstalling WIFI, NIC, GPU... none of that had any noticable effect. tried uninstalling and reinstalling the IDT audio device. no effect.

I have never used Process Explorer 'til now so I dont' know what I'm doing with it. it shows the general problem but drilling down I can't find the item that is sourcing this flurry - but then I have no idea how to do so properly. I read about xperf but it looks more complicated. I have pretty decent skills so not afraid to give it a go but wanted some advice

I'm attaching one of my shots. this is pretty much the story despite many attempts

thanks

 

Does safe mode give the same issue?

 

i solved it.
it was the amd sata driver that 8/10 load auto when setting up the system.
i was stumped in that, I guess part of the dysfunction of the driver is that features were not availed in Device Manager, one of them being the option to uninstall the driver for that device. finally figured out that I could simply pick from the list embedded, and was surprised when it effected the switchover to the MS driver.

I remembered all this when I looked it up on my thinkpad, which has the same chipset [hudson] - had to switch it over from amd to microsoft awhile back.

cpu usage dropped from constant mid-30's to around 1%
yeah baby