AMD Phenom II x6 1100T @ 6x3,7gHz (i will OC to 4.2gHz)
Asus M3A32 MVP Deluxe motherboard (will change soon)
RAM: 8gb DDR2/800 (will change to DDR3)
HDD: 500gb + 1000gb
graphics: nVidia GT440 + ATI Radeon HD 4350
four LCDs
Primary interface: Edirol M16-DX
Secondary Interface: Edirol UA-1000 - I wil buy another one if someone wants to sell!!!
 
SYSTEM: Windows 7 Ultimate 64bit

plans: better "silent" cooling, changing motherboard and RAM, adding 3rd HDD.

No system related problems with X1 with my:

Dell Desktop PC W7HomePrem/64
Core i5 760 (8MB Cache, 2.8GHz)
8GB DDR3
1 TB SATA
1 TB (ext)
nVidia GeForce GTS240 1024MB GDDR3
EMU1616 PCI (& Realtek PC Audio)
Event ASP6 Active Monitors
Sonar Producer X1c

Note - Running 8.5.3 so relevance is reduced.
 
The PC in my signature is an "off the shelf" model from UK consumer computer company Mesh with the onboard sound disabled and a ESI Juli@ card fitted, along with extra disk drives.
 
There are lots of non-music applications installed including Microsoft Office, Adobe Light Room, Canon photo Software, Bullguard Anti Virus and its connected to the internet.
 
It has no problems running projects with three or four instances of GR4 essentials a couple instances of Kontakt and a few other VSTi and VSTs. 

What I have is listed below. 

Bub,

My specs are:
MSI P67A-GD65 (B3) motherboard
Intel i7 2600K CPU
8gig RAM CORSAIR DOMINATOR
Lynx AES16 PCI Audio Card
GeForce 8500 GT video card
UAD-1 PCI card
2 UAD-2 PCIe cards
Intel 510 120gig SATAIII SSD
Win7 Professional 64-bit

I tried loading two audio tracks and applied GR 4 to both and I'm not experiencing the same issue you stated in the other thread.

Your current i5 PC system certainly seems like it could plenty of tracks/instruments/plugs. 

I'm not sure if you stated if this is only a GR4 issue or if other VSTs have caused similar CPU spikes.  At least that might help to pinpoint better where to look to fix the problem.  If it is only GR4 (all of a sudden), you might be able to talk with NI and see if they can suggest possible remedies.  If other VSTs have the same issue, you can start to look at OS updates or Sonar support for assistance.

Best of luck,
Tom

Has it been one year? Wow how time flies. 

I built a new DAW last August running the i5-750 chip with 4G ram and XP as the OS. I have 2 internal drives, one for OS & applications, the other is library and storage.

I just installed X1 and so far everything is running smooth. 

As my sig:
Asus P5QL-E P43 motherboard
Q9550 C2Quad processor
Noctua CPU cooler
8Gb DDR2
Palit nVidia GT9800 1GB video card

RME HDSP9632 audio card [for X1]
RRK Rokit RP6 G2 active studio monitors

m-Audio Audiophile 2496 audio card [for everything else and monitoring mixes through domestic HiFi rather than studio monitors]
Cambridge Audio Azur340 domestic hifi amp
KEF Cresta2 domestic hifi speakers

Several HDD varying in size from 80GB to 2TB

W7 professional x64
X1 x64

i7 920 (ORIGINAL FIRST GEN, not the ones with a gimped cache. I bought it the first two months of their release) 6gb Gskill DDR3 TC Ram 3x 1TB Deskstar SATA drives Gigabyte UD5 DX motherboard ATI 4850 Supercooled MOTU 8pre Guitar Rig 4 Pro Line6 POD XT Windows 7 home prem. 64bit

Gaze below.

i7 920 (ORIGINAL FIRST GEN, not the ones with a gimped cache.

Oh you don't mean the i7 2600 that already completely smokes a 920 and came in for a third of the price that yours did then?

I can understand your stance.