I'm not beginner when it comes to over clocking, I've had a Barton 2500+ running at 2.2Ghz (essentially an AthlonXP 3200+) I currently have my Opteron 165 at 2.8Ghz (making in an FX-62) My last venture was an Intel E4400 running nicely at 2.93 Ghz, making it an "Extreme Edition". Well, I had some money and the Q6600 has been teasing me for weeks. I decided to jump and get one, because a)my Nvidia motherboard wouldn't support the upcoming Penryn Core cpus, and B)cuz I heard that if you get the G0 Stepping its an easy overclocker, and well I found quite the opposite. Where my E4400 ran at 2.93Ghz with a very limited Voltage bump, the Q6600(which is a G0 stepping BTW) has turned into a nightmare at 3Ghz. I had it running 4 instances of Prime95 for 8 hours and no crash, stable as heck. But when I fire up Crysis I had polygons flying everywhere. And when I play Unreal Tournament 3 it sometimes crashes. And at boot it occasionally crashes to a black screen with a bunch of white text with nonsense, or starts going into windows and crashes and restarts. This makes absolutely no sense to me. Prime95(and Orthos and SP2004) haven't steered me wrong yet, why would they now? Just for giggles I ran A 4 hour loop of 3DMark06(the cpu test in that is CrAzY) and no crash, stable as heck. The Q6600 doesn't even get that hot. I got an Arctic Cooling Freezer 7 and temps at load rarely hit 57c. Right now I have it at 1.45 volts at 3.0Ghz and it seems stable enough. I just don't like it at that high of voltage. Also another strange anomaly are white dots. I see white dots on the Icon for selecting suit powers in Crysis, I don't remember them their with my E4400, and when I swapped out my 8800GTS with my 7600GS they were still their. Also, I lowered the settings on the CPU to default and the white dots stayed their. Uninstalled and reinstalled the drivers 4 times and white dots stay. Reinstalled the game and, guess what? The white dots are still there!!!!!

Any help would be greatly appriciated!

From the details you give, perhaps it's not the cpu at all? Perhaps the memory/video card. Whats the situation on those? are you OC them to?

The Memory is acctually underclocked (It's ADATA DDR2 800) and the videocard is stock. Here are my System specs

Intel Core2 Q6600
MSI P6N-FI
AData DDR2 800
Arctic Cooling Freezer 7 Pro+
XFX Geforce 8800GTS XXX
2x ASUS DVD+/-RW
2x Western Digital 500 GB HDD
Seasonic 600 Watt SLI certified PSU
Coolermaster Centurion Case

Try running memtest for an hour or two... have you run prime in blend to check over all stability? that will beat up the ram as well. Also on a side note. If you find that all parts are stable and you need almost 1.5 volts to reach 3.0 on that processor, I would say that you got a lemmon and you should rma it. My b3 q6600 is at 3.0 ghz on stock volts of 1.2625 set in bios.

Yeah, I'm RMAing it, my E4400 runs at 2.93 no prob, but then again, I have the FSB at 1172 with the 10 times multiplyer. When I try the E4400 at 1333 fsb it refuses to boot. I don't know if this motherboard sucks or I drew unlucky lottery with CPUs from intel.

The white dots are normally artifacts from the GPU.

I would almost say it's the motherboard.

Yea that's a high voltage for 3.0 GHz, but it's stable on Prime95. That's not exactly a great board for trying to overclock a quad... I don't know man, I have a feeling the issues will still be there when you drop a new Q6600 in, but hell RMA it and give it a shot, atleast you might win a better lottery.

Just for fun, what's the VID in coretemp?

The white dots...Yeah I thought it was the GPU too...in fact I wish it was, would give me good reason to get an 8800GT or Radeon 3870. But it isn't, I popped my 7600GS and 7900GT and got the same artifacts. Got my dual core in it right now, packed up the quad and getting ready for RMA. If it is the board, any recommendations on a good OCing motherboard. Kinda gonna stay away from nVidia as this i650 board has left a bad taste in my mouth. Thinking of getting a P35 based one, any recommendations?

Oh, what is VID in Coretemp mean? In prime it never went over 61c even with 1.4 volts.

VID is the "stock" voltage reference given to the board to run it at stock voltage.

Edit: Also if you want to move to a P35 I would recommend (for a quad core) the P5K series from Asus. Specifically the E model and up (Deluxe, Premium). Great for OCing quads and have 8 phase Vregs.

Ok, thought of somthing, Does upping the VTT help increase stability at all? I've got it 6% higher and got my E4400 into Windows. My previous top speed was 2.93 Ghz. Could increasing VTT actually help?

Ok,I popped the Q6600 back in and I set the VTT up to 8%, set the FSB to 1333 and the multiplyer to 9. The Voltage to the CPU is 1.28 and I played a good hour of UT3. I used UT3 to test initial stability because whenever I played it before it crashed and burned no matter how much voltage I used on the CPU. Right now I have my Q6600 at 3.0Ghz, lets hope she's stable, gonna run Prime95 blended and give results in the morning.

I don't know the quirks of that board, it might need the VTT. Mine doesn't need stuff like that til 425+ Bus.

Ok, I just did this. I lowered the voltage on the processer down to 1.28v and got the FSB running at 1333 with a multiplyer of 9. What I did different this time was upped the FSB VTT up by 8%. I always left it at zero because, coming from years of AMD64 overclocking and not having to deal with a front side bus, I didn't know what it was. Apparently upping this assists in FSB stability. After doing that I booted up Unreal Tournament 3 and played for about an hour, that game always gave me problems before, and it was solid as a rock. Then fired up Crysis, which was a big diff going from fast as hell UT3 to slow as hell Crysis, and it didn't crash upon exit like it did sooooo many times before. So with the VTT upped I started prime(this time in blend mode) at around 1am last night. Now I wake up at about 8am and she's still running. Only think Is I already put an RMA in for it, and I don't wanna send it back cuz It's running fine for me, I don't need 3.6ghz (would be nice, but I suspect the board SUCKS). I'm happy humming along at 3.0Ghz. Thanks to everyone who read this thread and tried to help.

Ok, just updating this incase anyone out there gets simular issues, its still running strong, but I do get visual imperfections in UT3 and Crysis. Did the same thing with the Q6600 at stock. Also had same issues with the E4400 Stock and at 2.93 ghz. So I think the failed OC's before screwed up those two games. Also, for those out there with 2mb or 4mb Core2 Duo's and are thinking up getting a Q6600 at the same speed, I'll tell you, I noticed very little diff. between the E4400 (2.93ghz) and the Q6600(3.00 Ghz) Save your money for a better video card. Me, I use premier and like doing a whole bunch of things at the same time the Q works out pretty good.