I have been running my Core i7 920 at 4.0Ghz stable for the last 3 years on a Gigabyte GA-EX58-UD5.  I ran Prime95 on it for a week before I made it my official overclock.  I did get it to 4.2Ghz, but was nervous about the temps being over 80 degrees C at full load.  Three weeks ago, I thought about upgrading the X58 platform for SATA III and USB 3.0.  Two weeks ago I got the eVGA X58 FTW3 and cannot achieve even a minor overclock (2.8Ghz) stable over 10 minutes of Prime95.  I thought maybe my Corsair H50 was bad so I purchased an Antec Kuhler 620 and still not able to OC.  I read several forums and guides.   I'm a computer technician by trade and usually have no problems with overclocks.  I wanted to test stock stability and Prime95 ran for a week (just got back from vacation yesterday) and it was stable at stock CPU settings and RAM at 1066.  RAM is 1600 rated but system is not stable with XMP on profile 1 or 2.  I called eVGA and they said that my memory needs to be running at 1066 since I have a 1066 CPU.  I put everything back into my old setup and everything is stable.  I spent the previous week for hours trying to get stable overclocks.  I wonder if my motherboard is flaky?  Should I have just jumped to socket 2011?  Was this a waste of an upgrade?  I emailed eVGA and they will not help with overclocks (understandably).  Any other ideas?
 
 

Can you tell us your settings that you changed to try and get an overclock?
Copy and paste this template here and adjust what you changed. You will not have some of the features in this template so go ahead and just delete them.
It is possible you just got a bunk mobo. That is just the luck of the draw and not the first time I have seen it.

Not sure what settings you want me to give.  I've started with this guide: http://www.evga.com/forumsarchive/tm.asp?m=716108&mpage=1&key and then used this one: http://www.overclock.net/t/538439/guide-to-overclocking-the-core-i7-920-or-930-to-4-0ghz.  I worked on those step by step and never made it over the 2.6Ghz stable.  Even the Dummy OC fails!  I can give you the settings from my other motherboard as to what I had for reference as to what I'm shooting for at a minimum.  If you have a good starting point that I'm missing, please do let me know.  Also, is there any concern with having 1.5v memory versus all of the other memory in OC guides using 1.65v?  I emailed Corsair and they said they would recommend not going over 1.60v.
 

Frequency Control 
CPU Clock Ratio ( 20x ) 
CPU Host Frequency (Mhz) ( 200 ) 
MCH Strap ( n/a ) 
CPU Uncore Frequency (Mhz) ( 3400Mhz { 17X } ) 
CPU Clock Skew ( n/a ) 
Spread Spectrum ( Disabled ) 
PCIE Frequency (Mhz) ( Auto ) 
QPI Clock Ratio ( 7.2Ghz {x36} )

Memory Feature         
Memory Speed ( Disabled ) 
Memory Control Setting ( Enabled ) 
Memory Frequency ( 1600Mhz / SPD 8.0 ) 
Channel Interleave Setting ( Auto (6) ) 
Rank Interleave Setting ( Auto (4) ) 
Memory Low Gap ( n/a ) 
tCL Setting ( 9 ) 
tRCD Setting ( 9 ) 
tRP Setting ( 9 ) 
tRAS Setting ( 24 ) 
tRFC Setting ( Auto ) 
Command Rate ( 2T ) 


Voltage Control 
Load Line Calibration ( Enabled ) 
CPU VCore ( 1.375 ) 
QPI/VTT Voltage ( 1.515 ) 
CPU PLL VCore ( Auto 1.8 ) 
IOH PLL VCore ( Auto 1.1 )  
DIMM Voltage ( Auto 1.5 ) 
DIMM DQ Vref ( Auto .75 ) 
QPI PLL VCore ( Auto 1.1 ) 
IOH VCore ( Auto 1.1 ) 
IOH/ICH I/O Voltage ( Auto 1.5 ) 
ICH VCore ( Auto 1.1 ) 

CPU Feature 
Intel SpeedStep ( Disabled ) 
Turbo Mode Function ( Disabled ) 
CxE Function ( Disabled ) 
Execute Disable Bit ( Disabled ) 
Virtualization Technology ( Enabled ) **I use VMs**
Intel HT Technology ( Enabled ) 
Active Processor Cores ( All ) 

Interesting try tonight.  I always turned off the Turbo mode.  I left it on and tried 191 x 20 (21x in OS) and it failed at 1.28v CPU, and Prime95 failed.  I raised voltages to 1.3v on cpu and so far it hasn't crashed.  I'm just staring from the basics.  I think I had vacation head and wasn't thinking.  Will see what I can get and repost.  I did an IntelBurnTest 1 pass and now I will let it run overnight with Prime95 and see if it stays stable then work on getting RAM to 1600 and then OC video card.  I will repost final settings.

Here is where I have it stable with 2 days on Prime 95.  Temps get to Max 81C Full Load and average Idle at 47C.  Ambient air has been high since we have been having 95-100F days this week.
 
Mother Board ( EVGA X58 FTW3 ) 
Drivers ( ?? ) 
Bios ( 83 ) 
CPU ( Core i7 920 DO )
CPU Cooler ( Antec Kuhler H20 620 ) 
Memory ( Corsair Vengeance 24GB 1600 9-9-9-24 ) 
PSU ( Corsair TX750 ) 
GPU ( GTX 560 Ti SC x 1 ) 
Drivers ( 301.42 ) 
Operating System ( Windows 7 64 Ultimate SP1 ) 


Frequency Control 
CPU Clock Ratio ( 20x (21X with Turbo On) ) 
CPU Host Frequency (Mhz) ( 191 ) 
MCH Strap ( Auto ) 
CPU Uncore Frequency (Mhz) ( 3252Mhz { 17X } ) 
CPU Clock Skew ( 0 ps ) 
Spread Spectrum ( Disabled ) 
PCIE Frequency (Mhz) ( 100 ) 


Memory Feature         
Memory Speed ( Standard ) 
Memory Control Setting ( Enabled ) 
Memory Frequency ( 1066Mhz / 2:8 ) 
Channel Interleave Setting ( 6 Way ) 
Rank Interleave Setting ( 4 Way ) 
Memory Low Gap ( Auto ) 
tCL Setting ( Auto ) 
tRCD Setting ( Auto ) 
tRP Setting ( Auto ) 
tRAS Setting ( Auto ) 
tRFC Setting ( Auto ) 
Command Rate ( Auto ) 


Voltage Control 
EVGA VDroop Control ( Without VDroop ) 
CPU VCore ( 1.300 ) 
CPU VTT Voltage ( +200 ) 
CPU PLL VCore ( Auto ) 
DIMM Voltage ( 1.60 ) 
DIMM DQ Vref ( +0mV ) 
QPI PLL VCore ( Auto ) 
IOH VCore ( Auto ) 
IOH/ICH I/O Voltage ( Auto ) 
ICH VCore ( Auto ) 
PWM Frequency ( 800Mhz ) 


CPU Feature 
Intel SpeedStep ( Disabled ) 
Turbo Mode Function ( Enabled ) 
CxE Function ( Disabled ) 
Execute Disable Bit ( Disabled ) 
Virtualization Technology ( Enabled ) **I Use VM's**
Intel HT Technology ( Enabled ) 
Active Processor Cores ( All ) 
QPI Control Settings ( Enabled ) 
QPI Link Fast Mode ( Enabled ) 
QPI Frequency Selection ( 4.800 GT/s ) 
OC Recorvery ( Enabled ) 

PnP/PCI     PCI Express 
Maximum Payload Size ( 512 ) 

I'd like to get my RAM to 1600 stable and push to 4.2Ghz stable with low temps, maybe 4.5Ghz for bragging rights ;).  After that I can get my video card back to 1000Mhz. I put it back to stock 900Mhz so I can get everything else stable.
Couple quick questions:
1. HT on or off?  I'm a gamer and a power user with testing VM's.  I read that turning it off gets cooler temps and higher overclocks.  That is how most 920's can get over 4.5Ghz stable.
2. PnP/PCI Max Payload Size.  What size?  Does it take away actual RAM usage?  If so, why on use max if it helps performance since I have 24GB RAM? Correct me if I misunderstand this feature.
3. Should I push my QPI Freq to 6.4?  I had it there on the other mobo.
4.  How do most people with on air or similar water coolers (Corsair H50/H60, Antec 620/920) get lower temps that what I have?  I have 2 Antec 120MM push-pull exhaust on radiator, exhaust stock fan GPU, 1 120MM exhaust PSU, and 1 200MM top fan.  One Thermaltake 120mm intake fan on side panel and two Antec 120MM stock front panel.  All on high and 100% on a NZXT Sentry 2 fan controller.
5. RAM Timings.  When I try to set them to 1600 9-9-9-24-2T @ 1.5v system fails.  I raised the voltage to 1.6v and still fails (as you can see I forgot to set that setting back to 1.5v above).  System is stable at 1066.  This is OC'able RAM and should be able to push it.  Is the 1066 memory controller on my 920 causing the issues?
 
Thanks in advance for the help guys!

1. I run with it on. I do Folding @ Home so I need all the power I can get. Not sure how much processing power VM's take but once we figure out why you can't overclock I suggest you try on and off.
 
2. No idea, I set it to the largest size and forget about.
 
3. No need, leave it on auto or set it manually to 4.8
 
4. Ambient room temperature? Types of fans, can be many reasons, link to your fans would help in figuring that one out. If they are just some stock fans from something that could be part of the issue.
 
5. My guess is it is your IMC. Doesn't like the load you are giving it. Increase CPU VTT to +300. Maybe even higher, like +350

Thx!  I'll try that and report back.  I'll give a list of the fans in my system with links.

LOL! Well... I'm on my tablet replying to this. My system was in the middle of first Prime95 run after changing RAM settings and voltages... it ran for about 30 mins and temps were getting to 85C and then it just shut off. I have a blue light and a yellow light by the RAM modules but nothing else. Tried to restart and nothing. Turned PSU on and off and still nada! Maybe I have a bad motherboard? I'll pull everything back out and put back on my old Gigabyte mobo since I'm dead in the water. I give it another 30 mins just in case it is a temp issue. I tried the CMOS reset button first and then fans come on but no post LED display.. time to swap mobo. Ah, the joys of geekdom! ;)

Bad motherboard. Gigabyte fired right up. On hold with eVGA for an RMA... bummer.

EVGA seems to have bad QC on their b-stock board
I've gone through 3 boards already in less then a year and getting ready to 4th from them 

I did see that on NewEgg's website. I purchased this new, not refurb. They did tell me that they will hand test a new board and they did give me a pre-paid UPS shipping label. They said they are not sending me a refurb since I am within the 30 days of purchase. I knew the board was wonky as to usually I'm pretty good at OC'ing. I'll post back with the new stable settings and maybe I can go a little higher on my OC with some help. Thanks for the post! ;)