So, after settling for 195x21 for a while (since it wouldn't do 195+), I pulled the i7 920 out of my GF's machine (she wasn't overclocking it, after all) and tried that out. It does bclk of at least 200 - awesome. However, I'm running into an issue getting it stable. I can get into windows just fine, I can even run about 40 minutes of LinX, but for some reason some games run really, really slow and then crash out to Windows. The weird thing is that some games work just fine. I can play the most demanding sections of Crysis for hours without any issues. Left 4 Dead 2 and a few others, however, won't play for more than a few seconds AND exhibits terrible performance right before crashing out to the desktop.

Upping the uncore multiplier from 16x to 18x seems to fix the choppiness and buys the system an extra minute or so of stability in-game, which I found to be strange. Dropping the CPU Multi to 18x alleviates the problem altogether, resulting in a perfectly stable system. A CPU Multiplier of 19x exhibits the same performance/stability as 20x. Moving from F13h/i to F12 seems to have increased stability a little, as well. I haven't gone back to F9E, which has provided the best overall results to me so far (I plan to do that tomorrow). Basically, I'm looking for some advice in regards to getting past this hurdle. I've tried a VTT as high as 1.4v and VID of 1.376 together so far, but given that I get ~40 minutes of LinX with just 1.36, I'm not sure increasing voltages will even help. It seems as though games that partially load all four cores together, rather than fully loading one or two of them, are the ones exhibiting stability problems, but I haven't been able to confirm this completely.

I've also upped the PCIe frequency to 103 (doesn't boot higher than that), turned of PROCHOT, increased CPU Clock Drive to 1000mv and clock skew to 200ops, and disabled load-line calibration. None changed a thing.

Here are the settings I'm using - does anyone have any ideas as to 1) what might be causing the choppiness and/or 2) some idea of how to get this system stable at 20x200?

i7-920 C0 3839A
Gigabyte GA-EX58-UD5 w/F12 BIOS

CPU Clock Ratio – 20x

Advanced CPU Features:-
CPU Clock Ratio - 20x
Intel (R) Turbo Boost Tech. - N
CPU Cores Enabled - Y
CPU Multi-Threading - N
CPU Enhanced Halt (C1E) - N
C3/C6/C7 State Support - N
CPU Thermal Monitor - N
CPU EIST Function - N
Virtualization Technology - Y
Bi-Directional PROCHOT - Y

QPI Link Speed - 36x

Uncore & QPI Features:-
QPI Link Speed - 36x
Uncore Frequency - 16x
Isochronous Support - Y

Base Clock (BCLK) Control - Y
BCLK Frequency (Mhz) - 200

Advanced Clock Control:-
Base Clock (BCLK) Control - Y
BCLK Frequency (Mhz) - 200
PCI Express Frequency (Mhz) - 101
C.I.A.2 - N
CPU Clock Drive - 700
PCI Express Clock Drive - 700
CPU Clock Skew - 0
IOH Clock Skew - 0

Performance Enhance -
Extreme Memory Profile (X.M.P.) - N
System Memory Multiplier (SPD) - 8
DRAM Timing Schedule (SPD) - Quick

**The following 5 options need setting for each stick of ram**
CAS Latency Time - 8
tRCD - 8
tRP - 8
tRAS - 24
Command Rate (CMD) - 2

Load-Line Calibration - Y
CPU Vcore - 1.366 (effective)
QPI/Vtt Voltage - 1.36
IOH Core - 1.32
DRAM Voltage - 1.66

Advanced Voltage Control:-
Load-Line Calibration - Y
CPU Vcore - 1.366 (effective)
QPI/Vtt Voltage - 1.36
CPU PLL - 1.96
PCIE - 1.5
QPI PLL - default
IOH Core - 1.32
ICH I/O - default
ICH Core - default
DRAM Voltage - 1.66