Video card fails to initialize after overclocking CPU

[Oifish]

I've been able to overclock my Q9650 to 3.8Ghz successfully by bumping the FSB to 423 and adjusting RAM timing to 5-5-5-12, Vcore is at 1.25. (the Q9650 multiplier is locked at 9x) With this setup the system is stable without issue. I know the Q9650 and my RAM can handle a higher FSB so I increased it to 444 and everything is great, EXCEPT my video card drivers won't load. The GTX 1060 shows up in device manager with the error (Drivers failed to initialize, or something along that line). If I lower the FSB back to 423, the video card drivers initialize just fine...


Also I KNOW i can get much more performance out of a modern i3,5,7 processor, which is in the works for the future, but now I'm just curious as to why this issue is happening. Thanks all!

EDIT:
Rig Details:
OCZ StealthXStream OCZ600SXS 600W
GIGABYTE GA-EP45-UD3R
Intel Core 2 Quad Q9650 OC’d to 3.8Ghz @423 FSB
MSI GTX 1060 6GB
WD Caviar 320GB 7200RPM SATA
WD Caviar Black 1TB 7200 RPM SATA II
Pioneer DVR-212D SATA
Patriot Viper 4 x 2GB DDR2 800
Windows 10 Pro x64
Realtek ALC889A Onboard Audio

 

[LTC8K6]

PCI-E bus speed going out of spec?

 

[namx01]

PCI-E bus speed going out of spec?

That would be my guess, I had to lock mine when I had that combo with a P5B Deluxe.

 

[Oifish]

Stock is 100Mhz correct? I think it's set to "auto" right now so possible it's changing...

 

[Oifish]

Locking it at 100 seems to have done the trick. I've been able to boost the FSB up to 433 without any issues so far.