I know the Q9550 is an "ancient" CPU but it has performed amazingly for me since 2008. For over 3 years I ran it overclocked at 3.83ghz without a single stability issue using a BIOSTAR I45 motherboard and a single Asus HD4870 graphics card. I decided to upgrade with some good deals over the holidays and installed an Intel 320 series SSD and a HD4890 to use in crossfire with the 4870. I have plenty of power with a corsair 750w power supply and AMD crossfire supports different model cards in crossfire.
The SSD and Crossfire 4890/4870 are working perfectly and have provided significant performance boosts but my Q9550 O.C. with the exact settings I've used for 3 years is suddenly unstable. It benchmarks fine although I have not ran an extended stress test, and I can't ever cause instability on purpose but relatively frequently I'll get a frozen screen and sound loop(more of just a constant noise) that requires a hard reboot.
I am wondering if anyone has experienced something similar to this and if there could be a relatively easy fix available. I have already tried modest boosts to my vcore, NB, and FSB voltages without any success. I know for sure it is not the SSD or crossfire video cards causing the instability because when I run my Q9550 at default settings I never have a problem.
Thanks in advance for anyone who can help.
3 year stable O.C. settings:
(It has been an awesome chip to o.c. so high for so long without much increase in voltages from stock).