Unable to overclock Q9400

Hey, I've seen a few threads here about Q9400's, so maybe you guys can figure this out...
I'd like to first say that although I've done my research, this is my first attempt at OC'ing. Anyways, basically my problem is that I can't overclock at all. I've been following this guide at the EVGA forums for my mobo, but without any luck. I tested both sticks of memory with 2 passes of memtest86. I flashed the BIOS to the newest (P06). I initialized all the BIOS values that are stated in the guide. I set my RAM to the settings listed on the instructions that came with it (1.7V 7-7-7-20). I then ran Super PI 32M and it passed fine. OCCT ran on Mix for over 2 hours just fine as well.

Now for what I've tried:
First, I tried bumping the FSB speed from 1333 to 1400, as listed in the guide. This caused the comp to crash before getting to Windows (Vista 64), so I upped the CPU Core voltage in 0.01250 increments. I started at 1.2, and went all the way up to 1.4...same results every time. It did not seem to become any more stable with more voltage. Next, I tried changing some of the other voltages (they were all on Auto before). I tried the FSP up to 1.35, the SPP at 1.35, and the MCP at 1.6. I tried these all seperate & together, still the same results.
After all of that, I tried just changing the FSB to 1375...then 1350...nothing works. However, as soon as i set it back to 1333, everything is fine. I can still run Super Pi with no errors.

I'm out of ideas now, I've tried the smallest of OC's and all sorts of voltage combinations...there must be something I'm missing (or my hardware sucks). For reference, I've listed some of my BIOS settings that I started with, and my parts are in my signature.

**System **
CPU Freq, MHz: 2.6667 GHZ
FSB Reference Clock, MHz: 1333.3
CPU Multiplier: [8X]
PCle x16-1 & 16-2, MHz: [100]
PCle x16-3, MHz: [100]
SPPc->MCP Ref Clock, MHz: [200]
nForce SPP --> nForce MCP: [5X]
nForce SPP c-- nForce MCP: [5X]
**FSB & Memorv Config**
FSB - Memory Clock Mode: [Unlinked]
FSB - Memory Ratio:
FSB (QDR), MHz: [1333]
Actual FSB (QDR), MHz: 1333.3
x MEM (DDR), MHz: 1333
Actual MEM (DDR), MHz: 1333.3
P1: [AUTO]
P2: [AUTO]
**Memory Timing Setting**
Memory Timing Setting: [Expert]
tCL (CAS Latency): 7
tRCD: 7
tRP: 7
tRAS: 20
Command Per Clock: [2T]
**System Voltages**
CPU Core: [Auto] - 1.18
CPU FSB: [Auto] - 1.1
Memory: [1.700]
nForce SPP: [Auto] - 1.30
nForce MCP: [Auto] - 1.500
GTLVREF Lane 0: [Auto]
GTLVREF Lane 1: [Auto]
GTLVREF Lane 2: [Auto]
GTLVREF Lane 3: [Auto]

Ok, I think i figured it out. So, I noticed when I set my FSB to 1400, my Mem would set itself to 1312.5, even though it's unlinked and I have it set to 1333. This lower memory speed seems to be the cause of the unstability. Similarly, setting the FSB to 1375 sets the mem to 1289, and setting the FSB to 1350 sets the mem to 1266. Once I set the FSB to 1450, the mem set itself to 1329, much closer to the 1333 I'm telling it to be. With this, I was able to log in and run Super Pi with no errors.

I'm now up to 1550 and counting.

Just as a side note, all my voltages (except the memory) are still on Auto...the CPU is at about 1.31, the FSB's at 1.3, the SPP's at 1.35, and the MCP is at 1.5. I'm going to keep an eye on these and see how the BIOS handles them with higher FSB's.

Quite odd since underclocking the mems won't really cause any sort of instability unless the motherboard changes a few settings aside from the memclocks itself.

If you'd like to minimize your voltages, I'd suggest you set them manually unless you'd like to redo your stability tests to find the lowest possible volts your OC needs.

The problem (independent of whether it is an Nvidia or Intel chipset) is that memory and CPU communications have to be resynchronized at some point. See this link.

A WAG (wild-a**-guess) at what you see is that EVGA may have tried to optimize the memory speed (an internal BIOS calculation) while retaining the "unlinked" characteristics of the Nvidia chipsets. If this is the case, you would see the memory speed change some but always to a lower speed. Other option is that your board is bad.

I would seriously suggest you call EVGA tech support. I've always found EVGA to be one of the best orgs around with support.

Good luck.

hope the OP registered his board with them... if not then they wont help, they only will if its registered within 30days of purchase.

Evilsizer said:

hope the OP registered his board with them... if not then they wont help, they only will if its registered within 30days of purchase.

Click to expand...

Amen!