Problem Overclocking my Q6600 on GB DS4 P35

[Wigwam]

Okay I am sure I did alot of things wrong but if anyone could identify the "fatal flaw" I would be grateful.

Currently the BIOS is set to "turbo enhance for my G0 Q6600 on stock 9x266.
Stock vcore
OCZ PC6400 RAM running 15-4-4-5
EIST and C1E etc all default [enabled].

Reading that 333x9 runs at default vcore I simply jacked it up leaving everything else as is,
The machine rebooted a few times [blank screen] and then posted with the safe values back at 266x9

So what was the fatal flaw?
1) not disabling C1E/EIST?
2) not setting PCIE to 100MHz [left on auto]? - I have since set this manually to 100MHz even with the machine back on stock speed
3) not setting "performance" to standard instead of turbo in the bios?
4) Not upping the VCore?

Anything else I may have missed?

Thanks

 

[Syzygies]

I'll take door number three!

"Turbo Enhance" is at least one issue. The general principle is that Gigabyte boards can be driven stick or automatic, but not both. Turn off each "helpful" performance setting, then manually set everything.

It's overwhelming at first, but do meditate on each BIOS setting. There will be some surprises, like "Oh jeez, they made the Vdroop pencil mod a default??? What are they smoking, the customer is not always right, do they think these kids are smarter than the Intel engineers?!" And so forth. It's an education.

Be very specific on parts and BIOS settings, if you ask for more help.

Which OCZ memory? Did you see their advisory on "refresh to ACT"?

The importance of tRFC and 4/8GB of memory

I set the basic memory timings (4-4-4-15 or 5-5-5-18 depending on my DDR speed), tRD, and tRFC. Setting tRFC allowed me to back off from +0.3V to +0.1V on the memory voltage, and get stability where I was having trouble.

3.2 Ghz should be a trivial overclock once you sort this out.

 

[Wigwam]

Thanks
I last did any O/C on my Athlon XP 2500+; as you say the GB BIOS is alot more complex than my old ASUS one and the "self tuning" setup threw me somewhat.
I using bios F11 on the DS4 P35 rev 2.0 mobo
I read so much that 3GHz was given at stock that I figured I'd throw it in and see. Seeing that half-cocked failed I would appreciate more hand-holding! [read the sticky].

The RAM is OCZ PC6400 SLI-Ready 4gb kit; thanks for that link. The auto tRFC was set to 46 [so >42] but for posterity I set it to 54 [but perhaps this was foolish! - will chicken out and reset back to auto!]
The 15-4-4-5 is the speed CPUID lists at 800MHz with 2.0v and it has run at this speed since the day I built it [having upped the VDimm appropriately at the time].

 

[Markfw]

Make sure the memory multiplier is set to 2.0 !!!!!

 

[Wigwam]

ie 667MHz/PC5300?
Currently it is set to Auto [ie by SPD] so sitting at 800MHz.
I read the sticky that 1:1 is best [ie running it 667MHz] but leaving it at 800MHz shouldn't cause any problems should it?

 

[Syzygies]

Originally posted by: WigwamCurrently it is set to Auto [ie by SPD] so sitting at 800MHz.

Manually set 4-4-5-15, tRFC to 54, and see what tRD is auto, increase this by 1.

You need to restart and go into the BIOS a second time to see what tRD it picked to go with the rest of your choices. It can pick too low, that's what the Turbo was all about.

If you're running 333/800, then the SPD is choosing 2.4 as a memory multiplier. What my regressions found is this is a slightly worse factor than 2 or 2.5 or 3, but insignificantly so compared to "Am I stable?" Nevertheless, you could relax the memory, e.g. to 5-5-6-18, and switch to a multiplier of 3 for 1000 DRAM, to see if that runs any different.

For that matter, 375 * 8, etc. Make a spreadsheet and see if anything works, once you start having some successes you see a pattern that will help isolate what's causing the failures.

 

[myocardia]

Originally posted by: Wigwam
but leaving it at 800MHz shouldn't cause any problems should it?

No, not unless you want to overclock. If you decide to overclock, it isn't gonna happen until you lower your RAM's speed. BTW, there's no need in changing any of your RAM timings right now, only it's speed.

 

[Wigwam]

Originally posted by: myocardia

Originally posted by: Wigwam
but leaving it at 800MHz shouldn't cause any problems should it?

No, not unless you want to overclock. If you decide to overclock, it isn't gonna happen until you lower your RAM's speed.

Why? I don't understand this. CPU FSB is indept of speed isn't it and it is currently running asynchronously

 

[Syzygies]

Originally posted by: WigwamWhy? I don't understand this. CPU FSB is indept of speed isn't it and it is currently running asynchronously

Don't read too much into that word "ansynchronously". There are fixed multipliers available to turn FSB into memory speed, e.g. 2, 2.4, 2.5, 3... with 2.4 taking a mild speed hit.

My advice is to drive stick, don't let your motherboard set any of this automatically. It forces you to understand the options. My 4-4-4-15 memory can barely go above 800 Mhz at those settings, but up to 1100 Mhz or so at 5-5-5-18. You also need to understand tRD and tRFC to insure stability; in auto mode your motherboard can be setting either of these wrong for your memory.

There's a finite point cloud of ways you can achieve a given cpu speed, e.g 3.2 Ghz. All wisdom on the web about the virtues of various choices speak of this point cloud as if it is instead blurred into a solid body. This may be true, averaging over everyone's collective experience, but it's never true for one person on one board, attempting one cpu speed. For entirely quirky reasons your best point may defy popular wisdom, because you don't have an available point close enough to the corner everyone's urging you to use. The only way to proceed is to list all of your options and try them. First, learn how to list them.

 

[Wigwam]

well I did the failsafe: mem timings to 18-6-6-6; mem speed to x2; turned the performance to standard;
turned off EIST and C1E
now booting fine at 9x333
can tweak from this baseline then! AT least I know I have a base to play around from.
Cheers peeps. Expect more questions when I play more!