Am I a noob or do i have a crappy CPU that won't OC?

[DJFuji]

So it's been a while since I've OCed... the last rig I O/Ced was the good ol' CeleryA 300-450 from like '98 (remember that?)

So as a refresher, I went through the O/C guide and followed the directions there. I'm running a C2D 6400 (conroe) with a P965-DS3. 4 gigs of Corsair memory.

So I started with a really mild first OC. Took freq from 266 to 300. Several guides on the 6400 said that should be a cakewalk.

Main BIOS settings are as follows. Changes are indicated.

CPU Ratio: 8x
CPU Freq: 266mhz -> 300mhz
PCIX Freq: 100
SysMem Multiplier (SPD): Auto (3.0) --> 2.50
Mem Frez: 800 --> 750Mhz (automatically calculated from SysMem Multiplier)
DRAM Timing: Manual
Settings: 5-5-5-18 (Corsair defaults)
System Voltage: Auto
C1E: disabled
EIST: disabled

Hit save, and system booted up. Went to reboot after hitting windows and system doesn't POST.

Turned off PSU for 30 seconds and it resets back to default. Try again. This time it doesn't POST right after i change BIOS settings.

This is a very conservative O/C... most people are reporting > 3.0Ghz overclocks.

Am I doing something wrong? Heat isn't an issue -- i'm running a Thermalright Ultra 120 HSF and temps are showing at 29C in BIOS.

Any suggestions?

P.S. Am I wasting my time even trying to OC this 2 year old rig? Should I just bite the bullet and throw in a new cpu/mobo?

 

[theevilsharpie]

Try upping the voltage for the CPU.

If that doesn't work, well... overclocks aren't guaranteed, sorry.

 

[DJFuji]

I upped to 1.350v but same thing. I actually brought the freq lower... from 266 to 275 and it posted fine. Then i went to 285 and it didn't post. I've never heard of a E6400 that has this little room for O/Cing. Wtf.

I'm gonna try 1.4v @ 285 and see what happens.

 

[BlueAcolyte]

His voltage is on auto... It should actually over-volt to guarantee safety.

I recall there was some kind of problems with older gigabyte chipsets (including my own!) that prevented any kind of overclocking (non-stock settings = reset!).

IDontCare knows what im talking about. Had something to do with resetting BIOS with taking out battery.

 

[DJFuji]

Thanks Blue. Just tried 285 (7% O/C yay) and even at 1.4v it didn't POST after the initial reboot. Bah.

I'm running a corsair TX750 PSU so power shouldn't be an issue either. Maybe i just got a lame CPU? This is like getting a Celeron 300a that only overclocks to 301mhz.

Edit: I'm running the latest BIOS (F14)

 

[ExcaliburMM]

My E6400 is currently at 3.2GHz (400*8), so I definitely think the CPU isn't your limiting factor.

 

[Markfw]

your memory multiplier needs to be 2.0

 

[zagood]

your memory multiplier needs to be 2.0

agreed. Also set your memory voltage to 2.1v. I don't care if it's pink, just do it.

 

[nyker96]

your memory multiplier needs to be 2.0

at 2,5 divider and 300FSB, his memory is running at 750 which is under DDR800 spec, assuming it is DDR800 memory and not 667. It should be ok. but I agree with other poster, put 2.0v-2.1v on memory to eliminate it as a suspect.

btw, that ds3 board is very ocable, used to own one, I think fsb can do 400+. which PSU are you using on this system?

 

[cmdrdredd]

You said you're running 4GB memory. Is this 2x2GB or 4x1GB?

Using all 4 slots is harder to get stable.

 

[zagood]

Lowering the multiplier to 1:1 and increasing voltage to stock are just to remove memory settings from list of possible problems.

 

[Markfw]

Yes, I had 3 S3 boards. I just set the divider to 2.0, got PC8500 memory, and I had 2 E6300's @ 490x7 and one E6400@420x8. I used 1.4 vcore, bumped up the fsb term voltage, and they were great.

 

[DJFuji]

Markfw900, i think the default mem multiplier is 3.0 (266 x 3 = 800). If i change it to 2 with, say, a 300mhz sys freq, won't that make my memory run at 300 X 2 = 600mhz? Or am i getting this wrong?

I'm running 4 gigs (2x2) of Corsair XMS2 CM2x2048-6400C5.

And yeah, excalibur, the E6400 is supposed to be known for overclocking, which is why i'm kind of confused as to why im having so many problems...

I just don't understand why i cant even hit 300 mhz fsb and get it to post...

 

[Schmide]

http://www.clunk.org.uk/forums/reviews/14031-gigabyte-ga-ep45-ud3r-living-review-2.html

Best explanation of Gigabyte bios multipliers I've found.

 

[DJFuji]

I don't really understand that page. I looked at it, and it's just a bunch of screenshots. But i couldn't find any breakdowns of exactly what the SPD does?

Isn't it FSB * Mem Multiplier (SPD) = Mem Speed?

 

[Schmide]

The key is the memory straps and dividers image down a bit. It's a little table that tells you based on your settings what the actual multiplier and memory speed will be. The other key factor is MCH Frequency Latch above that.

What is your MCH Frequency Latch set to?

Is your memory set to AUTO timing?

It is much more than just pictures. After each screen shot is an explanation of what's going on.

 

[zagood]

schmide - 965 boards have a different bios setup than P45 boards there's no MCH latch per se.

Good overview of overclocking options with that board:
http://www.pcstats.com/articleview.cfm?articleid=2007&page=4

 

[Markfw]

So why doesn't anybody try the setting I know worked, but just argue with me ?

Whatever.....

 

[DJFuji]

Cause I already tried using 2.0 with a 300mhz fsb (600 mhz mem) and it was the same thing. No POST on reboot.

Should I go back to stock SPD (auto -- 3.0 i believe) and bump up mem to 2.1v while keeping 300 FSB?

 

[Schmide]

Just wondering have you tried a 333 fsb, maybe your board just has a hole at 300?

 

[Markfw]

Just wondering have you tried a 333 fsb, maybe your board just has a hole at 300?

I would try 400 and 1.4 vcore, they all do it easy. with a 2.0 divider.

 

[DJFuji]

i'll try 400 and 1.4 vcore and 2.0 divider. Any other settings i'll need to adjust beyond stock?

 

[MrK6]

i'll try 400 and 1.4 vcore and 2.0 divider. Any other settings i'll need to adjust beyond stock?

Give your MCH/Northbridge a notch or two in voltage as well.

 

[DJFuji]

Whoa... 400x8 w/ 2.0 divider (2x400 = 800), auto ram settings, +.3v DDR2, 1.4V CPU, and 0.2v MCH just posted and booted into windows.

Twice.

It still might not be stable but that's the first time I've got this thing to POST at anything over 275Mhz FSB. Wow.

Thanks for the tip, Mark. I'm gonna run PRIME overnight and see if it's stable. Right now speccy is reporting heat at about the same (30 degrees Celcius) but that's at boot under semi-idle conditions.

The weird thing is that the only thing I did differently this time (besides giving it a 100MHZ FSB bump) is change the MCH and Mem Voltage. Maybe I have weird memory that needs a .3v bump in order to O/C more than 15mhz?

I've done every other combination of FSB/Vcore/Divider and nothing worked. Strange...

Assuming that 400fsb is stable (3.2mhz) and is low enough in temps to be safe running 24/7, would it still make sense to upgrade to an i7 mobo/cpu combo in the ~$400 range? Or am I going to get diminishing returns as a result of this new O/C?

I'm guessing I'm probably better off upgrading the aging 8800 GT320...

 

[MrK6]

Whoa... 400x8 w/ 2.0 divider (2x400 = 800), auto ram settings, +.3v DDR2, 1.4V CPU, and 0.2v MCH just posted and booted into windows.

Twice.

It still might not be stable but that's the first time I've got this thing to POST at anything over 275Mhz FSB. Wow.

Thanks for the tip, Mark. I'm gonna run PRIME overnight and see if it's stable. Right now speccy is reporting heat at about the same (30 degrees Celcius) but that's at boot under semi-idle conditions.

The weird thing is that the only thing I did differently this time (besides giving it a 100MHZ FSB bump) is change the MCH and Mem Voltage. Maybe I have weird memory that needs a .3v bump in order to O/C more than 15mhz?

I've done every other combination of FSB/Vcore/Divider and nothing worked. Strange...

Glad to hear it booted. Your RAM voltage isn't that high, but what is the stock voltage (1.8V?). Try walking it down while leaving everything else the same and see if it's still stable. The E6400 and P965-DS3, while a great combination, won't overclock as well as some of the newer CPUs and motherboards in the C2D series (i.e, don't compare it to a Wolfdale). If you can bang out 3.4GHz on the chip, you'll be doing very well. Keep your temps <70C and your voltage <1.5V. I doubt you'll have to add more than +0.2V to the MCH, but if you feel like you're hitting a wall, go to +0.3V (make sure your airflow is good and the northbridge heatsink isn't burning hot to the touch once you do this). Generally, because it's and older chipset, the northbridge is going to be a weaker link than usual, and actually might have been what was causing a fuss with your RAM.

Assuming that 400fsb is stable (3.2mhz) and is low enough in temps to be safe running 24/7, would it still make sense to upgrade to an i7 mobo/cpu combo in the ~$400 range? Or am I going to get diminishing returns as a result of this new O/C?

I'm guessing I'm probably better off upgrading the aging 8800 GT320...

If you mainly use your rig for gaming, upgrading your video card will give you much more improvement than any new CPU could. What resolution monitor do you use?