LGA775 memory problem

[Tech Tweaker]

I have run into an unusual problem here.

I have a Celeron 450 in one of my 775 boards (EP45-UD3P) and am attempting to overclock it.

Problem is I can't get the memory to run at its rated speed of DDR2-1066MHz. Any time I increase the memory clock speed to around or above 1000MHz the system won't boot up, but if I drop down to the next multiplier/divider lower then the system boots up and runs normally at the same FSB and CPU clock speed with no changes to any voltages. This is very odd because I've never had any issues with this memory kit running 1066MHz, and have had it above 1100MHz without any problems.

The memory is a 2GB (2x1GB) set of Crucial Ballistix .16FD3's (Micron D9), so with the right voltage and timings these should be able to run at 1200MHz+ without any problems.

They're rated to DDR2-1066 with 5-5-5-15 timings @ 2.2V, though I've found they normally run fine with just 2V. I've currently got them running at 850MHz with 5-5-5-15 timings @ 2V.

Anyone have any ideas as to what might be wrong, or a possible solution?

 

[redduc900]

What are the FSB and NB strap set to when setting the DRAM frequency to DDR2-1066?

 

[Tech Tweaker]

What are the FSB and NB strap set to when setting the DRAM frequency to DDR2-1066?

I currently have the FSB at 264MHz for an effective CPU speed of 2.9GHz.

Memory multiplier is 4.0 for 1056MHz.

I'm not sure what my NB strap is set at though.

 

[PolRoger]

I believe that memory dividers(multis) are tied to (G)MCH Frequency Latch...

200=800FSB (Quad pumped), 266=1066FSB, 333=1333FSB and 400=1600FSB.

Each latch has an associated 3 or 4 dividers with a letter to show which latch it is tied or associated with... C, D, etc.

(G)MCH Frequency Latch set on "auto" will allow you to pick any divider/multi... or the "auto" memory will pick what BIOS thinks is best.

If you manually set the latch to 266 or 333 you will only be able to pick the divider/multi associated with that particular latch.

Note that some dividers (memory speeds) may not work.. especially when running outside of the specified fsb setting (range).

 

[redduc900]

Change the NB strap / MCH latch from Auto (200C strap) to 266 w/ the System Memory Multiplier set to 4.00A (264MHz x 4.00 = DDR2-1056). You may also need to raise the FSB Termination voltage (VTT) from the default of 1.20v.

 

[Tech Tweaker]

I believe that memory dividers(multis) are tied to (G)MCH Frequency Latch...

200=800FSB (Quad pumped), 266=1066FSB, 333=1333FSB and 400=1600FSB.

Each latch has an associated 3 or 4 dividers with a letter to show which latch it is tied or associated with... C, D, etc.

(G)MCH Frequency Latch set on "auto" will allow you to pick any divider/multi... or the "auto" memory will pick what BIOS thinks is best.

If you manually set the latch to 266 or 333 you will only be able to pick the divider/multi associated with that particular latch.

Note that some dividers (memory speeds) may not work.. especially when running outside of the specified fsb setting (range).

Thanks for the information. I just checked and this is correct, changing the latch setting limits the memory multiplier settings to be only those associated with that specific latch.

Change the NB strap / MCH latch from Auto (200C strap) to 266 w/ the System Memory Multiplier set to 4.00A (264MHz x 4.00 = DDR2-1056). You may also need to raise the FSB Termination voltage (VTT) from the default of 1.20v.

Okay, tried it. Still wouldn't boot up though.

What should I change the FSB Termination voltage (VTT) to? I have no experience with it (never had the need to change it before), and don't know what a safe voltage is for that.

 

[redduc900]

Without knowing how much RAM is installed, try 1.25v to start w/ MCH Core also raised to 1.20v.

 

[Tech Tweaker]

Without knowing how much RAM is installed, try 1.25v to start w/ MCH Core also raised to 1.20v.

It's a 2GB kit (2x1GB sticks). I forgot to mention that, I've added it to the original post now.

 

[RollingThunder]

Tech,

If your Crucial RAMS are rated at 2.2V I would manually set them at that rather than at 2.0V.

That would eliminate any voltage question, no?

 

[Tech Tweaker]

Tech,

If your Crucial RAMS are rated at 2.2V I would manually set them at that rather than at 2.0V.

That would eliminate any voltage question, no?

Tried that actually. It didn't help though unfortunately.

Also, I have now tested each stick individually.

Either stick will run fine at 1066MHz and the system is able to boot up and get into the OS with no problems. It's only when I run more than one stick at 1066MHz that it becomes a problem. I'm not quite sure what the issue there is. Tried this with two different memory kits now, and the result is the same with both.

CPU just not able to support running with two sticks in dual channel at 1066MHz? Is that possible?

I'm not particularly familiar with what a Celeron is capable of, but I know I've run these sticks at 1066MHz before with multiple Core 2 Duo CPU's (E4400, E4700, E6300, E6700, E7500, E8400) and my Q6600 with no issues.

 

[Bobnova]

Vtt wise, 1.4v is fine. 1.5v is probably OK (for 65nm chips). 1.6v is likely too much.
Generally speaking, tighter timings wins over faster speeds on 775 and benching, so I'd head that route.

Those were sort of odd CPUs.

 

[RJARRRPCGP]

I have run into an unusual problem here.

I have a Celeron 450 in one of my 775 boards (EP45-UD3P) and am attempting to overclock it.

It seems as if 775 northbridges don't like anything other than 1:1.

 

[Bobnova]

Some do more than others, the memory sticks are important too. 1:1 is often preferred, especially if you can get some really tight timings with it.

Part of the issue, I suspect, is that regardless of how fast the information gets from RAM to NB, it still has to go over the FSB to the CPU.

 

[Evilsizer]

i thought i read all the thread and didnt see this, have you tried different dimm slots? since the memory controller is on the chipset, what is the chipset voltage? have you thought about better cooling for it? i dont think you would need it but adding like a 60mm fan might help if its getting to hot. it being a single core cpu, you shouldnt need high voltage. i was able to get my Celeron 420 maxed out at lowly 3.2ghz, it just wouldnt go any higher no matter what on my IP35-pro back in the day. you might want to lower the cpu multi though and go from there.

 

[Tech Tweaker]

i thought i read all the thread and didnt see this, have you tried different dimm slots? since the memory controller is on the chipset, what is the chipset voltage? have you thought about better cooling for it? i dont think you would need it but adding like a 60mm fan might help if its getting to hot. it being a single core cpu, you shouldnt need high voltage. i was able to get my Celeron 420 maxed out at lowly 3.2ghz, it just wouldnt go any higher no matter what on my IP35-pro back in the day. you might want to lower the cpu multi though and go from there.

I tried all of the DIMM slots. All run the same.

Also, I have two 80mm fans spinning at 2500RPM each cooling the chipset + VRM heatpipe.

 

[Evilsizer]

ok so lets back up, with both sticks on a 1:1 what is the max fsb or cpu speed you can achieve? with voltages set to what on the board?

 

[Tech Tweaker]

ok so lets back up, with both sticks on a 1:1 what is the max fsb or cpu speed you can achieve? with voltages set to what on the board?

Sorry, haven't had much chance to do testing on this as I've been a bit busy lately.

So far my best with this Celeron 450 is 318MHz FSB, 3498MHz CPU Core Speed. 1.39V for Vcore, 2.1V to memory, everything else at stock voltage (tried 1.26V for FSB Termination/CPU Termination (VTT) and 1.2V to MCH Core, but it didn't seem to be necessary as it wasn't helping anything to run faster or be more stable).

 

[Evilsizer]

with what cpu multi?

 

[Tech Tweaker]

with what cpu multi?

3498/318=11x

The multiplier is 11x.

The overclock seems to be heat limited though, as I've got a low end Thermaltake TR2 cooler on there (just barely better than stock). I'm hitting sustained temps of 58-62°C under load, and it doesn't seem to like that.

 

[Bobnova]

P4 stuff dislikes >60°c, especially when overclocked. That'll be at least part of the problem.

I don't think there's anything in the original TR2 series that is worthwhile.
The TR2 Bronze PSUs are better.