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Can't overclock more than 10% - help please

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January 14, 2007 7:00:29 PM

Hello, I just got the following computer:

Pentium D 2.8Ghz (multiplier 14x - fsb 200mhz)
Asus P5D Deluxe
Kingstom 1GB 667Mhz
Power Supply Seventeam 420W (real)
Zalman Cooler

I was able to raise the fsb up to 220mhz without any problems.
All settings are in Auto (in bios) except for the FSB and Mem clock (which I set for the biggest value under 667mhz (did I do this correctly?)

So far, I got then 3080Mhz totally stable runing at 63C full load.

When I tried to raise the fsb to 221 mhz or higher, the system tries to boot and then it reboots at 2.8ghz (standard values).

I figured it was the vcore that was low, but I don't know what is the current vcore.
Since I only have one memory card, I undertand the system is not running in dual mode, and someone told me that for this reason the vcore is smaller than if I had 2 memory cards.

I get different readings on the vcore depending on the software I look at.
Rightmark gives me 1.362v
CPU-z gives me 1.3v - (but sometimes it changes to 3.something) Totally unreliable.

Does anyone know what vcore I should start from? What should be the highest vcore I should get? I mean I am doing in in baby steps, so I gess that 0,5v is too much to increase if I am just increasing 1mhz in the FSB. right?

Can it be the memory voltage that is low?

Please give me some clues.

Bye

More about : overclock

January 15, 2007 3:06:20 AM

Hi grbrum,

I'll try to help you out, as my system isn't too different:

PD 820 - Family F, Stepping 4, revision A0
ASUS P5LD2
4x512MB DDR2, 533 MHz
450 Watt PSU

Where you differ, your stuff is better(except maybe the PSU), so you should be able to get much nicer results than mine. Also, my overclocks are all temperature-bound, as I don't like running hotter than 56C on a passive TT Sonic Tower cooler and I run two instances of Folding at Home so my CPU is always at 100%, 24-7. I'd be thinking of getting better cooling to overclock further, but I plan on swapping out the CPU for a 4300 in the next few months.

My first experiments with overclocking were done under the JumperFree settings, where I chose Overclocking Profile. The options were 5%, 10%, 15%, 20% and 30%. I went through them all, generally with success, though the 30% boost gave me higher temps than I like. I did a bunch of memory tests and found that I was getting a pretty big bandwidth hit for not setting up the memory manually, so now I run manual.

Like you, I set the FSB frequency and the RAM, and leave everything else on Auto. My current FSB is 240 MHz and I'm running my RAM at 480 (meaning 2x240 for a 1:1 ratio). This is well below my RAM's rated speed, but I get very nice timings with it compared to any other settings, according to CPU-Z.

A final note is that whenever I overlcock at all, my Vcore goes down from ~1.36 to ~1.33. Looking at the graph using SpeedFan, my Vcore seems pretty stable, actually bouncing around less than with no overclock.

To tell you the truth, I can't imagine why you run into problems as soon as you go to 201 MHz. I'm sure there's something going on, though, and we can fix it. Can you try running some Overclocking Profiles and see if they're stable and post what CPU-Z says about your RAM speeds, timings, and the various voltages? What speed is your RAM working at when you're not overclocked?

And as for increasing Vcore, I would say you shouldn't have to do that until you're well into the 3.5+ GHz region.
January 15, 2007 3:11:29 AM

Also, the following quote seems contradictory to me:

Quote:
So far, I got then 3080Mhz totally stable runing at 63C full load.

When I tried to raise the fsb to 201 mhz or higher, the system tries to boot and then it reboots at 2.8ghz (standard values).


A CPU frequency of 3080 MHz is a 10% overclock, so with a fixed multiplier of 14, you must have had your FSB at 220 MHz for that.
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January 15, 2007 9:04:26 AM

Hello HotFoot, thank you for the response, I appreciate your help.

First, let me explain better the question in your last post.
I started at 2.8ghz then I went to 2.9, then 3ghz. then I tried 3.1 (which is 221FSB) but I rounded down to 220 - so the clock was actualy 3.08Ghz.
All this I did without any problem. All set to auto (except the FSB and memory freq.)
When I tried to go to 3.2ghz (229FSB) I put in bios 230 and the bios tried to load and it rebooted at 2.8ghz.
I would believe that this is a protection that the mobo has if something is wrong. So it booted up in default mode (2.8ghz-all auto).
So what I did is to go down from 230mhz to 220. This is how I found out that 200mhz was the high limit.

When I get hom I will check in CPUz the Mem specs for all the settings above and post here. I will try to film the boot and put in youtube so you can understand what I mean.

When you ask me to run some overclocking profiles , do you meand the 3, 5, 10% overclock and so on? I can do that and post here as well.

Questions:
-What is the most reliable source of information regarding vcore? what software really gets it right?
-Regarding the mem speed, if I run at 220FSB, then I should select 440mem freq? is that it (due to the 1:1 ratio?)? to select a higher freq would not be effective?
I always set the highest mem freq available (that is lower to the mem specs - 667mhz)
-Is it true that because I only have 1x1GB 667mhz DDR2 card, I am not working in full dual mode?
-Is it true that the vcore is reduced due to that?
-Am I still using both cores? Os is one of tem in idle mode?

Thanks again,

grbrum
January 15, 2007 1:05:22 PM

To your questions:

When you ask me to run some overclocking profiles , do you meand the 3, 5, 10% overclock and so on? I can do that and post here as well.

A: Yes, but it seems that you already know that you're stable to at least a 10% overclock. Give the 15% or 20% overclocks a try using overclocking profiles.

Questions:
-What is the most reliable source of information regarding vcore? what software really gets it right?

A: Tough question. I've used ASUS PCProbe, CPU-Z, and SpeedFan, which have all generally been close to agreement. I'd say PCProbe should be the most reliable, as it's from the manufacturer, but maybe running all three for a while you'll get a feel which two are generally agreeing and which one is an outlier.

-Regarding the mem speed, if I run at 220FSB, then I should select 440mem freq? is that it (due to the 1:1 ratio?)? to select a higher freq would not be effective? I always set the highest mem freq available (that is lower to the mem specs - 667mhz)

A: I'd stick to the 1:1 ratio if you can. The great thing about your current RAM is that it lets you go all the way up to FSB 333 with a 1:1 ratio. I expect that it will be your CPU or motherboard that will limit your overclocking potential.

-Is it true that because I only have 1x1GB 667mhz DDR2 card, I am not working in full dual mode?

A: Yes. You are not using dual-channel mode for RAM. Dual-channel isn't extremely important in most cases. I've run my RAM in standard as well as dual-channel, back when I only had two DIMMs. I didn't notice the performance difference. You should be warned that if you go out and buy a second 1 GB DIMM in the hopes of getting dual-channel to work, you might not. Make sure you get exactly compatible memory. Someone more knowledgeable in this area will be able to give you some kind of suggestion, but I'd say you're not missing that much without dual-channel.

-Is it true that the vcore is reduced due to that?

A: I doubt it.

-Am I still using both cores? Os is one of tem in idle mode?

Both cores should still be in use. Just open up task manager and see that there are two CPU usage graphs. Make sure View >> CPU History >> One Graph Per CPU is selected.
January 15, 2007 10:52:39 PM

Hi hotfoot, as I said earlier, see this movie showing my setup and boot issue:

overclocking1
and
overclocking2

you can see that is is very strange what is going on. I think it is a matter of system protection.
What am I doing wrong?

See below screen shots of CPUZ, Rightmark and PC Probe

at 200mhz



at 220mhz



Thank you
grbrum
January 15, 2007 11:05:16 PM

By the way, when I select 10% OC it does ok, when I select 15%. it does not run windows.
January 15, 2007 11:32:06 PM

First of all, very cool idea to use youtube. This really breaks down the barriers for communicating problems over the internet. It looks like your BIOS and mine are of the exact same design.

I've done a little more experimenting with overclocking today, which you can read here. I found that my particular CPU (rev A0) won't go to 3.5 GHz without 1.37 V, while it was very stable running 24/7 at 3.37 GHz at 1.33 V.

As for your voltage, you have CPU-Z and PCProbe reporting 1.31 Vcore, while RightMark is reporting 1.36 Vcore, for both 200 and 220 FSB settings. I would suspect that this voltage is actually too low for your processor. I would recommend manually setting Vcore to 1.35 (rated voltage) in BIOS. Some people have reported that letting the board automatically determine Vcore can result in too high of a voltage, but I'm sure the opposite is possible. When I let the BIOS automatically assign Vcore, it dropped to 1.33 V.

It seems your RAM is working just fine. Since you aren't pushing it beyond it's rated speed, I seriously doubt you'll have a problem. Once you do get your FSB up in the 230+ region, you might find you get better performance with the 1:1 FSB:D RAM ratio because you'll have lower latency timings. Just lowering your RAM from 667 MHz to 586 MHz brought the timings down from 5-5-5-15 to 4-4-4-12, as shown by your screen captures of CPU-Z.

As I stated above, mine is the original PD820: revision A0. Yours is the improved revision B0, which people have been able to push much further in overclocking. Each chip is unique, though. You should also note that overclocking sensitivity goes up with the number of cores in a die, as the maximum performance is determined by the weakest core. Still, that's more of a discussion for those who are pushing a 50% overclock, not us mortals with our 20-25% aspirations.

Right, so my recommendation would be to increase your Vcore to 1.35. There is absolutely no risk at this level as it is the design voltage of the part. Let me know if that helps.
January 16, 2007 7:46:41 PM

Hey. I am fully convinced that it is not my vcore that is the problem.

I used the Clockgen application for my mobo and I was able to reach 3.42Ghz (245FSB) without changing the vcore. The temperature is fine as well. Around 50C idle and 68C full work.

It is running stable as well.

Do you have any idea of what setting could be changed in order to be able to raise the clock?

I am doing some tests now. if you have any idea, please let me know.
I don't want to overclock using clockgen


grbrum
January 16, 2007 7:56:31 PM

I have no experience with clockgen, so I couldn't help you out there. Interesting that it's stable running 3.43 GHz when you're already in Windows while it won't even post when you try that kind of speed with BIOS.

Have you updated to the latest version of your BIOS? That generally improves things. It doesn't explain why it won't post to me, but it won't hurt that's for sure.
January 16, 2007 9:28:31 PM

The reason I know that clockgen worked is that the pcu temp increased on full load and I have benchmarked it with hl2:lost coast and with 3dmark05, with better results on both.

Also., I do have the latest bios.
Maybe I could downgrade and try.
boy this is getting difficult.
!