Overclocking the unoverclockable.

[Unfocused]

I've got an Intel D845PESV mobo and a Pentium IV Northwood 2,8Ghz processor (533FSB version). There are no overclocking options in this mobo's BIOS. Wherever I looked, people said it's impossible to overclock with this mobo.

However, I found this ClockGen application which supported PLL's used in some Intel boards (not mine, though). I decided to give it a try with the Cypress CY28346 used in the Intel D845GBV and D845EPT2 mobos. It worked! The program was able to read the clocks and modify them.

On first attempt I tried 3Ghz. No problems here, system stable etc. I loaded up CS:S and BF2142. Additional frames, yay!

Then I tried 3,2Ghz. Worked for a while then I got a BSoD and the system restarted a few times until it changed back to 2,8Ghz. Back to 3Ghz - I set it and click apply, this time the system reboots without a warning, but the CPU is working at 3Ghz so all's good.

Next attempt - about 3,1Ghz - I click apply and there's a ****ing loud beep in my headphones (not the PC speaker). Uh oh, I reach for the reset button.

So far 3Ghz seems the maximum stable setting. However, today the application was giving me problems, it seems. My brother was using the PC in the morning without a problem. He turned it off after he finished and I turned it on about 30minutes later. After choosing the profile and a few seconds the PC crashed (or actually acted as if it was under really heavy load, the cursor moved every 20 seconds when I was moving the mouse). I did a reboot, got a "choose proper boot device" sort of message, and the cure to this was to plug out and back in the power cable to the HDD (making me think it was a HDD problem but turns out it wasn't). After a few resets I chose another Windows profile, got a "failed to initialize driver" from Clockgen, renamed the folder it was in (so it wouldn't start upon logging to my profileand crash my PC) and relogged to my profile. I manually started clockgen, set 3Ghz as usual, and everything's OK now. So, kinda wtf really.

Back to the actual overclocking - isn't 3Ghz a bit weak on a 2.8Ghz Pentium? I know that software OC is not as effective and safe as hardware OC (BIOS), but still - is there anything I could do to bring the clock a bit higher? The CPU temperature is fine BTW, no overheating.

 

[The Brick]

Yeah it's probably your mainboard that's holding it back. It could also be the ram, though less likely with such a tiny increase.


Btw, what values can you change?

 

[NeptuneUK]

My 800mhz fsb LGA775 Pentium 4 went from 3Ghz to 3.8ghz on air cooling with value DDR2 ram. I ran DoD: Source for 30 mins too to prove it was stable.
Go me!

 

[Unfocused]

Yeah it's probably your mainboard that's holding it back. It could also be the ram, though less likely with such a tiny increase.


Btw, what values can you change?

Unfortunately, there's this slider that adjusts a few values simultaneously. So not much control ;/

Screenie

 

[The Brick]

Hmm no individual control won't get you very far. The trick in overclocking is to remove most load on the mainboard by switching off unnecessary features, then make sure the PCI bus and AGP bus are locked. Then you are free to fiddle around with memory timings, multipliers and fsb. As the makers probably knew it sucks for overclocking so they just didn't support it. Sorry.

 

[Unfocused]

Hmm no individual control won't get you very far. The trick in overclocking is to remove most load on the mainboard by switching off unnecessary features, then make sure the PCI bus and AGP bus are locked. Then you are free to fiddle around with memory timings, multipliers and fsb. As the makers probably knew it sucks for overclocking so they just didn't support it. Sorry.

Why should the PCI and AGP bus be locked? BTW, in the "PLL setup" window (check screenie), if I check the "Ignore GSB/PCI" box and then click "read clocks", then the PCI and AGP clocks won't be read and shown in the "PLL control" window (what means they probably won't be modified). Should I try that?

 

[The Brick]

Yes try that, I read here that that does the trick.
http://www.cpuid.com/clockgen.php

 

[Unfocused]

Yes try that, I read here that that does the trick.
http://www.cpuid.com/clockgen.php

Ah yes, I saw that, but I thought that I should check it only if I can't read the clocks at all, not that it will help in stability etc.

Still, why is it recommended to lock the PCI and AGP clocks?

EDIT: Hm, tried 3,1Ghz with the PCI/AGP locked and got those strange noises coming from the soundcard again (weird, really, since generally warning beeps come from the PC speaker).

 

[The Brick]

Because the AGP card can't handle the speed, the PCI devices will crash, and the southbridge on your mainboard won't be able to handle it. Then your IDE and SATA devices will malfunction as well...

 

[hungryduck]

make sure you stress test with something like: http://sp2004.fre3.com/download.htm
you computer may run "Stable" but it still could be generating errors.....

 

[Asus]

When you OC the FSB the other buses go up with it. You would be OCing the AGP/PCI buses which will also effect the data flow of your harddrive. Basicly you could corrupt data and/or crash your PC if it goes too high. Locking the buses from the FSB will make it so you are only OCing the CPU/Memory.

 

[Unfocused]

Oh well, regardless of ignoring AGP/PCI in ClockGen, the system:

-runs stable at 3Ghz,
-crashes while making strange noises at 3,1Ghz,
-runs for a few minutes at 3,2Ghz, then it resets itself (as if I pushed the reset button)

So I guess I won't have much OC fun with this one.

BTW, I think CPUFSB and CPUCool applications may support the PLL that works with my mobo, but they crash my PC when I start them ;/

 

[NeptuneUK]

Dont use stock cooler

 

[Unfocused]

Dont use stock cooler

CPU is not overheating.

 

[hungryduck]

CPU is not overheating.

it's okay, I used the stock cooler on my AMD x2 3800+ plus and was able to overclock to 2.4ghz (from 2.0) just fine. Just make sure you monitor those temps, just in case.....