Pentium D overclock, worth going higher?

xen_

xen_

xen_

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Hello ocuk,

I have overclocked my pentium D 820 from 2.8Ghz to 3.5Ghz (200Mhz fsb to 250Mhz fsb)

To achieve this overclock I raised my fsb voltage +1, and raised my CPU voltage to 1.4v.

I am happy with this overclock however I am using 533Mhz ram and because of this overclock and the memory multiplier of 2 it is only running at 500Mhz. To get the memory to 533 I would have to raise my fsb to 233Mhz and that would make my cpu 3.73GHz. To get that speed to run stable I think I would have to raise my cpu voltage and possibly fsb voltage some more.

Has anyone here overclock a pentium D? If so how high can the voltages go before any moderate damage is done?
 
depends on cooling capacity and how well your chip was made, my 930d can do 4.2-5ghz f@h stable under water with 1.5v

however, i can only do 3.8-9 on air (freezer 7 pro)

i wouldnt advise going over 70c load tbh.
 
On my Pentium D 940 i am at 4.2Ghz but being a 900 series its 65nm, this will be cooler than the 800 series.

The temps seem a little high! My temps at 4.2ghz idle are around 39-42*C

Josh
 
xen_ said:
Hello ocuk,

I have overclocked my pentium D 820 from 2.8Ghz to 3.5Ghz (200Mhz fsb to 250Mhz fsb)

To achieve this overclock I raised my fsb voltage +1, and raised my CPU voltage to 1.4v.

I am happy with this overclock however I am using 533Mhz ram and because of this overclock and the memory multiplier of 2 it is only running at 500Mhz. To get the memory to 533 I would have to raise my fsb to 233Mhz and that would make my cpu 3.73GHz. To get that speed to run stable I think I would have to raise my cpu voltage and possibly fsb voltage some more.

Has anyone here overclock a pentium D? If so how high can the voltages go before any moderate damage is done?
Click to expand...

May I ask, what motherboard you are using ? It may be that if you simply want to increase memory speed, you can set a higher divider without the need for a further increase on the FSB.

Even Value Ram will often overclock past 533mhz, which is why I suggested looking for the memory dividers. For example, my 2GB Corsair DDR2-533 kit clocked from its standard 533 at 5-5-5-16 timings all the way upto DDR2-800 at 4-4-4-12 timings!

Also, you would need to go to 266mhz FSB, not 233mhz fsb if you want your DDR2 to run at 533mhz. From my own experience of a Pentium D 805 and a 945 chip, you *might* have a little more headroom at that voltage to clock up a few FSB further, but I wouldn't want to push it much more. With the 8xx series, if temps hit 70C you'll be looking at the CPU throttling itself to prevent it overheating.
 
Oh yeah, sorry the 233 was a typo and I did mean 266.

I am using a gigabyte DS3 motherboard.

By using the 2.66 multiplier at 250Mhz fsb it would push my memory to 665Mhz, that seems quite a high overclock for my memory, especially as my memory has no heat sinks at all.

Did you need to raise your memory voltages to get those higher clocks and better timings? I'm not sure if I should put a higher voltage through my memory with no heat sinks.


ps. cheers for fast replies :)
 
Raise voltage to 1.4? 1.375-1.4 is still the default voltage if im correct.

All depends on your temp, if its below 55 you can easely increase the voltage to 1.45 or 1.5 and the cpu should reach 4 ghz with no probs ( provided the full load temperature never reaches above 65 C )

To overclock ram you usually have to increase volts to it yes, however try a divider so the RAM runs slower than the fsb, prevents the ram limiting the overclock...

Since the 8xx series pentium d's are just 2 prescotts on 1 die, i think they have the same voltage limit as a prescott pentium 4, wich is according to another forum 1.525 volts (i see some people however, putting upto 1.575 volts to it ), but the temperature mainly is the problem on these pentiums, make sure your cpu doesnt go over 65 on heavy overclock, and not over 70 on a light overlock... ( for higher overclock cpu needs to be cooler for stability... )
 
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I would be inclined to ask what your intended use is. If it is for gaming and you have a decent vid card you probably wouldn't see that much improvement, but if your doing it to see what you can get, you should have some head room.

I have a P950 running at 4GHz without breaking a sweat - it's an older one too before they dropped to the 65nm - I get around 45-47 idle with an Arctic Cooler 7 Pro with room ambient at 22C. The older Pentium Ds have a much higher Thermal Spec than the 65nm ones and as such I wouldn't get too stressed about your operating temps until summer rolls around but like Arthalen said, be careful to not get it over 70C as you will run the risk of both throttling and shortening the lifespan of the processor.
 
snowdog said:
Raise voltage to 1.4? 1.375-1.4 is still the default voltage if im correct.

All depends on your temp, if its below 55 you can easely increase the voltage to 1.45 or 1.5 and the cpu should reach 4 ghz with no probs ( provided the full load temperature never reaches above 65 C )

To overclock ram you usually have to increase volts to it yes, however try a divider so the RAM runs slower than the fsb, prevents the ram limiting the overclock...

Since the 8xx series pentium d's are just 2 prescotts on 1 die, i think they have the same voltage limit as a prescott pentium 4, wich is according to another forum 1.525 volts (i see some people however, putting upto 1.575 volts to it ), but the temperature mainly is the problem on these pentiums, make sure your cpu doesnt go over 65 on heavy overclock, and not over 70 on a light overlock... ( for higher overclock cpu needs to be cooler for stability... )
Click to expand...


According to intels documentation 1.4v is still a safe voltage, that's why I didn't go any further. I cant use a lower memory multiplier/divider because my motherboard does not have that option.


SteveOBHave said:
I would be inclined to ask what your intended use is. If it is for gaming and you have a decent vid card you probably wouldn't see that much improvement, but if your doing it to see what you can get, you should have some head room.

I have a P950 running at 4GHz without breaking a sweat - it's an older one too before they dropped to the 65nm - I get around 45-47 idle with an Arctic Cooler 7 Pro with room ambient at 22C. The older Pentium Ds have a much higher Thermal Spec than the 65nm ones and as such I wouldn't get too stressed about your operating temps until summer rolls around but like Arthalen said, be careful to not get it over 70C as you will run the risk of both throttling and shortening the lifespan of the processor.
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My main usage is gaming and I have a 7900gt 256Mb, which does the job very well for most games now :) .

Wont high(er) voltages do any damage providing the cpu is kept at a safe tempurature? If so I may put a higher voltage into it :p.
 
xen_ said:
Oh yeah, sorry the 233 was a typo and I did mean 266.

I am using a gigabyte DS3 motherboard.

By using the 2.66 multiplier at 250Mhz fsb it would push my memory to 665Mhz, that seems quite a high overclock for my memory, especially as my memory has no heat sinks at all.

Did you need to raise your memory voltages to get those higher clocks and better timings? I'm not sure if I should put a higher voltage through my memory with no heat sinks.


ps. cheers for fast replies :)
Click to expand...

The corsair I mentioned has no memory heatspreader, yet I shoved 2.1v through it with no issues. would have been willing to risk 2.2 but no need, 2.1 was enough for DDR2-800 @ 4-4-4-12.
 
I'm running my 820 at the exact same speed- or I was at least, till my DS3 failed on me. I could get it stable above that but it tended to run hotter still as it needed a voltage boost- it's totally stable at 3.5 on the stock voltages. For me the benefit of clocking further wasn't worth the noise. Still, you can't really be unhappy with a 25% increase :)
 
joeyjojo said:
Load not greater than 65 you say? Might have to push my 805 further in that case, its 55 max at the moment.
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i dont have a intel chip but all the same try to keep full load temps under 65 ish tho =] so yep yours is good to go higher if urs is only 55
 
not sure on the voltages as i only upped mine slightly on my 805D, but you can have it running at a higher temp.
I did have mine at over 3.8ghz but the temps were too hot even with the fans in my case i have, so its now at 3.8ghz which runs nice, im sure you can get more out of an 820!
 
Ok cool. Yes it's at 3.7 now with stock volts and the 55 load I mentioned above. I might give it a little bit more voltage just to see how it responds. Probably with a huge increase in power consumption and heat :mad: :rolleyes:
 
there was an article on tomshardware about overclocking the 805D and it showed the power consumption going up a lot after a certain point, but it wasnt until the CPU was getting around 3.9-4ghz i think, and even around that they had it working within the temperature boundaries.
But they had a good chip i suppose, same one as mine which is nice!

Worth looking round if you know what stepping your CPU is to see how other people get on with OC'ing theirs
 
Power consumption/heat increases as the voltage squared. (i.e. 1v versus 2v, will be 4x more heat)

Power consumtion/heat is pretty much linear with respect to clock speed.
 
Just a mhz increase increases temp too ( this is check-able by downclocking the cpu) my pressy was 31C under full stress when @ 1.5 ghz, while its 46 C @ 3 ghz under stress ( 62C @ 4.12 ghz) @ 100% load... with a freezer...

You have to watch temps too with just a fsb increase, my old s478 pressy was 73C @ just 3.9 ghz & 1.45 volts with one of them 120mm zalmans on them...
 
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