** Intel Pentium-M 755 & 770 Dothan Overclocking **

[Apoptosis]

I spent my Friday night catching up on the bench since I spent the past week in California for meetings then Intel's Spring IDF. I forgot I had the DFI 855GME-MGF motherboard and Intel 775 Pentium-M processor on the bench so I started to play around and overclock them. Because at midnight to 4am running benchmarks will make anyone fall asleep.

To start out I updated CPU-Z, which I noticed version 1.27.2 is out now and got the default clock speeds. A blisstering 2GHz at 100MHz FSB with a multi of 20 and DDR333 memory.


I knew i wanted to run 533MHz FSB, so I raised the FSB to 133 from 100, kept the memory divider at 5:3 (DDR442). I found the highest multi that the system would load into windows was 18.


It was at this point i tried going over 133MHz FSB and failed in my attemps. Knowing that this shouldn't be the max I spent the next couple hours trying many different brands of memory and IC's. The memory options allow 2-2-2-5 to 2.5-3-3-7 timings and no voltage adjustment, so I knew that might be a limitation. It turns out that my Engineering Sample processor was being capped at 1.280 Vcore in the BIOS. When i removed the ES CPU and put in a retail CPU the Voltage settings allowed me to bump up the core to 1.340V. Allowing me to hit the following:



Funny that the CPUID in the DFI boards BIOS locked down the ES sample, but not the retail version. I'm working on the FSB issue. Why none of my Intel Pentium-M Dothan's like much more than 133MHz amazes me. To be honest the best I got thus far is 134MHz FSB. Expect an article on this board and another on overclocking the Intel 755 processor.

So far I'm happy with my 535Mhz overclock as it is a 27% boost in clock speed while I also gained 33% on the memory and front side bus!

[infinitevalence]

slick. I was just looking at that new Asus card that alows 865pe owners to use a p-m rather than have to live with a p4 prescott that could burn up their mother board. Now all we need is DFI to drop the price on this mofo so people can acctualy afford it.

[Apoptosis]

Well I got in a retail Intel 770 processor this weekend. Thats the 2.13GHz Dothan mobile processor that runs at a default of 133Mhz for those of you that don't know. I found out that the 5:3 memory divider on the DFI 855GME motherboard is the root of all evil and fails to work over the 135MHz range. I also found out that this board has a hard on for PQI PC-3200 memory. I've tried Corsair, Kingston, Crucial, OCZ, Mushkin, PMI and others without luck when overclocking with dividers. The PQI memory for some reason works with the 2:3 divider, which is good news.

Here is the highest I can get the Intel Pentium-M 770 processor on air cooling with no volt mods. It's running with a divider of 2:3 giving PC-3400 memory at 2-2-3-6 timings. The RAS to CAS doesn't like 2 with the divider even with the brainpower PCB and Samsung TCCD IC's.



I've run some benchmarks and this sucker is fast for CPU calculations. How does 31 seconds sound for Super Pi to 1 Million places.

[Apoptosis]

It seems that the Intel 770 processor that I have tops out at 2.6GHz. This 470MHz overclock is decent as it is, but i feel the Dothan's i have on the bench have some more life left in them. Whats holding performance/overclocking back is the lack of voltage options on the mother board. The memory (vDimm) has no voltage options and the processor stops at 1.344v on both our 770 and 755 processors. The only way around this is a volt mod.

This of course voids the warranty and is best left to hard core overclockers. That said i went with the quickest and cheapest mods out there, the wire trick. For this mod to work you must locate the right pins and use a small piece of wire to connect the two pin holes in the socket. Below is the CPU Volt mod that I went with and it worked without a hitch.



Less than 5 minutes of work turns around and gives you a healthy 1.6 volts on the core. Below is our Intel 770 processor running at 167MHz FSB after the volt mod.



I'm off to re-work on the 770 and 755 processors with 1.6 vCore and see if I can get some higher FSB speeds and better performance numbers. I really need to mod the vDimm, but no easy wire trick for that one.

Also the temps are now in the 40's with 1.6V on the core. The stock heat sink is getting warm to the touch, so i might throw on some water cooling and active cooling on the north bridge tonight too.

[LVCapo]

man....awesome work. We really need to more in depth and creative articles from Nate....I think we've all been missing stuff like this and your memory articles.

[infinitevalence]

werd, you get this kind of stuff on the front page and the people will come !!

[Apoptosis]

Got all the testing done on these CPU's and am working on the article now. Here is a teaser for everyone till it is finished.



Lower is of course better and you can tell by the chart that the Dothan has the most powerfull core architecture of the bunch. The Intel 660, 630, and 570J were all tested on a 925XE board with dual channel DDR2 and HT enabled. Keep in mind the Pentium-M's have no HT, run single channel DDR1 memory and are on the 855GM chipset. Pretty Impressive!

[infinitevalence]

damn you beat my a64 at 2.6ghz by 2sec

[Apoptosis]

Well, i'm done tinkering with the Intel 755 processor. Before the volt mod i could only get 133x18 - 2.4GHz stable, but now I am able to run it at 135x19 - 2.57GHz with the extra boost in voltage.

Here is a link with the CPU-Z shot:
http://valid.x86-secret.com/show_oc?id=6781

Not too shabby as it's a 575MHz increase in frequency. Thats a 28.8% gain in frequency! An extra 175MHz for stuffing some wire in the socket isn't too shabby.

[davluks]

Hi Apoptosis, will this wire trick works with CT-479 and ASUS motherboard ? The new bios for P4C800-E deluxe does not have the option to adjust VCORE.

Thank's !

It seems that the Intel 770 processor that I have tops out at 2.6GHz. This 470MHz overclock is decent as it is, but i feel the Dothan's i have on the bench have some more life left in them. Whats holding performance/overclocking back is the lack of voltage options on the mother board. The memory (vDimm) has no voltage options and the processor stops at 1.344v on both our 770 and 755 processors. The only way around this is a volt mod.

This of course voids the warranty and is best left to hard core overclockers. That said i went with the quickest and cheapest mods out there, the wire trick. For this mod to work you must locate the right pins and use a small piece of wire to connect the two pin holes in the socket. Below is the CPU Volt mod that I went with and it worked without a hitch.



Less than 5 minutes of work turns around and gives you a healthy 1.6 volts on the core. Below is our Intel 770 processor running at 167MHz FSB after the volt mod.



I'm off to re-work on the 770 and 755 processors with 1.6 vCore and see if I can get some higher FSB speeds and better performance numbers. I really need to mod the vDimm, but no easy wire trick for that one.

Also the temps are now in the 40's with 1.6V on the core. The stock heat sink is getting warm to the touch, so i might throw on some water cooling and active cooling on the north bridge tonight too.

[conspectumortis]

Hi Apoptosis, will this wire trick works with CT-479 and ASUS motherboard ? The new bios for P4C800-E deluxe does not have the option to adjust VCORE.

Of course it works.
The vid pins (vcore) on the cpu are in a manner of speaking "jumpers".

The Bios vcore settings are only "soft"-jumpers and bridge the pentium m vids or not.

[pinguin0001]

I wanted me times for mad Tread bedannken without him I my Notebook on this achievement have brought could not. Hiermal a pair data after the change.




CPU-Eigenschaften:
CPU Typ Mobile Intel Pentium M
CPU Bezeichnung Dothan
Engineering Sample Nein
CPUID CPU Name Intel(R) Pentium(R) M processor 1.50GHz
CPUID Revision 000006D8h

CPU Geschwindigkeit:
CPU Takt 2290.72 MHz (Original: 1500 MHz, overclock: 53%)
CPU Multiplikator 15.0x
CPU FSB 152.71 MHz
Speicherbus 229.07 MHz

CPU Cache:
L1 Code Cache 32 KB
L1 Datencache 32 KB
L2 Cache 2 MB (On-Die, ATC, Full-Speed)

Motherboard Eigenschaften:
Motherboard ID <DMI>
Motherboard Name Acer Aspire 1690

Chipsatz Eigenschaften:
Motherboard Chipsatz Intel Alviso i915PM
Speicher Timings 3-3-3-8 (CL-RCD-RP-RAS)

SPD Speichermodule:
DIMM1: Hyundai HYMP532S64P6-E3 256 MB DDR2-400 DDR2 SDRAM (5.0-3-3-8 @ 200 MHz) (4.0-3-3-8 @ 200 MHz) (3.0-3-3-8 @ 200 MHz)
DIMM3: Hyundai HYMP532S64P6-E3 256 MB DDR2-400 DDR2 SDRAM (5.0-3-3-8 @ 200 MHz) (4.0-3-3-8 @ 200 MHz) (3.0-3-3-8 @ 200 MHz)

BIOS Eigenschaften:
Datum System BIOS 05/09/05
Datum Video BIOS 03/30/05
DMI BIOS Version 3A22

Grafikprozessor Eigenschaften:
Grafikkarte ATI Mobility Radeon X700 (M26-X)
GPU Codename M26-X (PCI Express x16 1002 / 5653, Rev 00)
GPU Takt 358 MHz (Original: 358 MHz)
Speichertakt 344 MHz (Original: 345 MHz)

[insane.kane]

Hi, I know it's a little out of the context of the topic, but I need some help, and you guys sound like you know what you're talking about.

I have an Intel Pentium M Dothan 760 2.0Ghz processor with an FSB of 133.0 and a Bus Speed of 533. I'm contemplating upgrading my Dell Inspiron 9300 from the crappy ATI Radeon Mobility x300 that they supply to a Geforce Go 7800GTX.

From all the reviews and guides I've read about this procedure, I understand that pinmodding a 2.0Ghz Pentium M up to 2.66Ghz is very risky, however, I also understand that the pinmod is a very important part of the upgrade.

I am then left with the option of buying and installing a 1.7Ghz Pentium M and pinmodding it safely to 2.26Ghz, or keeping the current one (which I'd prefer to do, for the simple sake of convenience). If I keep my current processor and not upgrade it, will it have a significant detrimental impact on the new GPU? Is pinmodding the only way to elevate the 7800GTX's power or is any form of overclocking fine?

Any help on this matter would be greatly appreciated.

[Pengwin]

wow, did u overclock in a laptop?

or did u overclock on a socket 479 mobo?

i have a dell 9300 and i wish i could overclock but the dell bios wont permit

[DMB2000uk]

They used a socket 479 mobo, though if your computer hardware competent you can pin mod your processor so that it runs faster...

Dan

** Edit **

Seems kinda strange to see this article again, as it was the one that drew me to LR in the first place!

[DMB2000uk]

Hey kane, Welcome to the forums, if you wanted a better/quicker reply to your question, it would have helped if you had only posted it in one thread!

But seen as though no one has replied to you, you can overclock the 7800 through the use of flashing a modified BIOS on the card (as dell has locked overclocking on its graphic cards) I can point you to some links if that doesnt daunt you (Be warned that a failed/incorrect BIOS flash will ruin your card).

But as for the CPU pin mod, its up to you, most people that pin mod had slower P-M's such as 1.86 and there was a real need to increase the power to boost the performance. If you are after the best you can get, then go ahead and get a 1.7 and mod it, however the noticable difference will be very minimal as you will probably only get a small percentage boost on framerate etc. So its up to you in the end!

Dan

[Benneh]

Hey guys.

New to this forum, also new to overclocking. I pretty much know what the word overclocking means, and i'm using a laptop. I was just wondering if there is any overclocking programs/tools that have been released for Pentium M 770 and Intel i915PM chipset. This would be much appreciated if I can get a response!

Cheers,

Benneh

[DMB2000uk]

Im afraid overclocking on a laptop is essentially a no-go with using software, plus the cooling is not usually very good so stuff tends to get really hot!

Unfortunately your CPU is already at 533Mhz FSB, so there is no 'easy' way to up it any more, aka pin mod it.

Most overclocking in desktops is fone with the bios by raising the FSB speed, but with laptops manufacturers tend to lock those so that the laptops wont melt or worse explode!

Dan

[infinitevalence]

well thats not quite true, if you have a PM with a 400mhz FSB then you can pin mod the chip to run at 533 FSB.

I thought i posted this here some where too but i cant find it amt so here is the OCF link

http://www.ocforums.com/showthread.php?t=432270

just a quick guide to overclocking a Pentium M + 915 Chipset.

[DMB2000uk]

Isnt he running a 770 which already operates at 533?

Dan