845 Board to downclock vcore on a pentium M?

I searched for a little while and saw a handfull of people mention mods that people did to lower the vcore on 845 boards so the Pentium Ms ran at default voltage but couldnt find the actual mod anywhere =(

Whats the lowest vcore selectable on a good 845 board?

If your board BIOS doesn't let you undervolt your CPU, you'd probably have to voltmod the board.

canadianpsycho said:

If your board BIOS doesn't let you undervolt your CPU, you'd probably have to voltmod the board.

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The VID pin trick? Can you do the same thing with a Pentium-M? If so thats fine by me as Ive done that a good amount of times with Xeons. Anyone have the pin outs of a Pentium-M?

Both the Albatron PX845PE Pro II and their PX865PE Pro II allow voltages lower than "stock". The 845 allows voltages down to like 1.2, the 865 allows voltages down to a whopping 0.825.

I've owned both, and they're both excellent overclocking boards. I ran a 2.4C at 209FSB on the PX845PE Pro II board for 24 hours with hyperthreading enabled -- dual prime stable. Can't tell me that unvoltmodded stable 209fsb on an 845 chipset isn't pretty nice...

I also used that same 2.4C to hit 295FSB on the PX865PE Pro II board, although it loses stability somewhere around 288FSB. Certainly not bad, but not as much as I wanted I'm voltmodding my spare 865 board now and having good luck with it.

Albuquerque said:

Both the Albatron PX845PE Pro II and their PX865PE Pro II allow voltages lower than "stock". The 845 allows voltages down to like 1.2, the 865 allows voltages down to a whopping 0.825.

I've owned both, and they're both excellent overclocking boards. I ran a 2.4C at 209FSB on the PX845PE Pro II board for 24 hours with hyperthreading enabled -- dual prime stable. Can't tell me that unvoltmodded stable 209fsb on an 845 chipset isn't pretty nice...

I also used that same 2.4C to hit 295FSB on the PX865PE Pro II board, although it loses stability somewhere around 288FSB. Certainly not bad, but not as much as I wanted I'm voltmodding my spare 865 board now and having good luck with it.

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Thats pretty tight. Im definitely going to get a Pentium M. Seem to be a lot of "working pull" ones from dead laptops.

Thing is I will probably just get what ever 845* board I can get for cheapest on ebay that has integrated video. Do you know anything about how to mod the board/socket so I can get lower than stock voltage?

Basically all "standard" 845 chipsets are going to stop at 1.525v and go no lower. There is no mod, because there were no P4 desktop processors that needed less than 1.525 volts.

Also, the normal Pentium M chip (socket 479) cannot be used in a Socket 478 motherboard. The pinouts are completely different than a standard Pentium 4, besides the fact that two or three of the pins don't line up right either.

You CAN use a mobile P4 in a standard P4 desktop motherboard, but you will again run into voltage issues. If you are going to do that, I also suggest you buy an 865 chipset motherboard because the mobile P4's default to a 12x multiplier when installed in a desktop board. You'll need a LOT of front side bus to get it back even to stock speeds...

Albuquerque said:

Basically all "standard" 845 chipsets are going to stop at 1.525v and go no lower. There is no mod, because there were no P4 desktop processors that needed less than 1.525 volts.

Also, the normal Pentium M chip (socket 479) cannot be used in a Socket 478 motherboard. The pinouts are completely different than a standard Pentium 4, besides the fact that two or three of the pins don't line up right either.

You CAN use a mobile P4 in a standard P4 desktop motherboard, but you will again run into voltage issues. If you are going to do that, I also suggest you buy an 865 chipset motherboard because the mobile P4's default to a 12x multiplier when installed in a desktop board. You'll need a LOT of front side bus to get it back even to stock speeds...

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According to some of the Sspec info some are 478 and some are 479 - http://processorfinder.intel.com/scripts/default.asp?chrid=942

There are a few sspec update releases intel did that I found when I searched for a specific 1.3ghz 1mb cache P4M that showed it as socket 478 though. SL6N4 was the stepping. Not really sure whats going on there...

If the multiplier is forced to 12 thats fine by me. Im looking at a 1.3 or 1.4ghz mobile. I want to make this a completely passive router/weak FaH box.

The reason why I was looking at 845 boards is I read somewhere, pretty sure it was these forums when I searched for Pentium M, that you couldnt use them in anything above the 845 boards...

Does anyone have a Pentium-M in a 865 board?

Ok, please make sure you're using the nomenclature properly:

The Pentium-M is the processor used in Centrino Technology laptops and comes in speeds between 1.3ghz and 1.7ghz. No matter the number of pins, this processor can NOT be used in a socket 478 desktop motherboard. The pinouts are completely different and you will destroy the chip, the board, or both.

The Pentium 4M is a standard P4 processor with the slight addition of Intel's SpeedStep technology. It almost always comes in socket478. These chips can be used in a standard desktop motherboard provided you don't mind the low multiplier that it will default to.

They are different processors, and you mentioned them both in your previous post. Make sure you know which one you're dealing with, because a true Pentium M will not work in a desktop 845/865/875 motherboard. As for the chipset, either chipset (845, 865) should take it just fine.

Albuquerque said:

Ok, please make sure you're using the nomenclature properly:

The Pentium-M is the processor used in Centrino Technology laptops and comes in speeds between 1.3ghz and 1.7ghz. No matter the number of pins, this processor can NOT be used in a socket 478 desktop motherboard. The pinouts are completely different and you will destroy the chip, the board, or both.

The Pentium 4M is a standard P4 processor with the slight addition of Intel's SpeedStep technology. It almost always comes in socket478. These chips can be used in a standard desktop motherboard provided you don't mind the low multiplier that it will default to.

They are different processors, and you mentioned them both in your previous post. Make sure you know which one you're dealing with, because a true Pentium M will not work in a desktop 845/865/875 motherboard. As for the chipset, either chipset (845, 865) should take it just fine.

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yeah just got that after I posted. That blows. Only thing I could get is a 855 desktop board thats like 350$ because its imported from somewhere in Europe =( SOB! I dont want a downclocked low voltage P4...

If you want a cheapy high FSB OCer, try a celeron, or those new 2.4As... Some of them are overclocking pretty well, and aren't HT chips.

canadianpsycho said:

If you want a cheapy high FSB OCer, try a celeron, or those new 2.4As... Some of them are overclocking pretty well, and aren't HT chips.

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Might even just go with a .13u PIII

Anyone know of a board like the Abit TS20? Only place I can find it is a scam store from pricewatch. Its listed as a microatx board but its some embedded board Im guessing. 1U style.

Hey, try looking for a nice cheap P4 1.8A... There's a ton of those things in C0 and D1 steppings that would do 3+ghz on halfway decent cooling. You can pick them up for like $50 as Dell pull. I had one that did 2.85ghz at 1.63v, Larva on this board has one doing 3.4ghz on 1.75v, more than a few people have them doing between 3ghz and 3.2ghz here on this forum (all on air cooling)

You can get them BRAND new for $109 retail, so here's an idea:

Grab a cheap 1.8A for probably $50
Grab a cheap 845 motherboard (Alby makes one called the PX845GE with integrated video) for like $50
Buy 512mb of cheap PC3500 ram for like $75
Buy a ghetto case and cheap 300W PSU for like $50 at most

There ya go, probably a 3ghz rig / 166FSB with ram at 415DDR for right around $200.

Albuquerque said:

Hey, try looking for a nice cheap P4 1.8A... There's a ton of those things in C0 and D1 steppings that would do 3+ghz on halfway decent cooling. You can pick them up for like $50 as Dell pull. I had one that did 2.85ghz at 1.63v, Larva on this board has one doing 3.4ghz on 1.75v, more than a few people have them doing between 3ghz and 3.2ghz here on this forum (all on air cooling)

You can get them BRAND new for $109 retail, so here's an idea:

Grab a cheap 1.8A for probably $50
Grab a cheap 845 motherboard (Alby makes one called the PX845GE with integrated video) for like $50
Buy 512mb of cheap PC3500 ram for like $75
Buy a ghetto case and cheap 300W PSU for like $50 at most

There ya go, probably a 3ghz rig / 166FSB with ram at 415DDR for right around $200.

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Im thinking more along the lines of tiny and quiet though. Even 1.8ghz is a waste for me as its just really a router. Not that I wouldnt love to have a 3ghz box to run FaD at the same time but the whole point of me building this box and replacing my folding farm is to cut back on power consumption, heat output, and noise.
Initially I was looking at a Via Eden board but those SOBs are expensive... 200$ for the board and a proc that I can beat at doing integrals... Hence why IM looking at an old flex-atx P3 board now

Wait -- you're just looking for a software router box? Seriously? It's gonna do NOTHING else and you just want low-power and quiet?

Dude, P3's are seriously overrated. The 2nd layer of my DMZ (network address translating and routing for internal network, 2nd layer firewalling for my IIS box and my Telnet server -- all at home) is a Pentium Original 166mhz with 192mb of non-EDO ram. It's actually an HP Vectra XA box, and has been running for like 170 days straight without a reboot on WindowsXP Professional and a 2gb harddrive.

That goofy P-166 box can sustain about 14mbit of traffic, even though my cable connection is 3mbit/512k at absolute most (business connection) so it's more than enough... I have no monitor, no keyboard and no mouse attached to it, only a power cord and two network cables. A 3Com 3C905b card connects the box to my internal network, and the built-in AMD ProNet 10/100 nic connects it to my external/DMZ network.

It uses an 85 watt (max) powersupply, and other than the two nic cards, it also has a PCI Matrox Millenium 2064W 2mb card in it (because otherwise the machine won't finish POST). I manage it by terminal services only...

I think I built that machine for like $50 and I haven't put a dime in it since.

Albuquerque said:

Wait -- you're just looking for a software router box? Seriously? It's gonna do NOTHING else and you just want low-power and quiet?

Dude, P3's are seriously overrated. The 2nd layer of my DMZ (network address translating and routing for internal network, 2nd layer firewalling for my IIS box and my Telnet server -- all at home) is a Pentium Original 166mhz with 192mb of non-EDO ram. It's actually an HP Vectra XA box, and has been running for like 170 days straight without a reboot on WindowsXP Professional and a 2gb harddrive.

That goofy P-166 box can sustain about 14mbit of traffic, even though my cable connection is 3mbit/512k at absolute most (business connection) so it's more than enough... I have no monitor, no keyboard and no mouse attached to it, only a power cord and two network cables. A 3Com 3C905b card connects the box to my internal network, and the built-in AMD ProNet 10/100 nic connects it to my external/DMZ network.

It uses an 85 watt (max) powersupply, and other than the two nic cards, it also has a PCI Matrox Millenium 2064W 2mb card in it (because otherwise the machine won't finish POST). I manage it by terminal services only...

I think I built that machine for like $50 and I haven't put a dime in it since.

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LOL yeah I know a P3 is overkill. Im making this project more than just a router. Well functionality wise yeah its gonna just be a router. But when I can get a P3 board with dual nics, integrated video for 40$ delivered why not? I've also got some other plans for this project but dont wanna give them away till Im done