Mobile P4 in a desktop board?

DellAxim

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Feb 14, 2003
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I have an extra 1.8ghz P4-M out of a Dell laptop. Is it possible for me to use this thing in a normal desktop board? It's the same socket isn't it?
 

StealthyFish

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I do'nt know. i've got a 3.06ghz P4M sittin in my dead laptop motherboard too, and i've heard that it's 478 (i've seen the screws for the socket n stuff), but some people say you ahve to do a pin mod to add it. I still don't know. Does anyone here know exactly?
 

u8myrice

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I think it's s479. You gotta buy that extension/converter from ASUS.

Correct me if I'm wrong.
 

hennessy1

Weaksauce
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Its not socket 479, thats for sure. Its a 478, and will fit in the s478 desktop motherboards. The thing is tho, will the bios recognize it and have it run correctly that is the question, because it physically will fit just like any other 478 northwood/prescott desktop cpus.
 
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Most P4-M CPUs work in desktop boards fine, with one major issue: they default to a 12x multiplier (some later ones may actually default to a 9x multiplier). So, if you want to get a decent speed out of the system, you need a board that will allow good overclocking FSB. Also, the P4-Ms don't have IHSs, so there may be contact issues for a lot of HSF units. If you do have a high FSB board and a decent HSF, then most of them hit 3GHz without problem.

If it is a P-M, it will not work in a normal desktop board without the Asus 479 adapter.
 
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the 3.06 is probably one of the ones that default to a 9x multiplier, but it should still technically "work".
 
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BigBadBiologist said:
Most P4-M CPUs work in desktop boards fine, with one major issue: they default to a 12x multiplier (some later ones may actually default to a 9x multiplier). So, if you want to get a decent speed out of the system, you need a board that will allow good overclocking FSB. Also, the P4-Ms don't have IHSs, so there may be contact issues for a lot of HSF units. If you do have a high FSB board and a decent HSF, then most of them hit 3GHz without problem.

If it is a P-M, it will not work in a normal desktop board without the Asus 479 adapter.
That was what happened to me this week when the 3.06 that I bought turned out to be a Mobile. I couldn't get the multiplier to change from it's default of 12x. I was able to get the FSB up to 200 (2.4ghz), but couldn't find a low enough divider on a Gigabyte 845PE board, so that was about it. I returned it.
 

CentronMe

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A Mobile Pentium 4-M will work on most Socket 478 motherboards, but only at 1.2GHz. You will want a 800MHz FBS to bring it up to 2.4GHz.

P4m.PNG
 

swatbat

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BigBadBiologist said:
Most P4-M CPUs work in desktop boards fine, with one major issue: they default to a 12x multiplier (some later ones may actually default to a 9x multiplier). So, if you want to get a decent speed out of the system, you need a board that will allow good overclocking FSB. Also, the P4-Ms don't have IHSs, so there may be contact issues for a lot of HSF units. If you do have a high FSB board and a decent HSF, then most of them hit 3GHz without problem.

If it is a P-M, it will not work in a normal desktop board without the Asus 479 adapter.

Correct. I would say the biggest issue is the missing IHS as that will prevent contact with the heatsink but the multiplier issue is there too. Pretty much you will just need to bump up the fsb to get some speed out of it.
 

Spazilton

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Dennis Gordon said:
That was what happened to me this week when the 3.06 that I bought turned out to be a Mobile. I couldn't get the multiplier to change from it's default of 12x. I was able to get the FSB up to 200 (2.4ghz), but couldn't find a low enough divider on a Gigabyte 845PE board, so that was about it. I returned it.

You have to be damn careful of people on Ebay selling the 3.06 processors. A lot of people will try to pass off the Mobiles as Desktops.

Make sure the stepping has a xx6xx in it. If it has a 7 its not the 533/HT.

Seen it a lot on Ebay. The genuine ones go for at least $200.
 
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Spazilton said:
You have to be damn careful of people on Ebay selling the 3.06 processors. A lot of people will try to pass off the Mobiles as Desktops.

Make sure the stepping has a xx6xx in it. If it has a 7 its not the 533/HT.

Seen it a lot on Ebay. The genuine ones go for at least $200.
Actually I purchased it from a guy on these forums. I believe it was an honest mistake, though. It was an ES that he'd bought on faith; the CPU had few markings other than a couple of numbers and the word Confidential. He hadn't actually tested it before I bought it from him. Anyways, he cheerfully took it back when I made the painful discovery. I ordered a real SL6S5 from a vendor in VT for $183 delivered.
 
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well, if it is an ES, then you may be ok because the multipliers on ES chips are normally unlocked. So if your BIOS supports it, you can probably change it to whatever you want without having to up the FSB.
 

Spazilton

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Dennis Gordon said:
Actually I purchased it from a guy on these forums. I believe it was an honest mistake, though. It was an ES that he'd bought on faith; the CPU had few markings other than a couple of numbers and the word Confidential. He hadn't actually tested it before I bought it from him. Anyways, he cheerfully took it back when I made the painful discovery. I ordered a real SL6S5 from a vendor in VT for $183 delivered.

$183 for an SL6S5 is a good deal.
 
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BigBadBiologist said:
well, if it is an ES, then you may be ok because the multipliers on ES chips are normally unlocked. So if your BIOS supports it, you can probably change it to whatever you want without having to up the FSB.
That's what I thought I could do. CPUZ showed the multiplier as 12 (23), so I figured there was some way to unlock the multiplier, but I couldn't on two Gigabyte boards, an 850 and and 845; both with the latest BIOS. I tried for hours before I just gave up. It was a shame, because I thought that I was missing something obvious. Oh well...
 
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