WIP: Karaktu's (and Zap's!) Unofficial Guide to mobile Celeron overclocking success!

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rogue1979

Diamond Member
Mar 14, 2001
3,062
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Well, I had a string of bad luck lately. My Asus P4S800-MX up and died. The only replacement I had was a Foxconn SiS648. I was using an old 400MHz fsb 2.2GHz P4 Northwood at 3.1GHz.

The Foxconn board didn't let me overclock with the bios, settings were there, but it would default at 100MHz fsb every boot. So I swapped a 2.53GFHz (533MHz fsb) and it overclocked a little low, only 3.0GHz when the P4S800-MX runs it at 3.2GHz easy. But it still benchmarked 3DMark very fast, about the same as the SiS661 board at 200MHz faster.

But all of a sudden after a week, the cpu started throttling bad. No heat issues, so I swapped cpu's again and it was definately the motherboard.

Now my only backup was a POS ancient 845 chipset. It only has 400MHz fsb, not even 533MHz. But it worked like a champ, and while my gaming benchmarks were slower at 2.2GHz and 266MHz memory, it was very snappy on the desktop (only about 15% slower than 3.1GHz and 400MHz DDR on a SiS661 and Radeon 9600XT in 3DMark). I did a little research and saw the old 845 chipset had some really low memory latency, although gaming benchmarks are not as good as the 865 or later SiS chipsets.

I know I'm rambling, but now I will get to the point. I popped a Mobile Celeron 1.8GHz on the old 845 and it booted perfectly, no mods. I found a website that had a new 845PE chipset motherboard for $28 shipped. It has 533MHz fsb support and 333MHz DDR and I have a 2.4GHZ Mobile Celeron on the way. Pin mod and 3.2GHz in the bag. $28 + $53 for 3.2GHz goodness, what a deal! I am willing to bet the 845PE chipset will get very close to a SiS chipset in gaming benchmarks, even with the fsb and memory speeds limited if the cpu is running identical speeds.

I will have it up and running later next week, I will post the results. If it works, I will post a link for the website that has the $28 845PE motherboard. $81 for a cheap gaming system, not top of the line, but plenty of power for a mid-range video card like a 6600GT.
 

ghost recon88

Diamond Member
Oct 2, 2005
6,209
1
81
Update. The CPU would not POST on a P4S800 mobo. Curses to this guide, just kidding. Anyways, if you're not sure about this whole thing, google for P4-M and you mobo model and see if people have gotten the combo working or not.
 

rogue1979

Diamond Member
Mar 14, 2001
3,062
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OK, the Mobile Celeron 2.4 or 1.8 will not post by default on the 845PE motherboard.

Actually it is an MSI 6714 micro-atx. No biggie, I have several P4 desktops cpu's that I tried.
My 2.2 (400MHz fsb) was only allowed 132MHz max for 2.90GHz, it can run at least 3.1GHz on a better motherboard. But the worst thing was the memory was only running DDR 266MHz plus the overclock.

Popped a 2.53b in there and I was allowed 165MHz. Much better, 3135MHz, while the memory was running DDR333MHz plus the overclock. Sandra confirmed the memory to now be at 412MHz DDR, plus there is a pci/agp lock!

I had the 2.53b running at 168MHz fsb in a P4S800-MX (SiS661) for 3192MHz. With an overclocked Radeon 9600XT the SiS661 was beat by the much older 845PE by about 8 percent in 3DMark, in spite of the slightly lower cpu and memory speeds. Both of these chipsets were considerably ahead of a Via PM800 chipset I tested recently which worked well with Mobile Celerons.
 

Karaktu

Moderator Emeritus<br>Elite Member
Apr 24, 2002
17,752
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Originally posted by: ghost recon88
Update. The CPU would not POST on a P4S800 mobo. Curses to this guide, just kidding. Anyways, if you're not sure about this whole thing, google for P4-M and you mobo model and see if people have gotten the combo working or not.


P-M and P4-M processors are NOT mobile Celeron processors, and this guide is ONLY about mobile Celerons. All other information is interjected by others and is completely YMMV. ;)
 

rogue1979

Diamond Member
Mar 14, 2001
3,062
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Thanks for the cpu Joe. Both of the Mobile Celeron 2.4GHz I got from you did 3.4GHz on a P4S800-MX.
 

Lcarvone

Platinum Member
Sep 20, 2000
2,875
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Anyone ever used one of these CPUs ?. They are listed as socket 478 Mobile Celerons but only list as 133 fsb. The complete list seen HERE show both this version and the more common 400 fsb versions. I am wondering if anyone has had any experience with these in a standard socket 478 desktop mobo.

Thanks
 

PvSw

Junior Member
Oct 31, 2005
1
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Hey guys,

Maybe you can help me out. I consider this forum very interesting and very close to what I would like to realise.

I intend to realise something simular but with a different purpose.
I need to replace my (file)server. It now consists of a AMD K6-2 CPU (yes indeed, very old) etc. The whole system (measured at its AC input 220Volts) consumes just 35 Watt while idle. This system can only provide 2-5MByte/sec which used to be sufficient for me but now that I have started doing digital video it no longer is.

My intention is to build a new system that is about 4-6 times faster but consider its power consumption essential (it is switched on 365days/year). My notebook utilises a Pentium 4 mobile and could easily accomdate it. I need however at least 4 PCI slots for all the different interface cards.

Now after reading all through this forum I am under the impression that using an
ordinary 478 motherboard and a P4 mobile or celoron mobile at e.g. 1.6GHz I could realise such a system. After having read your article I have some questions left:

1) What would give me the least power consumption? A mobile P4 or a mobile celeron? I expect that both of these satisfy my need of CPU power. Given that I will buy a new motherboard what is currently by best choice? An Asus P4S800D-X seems close to a P4S800D that was advertised as the only motherboard recognising a celeron at 1.2 volts. Are there any motherboard that allow me to even further lower the core voltage?

The mobile CPU itself can be put in a power saving mode in which it automatically lowers frequency and changes the 5 control pins that control the core voltage. My question are:
2) Are there any motherboards that support this dynamic change of core
voltage (I assume an ordinary P4 never changes it) that you know of.
3) Are there any motherboards that support setting the CPU (I assume that is probably done using ACPI) in this power save mode that you know of?

Many thanks for the forum and hope somebody takes the time to answer my questions
 

Zap

Elite Member
Oct 13, 1999
22,377
2
81
1) At the same MHz and voltage, the Celeron would use less power because of fewer transistor count. To lower voltage you can do the voltage pin mod to give you 1.2v. There are boards that will let you lower voltage more, but they probably aren't for sale anymore. Best bets are the Asus boards... perhaps Karaktu can help here. My most recent memories of boards that allow manual undervolting are the Albatron PX845PEV Pro and the Shuttle 865PE board. Neither are being sold/made today.

2) No board supports the power saving features of the mobile P4. Mobile Celerons don't have power saving features besides the nominal voltage.

3) No.

An undervolted mobile chip should draw little power. Hmmm, if someone will buy me one of those power measuring things I can tell ya what my server draws. It is a mobile P4, overclocked a bit but undervolted, with two hard drives.

Boards with integrated video will give you a system that draws less power overall than using an AGP video card.

Another option for you would be to get a Celeron M or Pentium M with the appropriate desktop board.

Yet another option would be to get a socket 754 motherboard with integrated video, and the slowest Sempron that supports Cool and Quiet.

You can also get a VIA C3 integrated on a mini ITX board, but I wouldn't recommend that because my own C3 933MHz was pretty slow even copying files over network - my mobile P4 setup is much faster though I suspect it does use more power than the C3.
 

Karaktu

Moderator Emeritus<br>Elite Member
Apr 24, 2002
17,752
10
81
An i845pe chipset with integrated graphics is a very appealing low-power solution. Also, a SIS655 (with dual channel memory support). Chipsets consume large amounts of power these days. Plus, the fewer PCi cards you have to plug in, the less power you will consume.

As noted above, my entire HTPC setup consumes 100 - 115 watts with a mobile Celeron at 1.2v, 2.4Ghz, 2 x 512 PC3200, 2 x 400 SATA HDD, 1 x DVD-ROM, 1 x Sigma Designs X-Card and 1 x RADEON 9250 256 meg 128-bit (2 x 60mm and 1 x 120mm cooling fans) on a Sis 655-based montherboard. Just switching the video card to a GeForce 6200 is another 10 watts of power use.



 

Lcarvone

Platinum Member
Sep 20, 2000
2,875
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I am in the process of building an HTPC and plan on using one of the mobile Celerons. I need some suggestions however (in addition to the ones mentioned in Karaktu's original guide) that are

1. Low profile (going into a modified desktop case)
2. Very quiet (i.e. HTPC)

Any and all suggestions are appreciated!!
 

Karaktu

Moderator Emeritus<br>Elite Member
Apr 24, 2002
17,752
10
81
Just a minor update...

I have been testing several new motherboards with some different chipsets and will be updating (for real) the OP this week to include everyone's data. Really, the ASUS P4S800-MX and P4P800 (original) and Deluxe remain the top motherboards for overclocking these chips (IMHO!), but for cheap HTPC use or a simple low power system, just about anything will do. ;)
 

slugi

Junior Member
Nov 23, 2005
6
0
0
Need your opinions asap help me choose with these candidates:

Asus P4S800D-X or P4S800-MX SE

wich 1 is better for 1.8 mobile Celeron (C1)?
 

Zap

Elite Member
Oct 13, 1999
22,377
2
81
Do you need ATX or mATX? The mATX versions of the SiS chipset boards have traditionally been more trouble free with mobile Celerons than the full ATX versions (some people like myself have some strange cold boot problems with those). However, I'm not familiar with the newest revisions of these boards. Anyone else?
 

slugi

Junior Member
Nov 23, 2005
6
0
0
Originally posted by: Karaktu
P4S800D
- The only motherboard I have ever used that detects a mobile Celeron at 1.2v without bending the pin
- Only allows for a .5v voltage increase in the BIOS

Just a silly Q im going for P4S800D-X, (only wifi ripped of...) if it post with 1.2V an allows only 0.5V increasement
is the max V-Core 1.25V?

Please reply asap

 

slugi

Junior Member
Nov 23, 2005
6
0
0
Lack of Asus mobos on local dealer made me pick Asrock´s P4V88+ and it regoniced 1,8Mcel without tricks, default vcore is 1,6v
bios 1.4

Lets see where it bend.
 

slugi

Junior Member
Nov 23, 2005
6
0
0
Originally posted by: slugi
Lack of Asus mobos on local dealer made me pick Asrock´s P4V88+ and it regoniced 1,8Mcel without tricks, default vcore is 1,6v
bios 1.4

Lets see where it bend.

Just cutted the AD6 pin > 2,4G atm....Cpu-z shows 1.66v 166FSB next and 200....
 

sandrogalli

Junior Member
Sep 15, 2005
10
0
0
Just a quick question:

I know the mobile P4's dont give as great an overclock as the cellys, but has anyone tried a highly clocked processor in an P4S800-MX? I'm wondering whether there will be any issues with this family of processors, but no one seems to have posted about them.

Here's the spec:

http://processorfinder.intel.com/script...kgType=ALL&btnFOS=Filter+on+selections

I don't see any reason why the 0.13 micron's shouldn't work; don't know about the 90nm's tho, that's beyond my knowledge.

The reason I ask is that these chips are still cheaper than desktop chips and have a larger cache. At default fsb, there should be no stability issues at all too.

Anyone tried? If not, I'll give it a go and post back. That is, unless there's a technical issue I've overlooked in my newbieness :confused:

Thanks.
 

stevty2889

Diamond Member
Dec 13, 2003
7,032
0
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Originally posted by: sandrogalli
Just a quick question:

I know the mobile P4's dont give as great an overclock as the cellys, but has anyone tried a highly clocked processor in an P4S800-MX? I'm wondering whether there will be any issues with this family of processors, but no one seems to have posted about them.

Here's the spec:

http://processorfinder.intel.com/script...kgType=ALL&btnFOS=Filter+on+selections

I don't see any reason why the 0.13 micron's shouldn't work; don't know about the 90nm's tho, that's beyond my knowledge.

The reason I ask is that these chips are still cheaper than desktop chips and have a larger cache. At default fsb, there should be no stability issues at all too.

Anyone tried? If not, I'll give it a go and post back. That is, unless there's a technical issue I've overlooked in my newbieness :confused:

Thanks.

The problem with those higher clocked CPU's is that they default to the lowest multiplier and you can't change it. You have to OC the FSB just to get them to stock speed..
 

Zap

Elite Member
Oct 13, 1999
22,377
2
81
Thanks for the info. Been talking to Karaktu and I'll probably be re-doing this thread with all the newer information when I get a chance. Looks like we're both busy, but he's a bit busier than I.
 

hube235

Golden Member
Apr 6, 2005
1,035
0
86
Pull off the bent pin trick with success. MBM and CPU-Z reports ~1.25v and BIOS detects a Mobile Celeron. Did 133 fsb at 1.25v easily. I did run into a minor problem though. When I first started the computer up, it couldn't detect my keyboard and mouse, both of which are connected via PS/2 port. Reconnected them and restarted several times but still, none detected. It wasn't until I took the whole motherboard out and sorta shook it around. That's when it detected them again. Heh, I thought how the hell could dropping the voltage disable both PS/2 ports... Oh well. All is well right now. Thanks a bunch Karaktu. I plan on pushing it to 166 fsb and beyond!

Rig
 

buzzly

Junior Member
Dec 28, 2005
19
0
0
My first post.

Finally, there is a way to turbo-charge my old Dell Dimension 4500 (Intel D845EPT2 board). I was ready to junk the computer because it was just too slow even for my 7-year old's games. I kept it because it had a very quiet 1-fan design.

After reading this tread, I got 2 Mobile Celeron's off ebay (1.6 ($18 ship) and 2.2ghz ($30 ship)). The Dell mobo recognized both CPUs as Mobile Celeron without the bend-pin trick. I assumed the board assigned 1.3v or 1.25v to the CPU (the bios is locked down and showed no volatge info). After doing the 133fsb pin trick to the 2.2 ghz CPU, it would boot at 2.93 ghz @ 1.3v (??), but it was not stable at all. It ran fine now after the 1.6v pin mod (putting wire into the CPU socket).

Thanks OP.

Next project is to put one of these Mobile Celeron into my Asus P4G8X-Deluxe which has been running on a oc'ed 1.8a P4 running @ 2.6ghz, 1.65v.

 

Zap

Elite Member
Oct 13, 1999
22,377
2
81
Good job on that Dell and welcome to the forums!!! :thumbsup: