Heatspreader for Desktop P4M?

[superkdogg]

Hey all. I'm building a P4 rig with a P4m (478) and wondering if I need to buy a broken P4 to get a heatspreader for the core, or if I could just install it like you would an Athlon XP. I'm leaning toward installing it bare, but if that is a disaster waiting to happen, let me know.

 

[RalfHutter]

Leave it bare, but be careful mounting the heatsink and make sure whatever heatsink you're using will provide enough contact pressure, since the top of the CPU will be about 1-1.5mm shorter w/o the IHS on it.

 

[xxichibanxx]

i was wondering about that also, but after reading articles on removing the IHS and some desktop cpus running w/o it, i've decided i'm going to try and mount mine w/o it. i just need a HSF now. what kind of P4m do you have and also what kind of HSF will you be using. i'm going to test out my P4 2.0c using a Asus P4P800 Deluxe and a retail Intel HSF for a 3.06proc. that i'm going to borrow from my cousin. of course, i'll be limited by my ram.

 

[superkdogg]

I have a 1.6 GHz on the way. My understanding is that all P4M's default to multi of 12 on desktop, so which one you have makes little difference. Mine is a B0 stepping that uses 1.3 Vcore at 1.6 when used in a laptop with speedstep. It wll default to 1.5 vCore and 12x100 on a desktop, but after the initial boot, I intend to go for it. FSB 166, then 200 will be set right away. FSB 200 would still only make 2.4 GHz, and this core was used for desktops up to 2.53, so it should be no prob, considering the speed binning used to get the some of the best Northwoods into the mobile market.

I'll be using a Crucial VS PC3200, so dividers will need to be reduced to avoid being ram limited. Stock Intel HSF (couldn't afford much more, besides if the chip is stock at 1.3 Vcore, I think it'll do close to 2.4 at the 1.5 desktop default-no cooling issue there). If need be, I'll stick my 80mm Tornado on the HS-it'd take a hell of a lot of voltage to get too hot with that fan.

Still working on selecting a motherboard, though. I am doing this on the cheap, so the IS7-E seems to be my best bet. I don't need SATA Raid, firewire or Gb ethernet on board (have my own add-in firewire card that would be wasted, no SATA drives, and no Gb switch or need). Otherwise I'll just drop the extra $ on the IS7 regular version. I'll need the FSB to reach minimum of 250 to hit my goal of 3.0 Ghz. My understanding is that this would be pretty good for a Northwood "B"-which is what I expect to have- a pretty good NW-B. Lemme know if anybody else has tried this project, results, etc. Thanks

 

[BroadbandGamer]

You mean to tell me people are using P4M's in their desktops? Is this the same P4M that's in notebooks or is this P4M make for desktops?

 

[superkdogg]

It's the same as a Northwood. Pentium mobile is different than P4M. The P4M is older and was basically a specially selected P4 Northwood that would run decent speeds at lowered power consumption. The Pentium Mobiles that are available now are completely different-core, packaging, pins, etc. are all different.

 

[BigBadBiologist]

I've made a few systems with these CPUs in them. You don't need a heatspreader, but you have to be really careful that your HSF makes contact with the core. For some reason some retention brackets (the black plastic things) are up higher than the core and others are fine. I've used the stock intel HSF units for most CPUs and they work fine. Since they don't have heatspreaders, they tend to run much cooler than the desktop P4's.

Once you find that your CPU is stable at 200MHz FSB, you can do a pin mod to permanently make your CPU run at 200FSB. See Here:
http://will.dashwood.me.uk/pentium4m.htm

I currently have a P4M 1.6 @ 2.58GHz in a Gigabyte VT800 chipset mobo in this system:
http://mysite.verizon.net/vze85qtq/id8.html

Also, I highly reccomend the mobile celerons. They have 256k cache (as opposed to desktop celerons) and they don't support speedstep, so their multipliers are what they should be in desktop boards which is good if you don't have a mobo that supports high FSB. They do require a pin mod to work in most desktop boards due to a difference in the Vcore settings. But they are VERY cheap on eBay (~35 for a 1.7-2.0, which should easily be able to hit 3GHz).

 

[superkdogg]

Was 2.58 the most that the CPU could do, or is there another limiting factor? 215 FSB is often where I've read that the new VIA chips peter out.

 

[BigBadBiologist]

I have a feeling it is the chipset.

 

[superkdogg]

Wow, man these things are awesome!!!

I just booted and ran some benchmarks @ 2.4 w/200 fsb.... At 1.3 vCore!!!!!!!!!!!!!!!!!

Yep, about 30 degrees Celsius ATM. Wow, never thought it would be this good!
Thanks a million for that link about these too. I had to break off the sensing pin to allow me to oc above 145 FSB. I think it was specific to my motherboard, but once I removed that pesky little devil, it's on. Thanks a million

 

[superkdogg]

Maxed out @ 2.8 GHz using 1.76 vCore. Temps around 50C under load. This was the coolest OC I've done. It doesn't even require a Tornado howling over a copper HS like my TBred @ 2.2 Ghz did.

 

[BigBadBiologist]

very nice!

 

[Acanthus]

Above 1.7v is very dangerous to all .13 intel cpus.

 

[superkdogg]

Originally posted by: Acanthus
Above 1.7v is very dangerous to all .13 intel cpus.

No worries. I went back to 2.508 GHz (209 FSB) with a 1:1 multiplier on my ram. The 300 MHz from 2.5-2.8 wasn't worth the extra voltage, and using the divider cut into the gain anyway. Still a nice setup, for a <$200 CPU/HSF/RAM/MOBO combination!

 

[lookouthere]

where do you get P4M?

 

[superkdogg]

I got mine from RichieZ in this forum You can also get them on Ebay, and by going here:
http://will.dashwood.me.uk/pentium4m.htm

Read the pages and click on the link to his auctions. I broke the pin off of mine, so what he says is legit. It really does let the MOBO detect your chip as 800 FSB.

Edit: Misspelled Richie (Sorry, R.)

 

[superkdogg]

Lookouthere: You may also want to consider a Celeron D if you're looking to build a cheap, no Hyper T system. The new Celerons are a ton better than the NW based ones. What I've read says that the low-end ones should oc to a least 3.5 GHz YMMV, of course. They also have 256 Cache, doubling the prior generation. I'd *guess* performance would be somewhat similar, depending on how much an app favors cache vs. clock. For encoding clock intensive apps, the new Celeron has great potential-especially when oc'd. If the cache and greater memory bandwidth are keys, the Mobile P4 should still do the trick.

P.S. By some careful shopping I built the following rig for less than $200.

P4-M-$43
Stock HSF-$6
GigaB-8Ipe1000 Pro-$50 Newegg refurb. (Should have waited, IS7-E went for the same price next day)
2x256 MB Corsair VS PC3200-$96 (Recycled out of AXP rig-not sure of current price)

$195-Plus case, PSU, drives. Has onboard firewire which is great considering I built this rig for media encoding.