What can I expect with a massive overclock?

If your MB doesn't support Core 2 Duo and you have DDR1, then you need to replace them anyway and it doesn't matter if you fry them along with the CPU.

If I guessed wrong and your MB and RAM are reusable, you should probably play it safe.

You will see extra performance from overclocking the CPU, just not in games. In most games the GPU decides, and a faster CPU will add very little value. (OK, there are exceptions, especially at very low resolutions.) Take a look at these charts, you'll see some overclocked $1000 CPUs getting just few fps more than a $200 CPU at stock.
http://www.legionhardware.com/document.php?id=775&p=2

You wont see 4ghz on air with stock cooling. The pentium d series cpus arent that good tbh. I had a pentium D 940 and it was slightly overclocked and I replaced it with an E2180 at stock 2.0ghz and it increased my benchmark in futuremark06 from 4000 to 7000 points without overclocking the E2180 at all. The pentium D architecture is bad compared to the core 2 duo.

Unless you are having issues with something and need a little more power I wouldnt waste my time Ocing that pentium D tbh...

I was going to replace the mobo anyway, but I was going to reuse the RAM. What are the chance I would break something else in the process. I don't want to intentionally kill my computer; I just don't mind if it does die.

My other option is to use the Pentium D to upgrade my other computer that has a Pentium 4 630. My only concern is heat. It is a Lenovo M52 8215-D1U in a micro case. It gets very warm, and there is no way that I can upgrade the cooling. So, will the PD 925 make more heat than the P4 630? Intel's site says that their Thermal Specification are 69.2C (630) and 63.4C (925). What does this mean?

Pentium D can go to 4.1GHz super easy http://www.tomshardware.com/reviews/dual-41-ghz-cores,1... on air cooling, I wouldn't recommend going over 4.0GHz though since the power usage climbs a lot. It requires a heavyduty air cooler to do so though and good cooling throughout the case, but if you stay at around 3.8GHz you will do fine on an air cooler and at 4.0+GHz even the Reserator watercooler system works wonders, thats what I used back then when I ran this wonderful chip.

Probably not too much I'm afraid. Here is an old PC stat review of that CPU overclocked

http://www.pcstats.com/articleview.cfm?articleid=1988&p...

but really I think they tried clocking it too high and experienced some CPU throttling. Anyway make sure you cool it properly if you're going to overclock it. At 4GHz you may get around the same performance as a Pentium E2160. Still, it will be a somewhat noticable improvement. Just make sure that it is properly cooled or your CPU will throttle and you will begin to loose performance.

The P4 630 has a TDP of 84W:
http://processorfinder.intel.com/details.aspx?sSpec=SL7Z9
and the P4 D 925 has a TDP of 95W
http://processorfinder.intel.com/details.aspx?sSpec=SL9KA

So the P4 D 925 (dual core) benefits from the 65nm manufacturing process as it has maximum dissipation of only 10W more than the older 90nm P4 630 (single core).

If you look at the numbers for the P4 D 960 you will see it has a TDP of 130W !!!
http://processorfinder.intel.com/details.aspx?sSpec=SL9AP
to achieve 3.6 Ghz vs. 3.0Ghz and has a raised VID (process power dissipation is dependent on V^2 and f obviously). 1.3V (960) vs. 1.225V-1.312V (925).

Raising the frequency on the P4 D 925 is going to raise the power dissipation a lot and could potentially fry the PWM CPU voltage converting MosFETs on the motherboard (so it is worth checking it can take a 3.6Ghz P4 D 960 before overclocking)!! The other problem is that the CPU may have to start thermal throttling which was an issue with the 3.6Ghz P4's. Essentially the CPU is chucking out so much heat that it cannot be removed from the case quick enough and the CPU has to drop down clock frequency to maintain thermal stability.

If you want to use the P4 D 925 in a micro case it should be OK at stock. Would that be with a different mobo though? If so you need to check it supports the dual-core 65nm P4s...

Bob

With the proper components you will be able to achieve an OC of 1ghz.

Why not just leave it alone and give it to someone else, or keep it as a backup computer when yo do upgrade?

I agree with runswindows95, you really wont benefit ocing that chip enough to justify frying a perfectly good chip. I dont think its so good of an idea to try to oc that chip 1ghz on stock cooling. I believe you said you didnt want to spend the money on an aftermarket cooler which is fine. You can oc it to a degree on the stock cooler but I would rather keep it around 400mhz increase. Some do oc with stock cooling more than that but I prefer not to. Id rather be able to use that chip in another system such as a media center setup or sell it on ebay and get some money back out of it.

Build a spare rig with it and sell it or give it to a family member. My parents and my sister benefit from my upgrades. None of them have bought a pc in the last 6 years due to my frivilous spending on upgrades.

If you decide to send that cpu to death row, then at least spend 30 bucks on an aftermarket cooler to give it a respectable death or a decent chance of survival...

You can expect to become a OCing junkie... i've already started down the path  

its fun though pushing things way past their limits... just have to go water and i'll be set  

That Pentium D is a good place to start overclocking. I loved my old Pentium D930, had it overclocked to 4.6ghz (This was using liquid cooling). For the time it was ridiculously fast.

You will want to replace EVERYTHING if you go down this path.
Sell your current system and use the funds to help finance your next build.

Alternately, try OCing your system.

But you the new chip requires a new mobo.
You also require new RAM.
You Video card will not even fit in new Mobos.
Based on the age of your system, it's time to replace the power supply.
Considering the the HDD is the slowest part of the system, it would be wise to place that as well.

Sell and build fresh.
Or just OC what you have.

Alright, since I don't really want to kill it, and I don't even know if my cheap mobo can handle it, I've decided not to OC.

Can you give me advice on this then? (I know I already asked this.)
My other option is to use the Pentium D to upgrade my other computer that has a Pentium 4 630. My only concern is heat. It is a Lenovo M52 8215-D1U in a micro case. It gets very warm, and there is no way that I can upgrade the cooling. The heatsink on the processor and chipset burn to the touch with the P4. I can't replace the heatsink or add any fans. So, will the PD 925 make more heat than the P4 630? How much heat can the PD take?

Read my previous post again (why ask questions if you aren't going to even bother reading the answers)...!!  

The difference is like only 10W in total power dissipation because the 925 is newer tech. (even despite it being dual core). You have to check whether the MB in the Lenovo case actually supports a dual core (65nm) presler P4 (possibly with a BIOS update).

Bob

When you say that about the total power dissipation, are you implying that they are similar in temperatures? It's confusing me, because you're measuring Watts not temperature. According to the Lenovo website, http://www-307.ibm.com/pc/support/site.wss/document.do?... it will support the processor.

OK that's all good (that it is compatible)!!

There is (roughly) a linear relationship between the wattage of heat dissipated by a aircooled heatsink and the temperature rise. If you look at the spec. for a typical heatsink for example:
http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=185&products_id=24549
The figure is 0.14C/W thermal resistance.

84 watts dissipation = 11.76C delta (i.e. above ambient temperatures)

95 watts dissipation = 13.3 C delta

Of course you don't get that because the bond between the heatsink and CPU heat spreader will have a less conductive material filling the air pockets between them. Definitely worth using MX2 or similar highend thermal paste with such a high power dissipating CPU...
http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=58&products_id=22176
You want the CPU heatsink to get as close to the temperature of the CPU as possible - i.e. hot!!

Bob

There is really no way to upgrade the heat sink or case fans. The cpu has a large heat sink with a bunch of parallel blades, and it uses two 60mm case fans. I have put Arctic Silver thermal paste on the heat sinks. The cpu and chipset heat sinks are very hot to the touch and the top of the psu burnt my fingers. I think that the heat is defiantly getting to the heat sink, but it's not able to get out of the case. The only case fans are the two front 60mm fans and the psu fan. Even if I didn't upgrade the processor, I'm still concerned for the computers lifespan.