Gettin greasy ...

[mDust]

Non-blowtorch alternatives for IHS removal? I really suspect even momentary exposure to that sort of heat will degrade the part.

Do iCore processors have any embedded firmware? (I'm asking because mechanical cutting-drilling methods might generate ESD.)

I think the blowtorch is necessary to melt solder under the IHS. The solder is what holds the IHS firmly to the chips below.

I don't think any processors have embedded firmware...though I could be wrong. If you ground the IHS it shouldn't be a problem. I think you better be certain where those cores are before you start drilling/dremeling into it!

[Oneslowz28]

Note that removing the IHS will cause most current Air Coolers to not properly clamp to the CPU any more. This is because of the space the IHS fills between the die and the cooler. The result will be less than the recommended clamping pressure.

[Oneslowz28]

Oh and you can crush/crack the die also.

[Konrad]

The best info I've found (so far) is here and here.

Some people use razors to work the corners/edges off a bit.
Some recommend working on the CPU while it's warm (fresh out of the socket after stressloading) while others recommend keeping it cool (fresh out of the fridge). A few guys use high-temp torches while others use bic lighters.
Some use a mill (or even dremels or just sheet abrasives) to precision cut or grind metal away.
Some even lap to exposed silicon to mirror shine after the IHS is off.

As many people bust their i7s as succeed.
No doubt they each have different measures of skill and patience, but I think it's fair to assume that nobody wants to just throw hundreds of dollars away for the simple hell of it. For me, for now, regardless of the approach, the risk just appears to be too high to gain that potential 3-7C temp advantage.

[Kayin]

No, and no.

Also, no degradation of the part.

The degradation comes from heat because the channels in the chip will swell, actually choking electrons, causing the channels themselves to degrade. Hysteresis, causing cascade failure.

[Konrad]

By degradation I mean something that is common to all electronic parts, from humble resistors to mighty processors. No part lasts forever, they all degrade over time, some parts even while being unpowered. Not to exaggerate, of course, a decent CPU should last many years, I still have ancient Z80 and 650x parts that work well after nearly a quarter of a century. But the parts do degrade over time, they age, and thermal stresses are the surest known way to accelerate this aging. Not at all the same thing as a part failing.

So a degraded part will still work fine. It just won't have the exact value it should, it will drift, it will run a wee bit hotter or slower or less efficiently, it might even still fall within normal tolerances for a "new" part of it's kind. Degradation can be subtle and sinister and impossible to detect aside from long-term performance comparison or logging with identical parts.

I worry about an i7 because it is a very delicate, complex, dense *expensive* part. Even minor degradation can result in some particular minor and seldom-used circuit breaking or a thirst for 0.005 more volts to run stable or a loss of 100MHz ... all meaning it will not run as fast or stable as before ...

I suspect you probably already know all this, but just wanted to be clear.

Can you be confident that a few seconds of blowtorching won't degrade the part? (I would like to be before trying this!)

I know it's easy for a noob with a blowtorch to make mistakes - but I'm willing to overlook that for the moment.

I know the CPU has a generous heat threshold, after all the process of just gluing the damned IHS in place with solder was probably ~230C anyways. And it's rated to run as high as ~65C during "normal" operation, perhaps 90C before catastrophic failure. But how much aftermarket heat blasting can the part sustain before degrading?

[Kayin]

So long as you're not torching the green substrate or the LGA lands, enough blowtorch for a while.

It's low temp solder, BTW.

[Konrad]

Does the IHS contact the silicon anywhere other than at the solder joint?

[mDust]

Does the IHS contact the silicon anywhere other than at the solder joint?

It shouldn't. You can think of the solder as a TIM between the die and IHS. Because it's all designed to conduct heat away from the die, it's likely just as conductive the opposite direction also. If you're thinking about doing something like this, I'd give it a go on some cheapo eBay chips or something first before 'noobing up' an i7. I won't be trying this to avoid noobing up my own chips.

[Konrad]

I've got piles of inferior (<2.66GHz) P4 Northwoods available ... none of 'em worth more than 5 bucks these days, so I was thinking of practicing.

I'm certainly not a master craftsman (yet) but I've got plenty of confidence in basic tools (done MCU projects for years), including flame soldering SOICs and 1206 SMTs by hand, so that doesn't scare me. Busting an i7 does.

[Edit]
Now, I'm not rushing out to grab a new i7 just yet but I am targeting the i7-980X ... I'm waiting a bit because I want the 2nd gen version (1st gen products always overlook numerous bugs/flaws, and the i7-980X is 1st gen in many ways; # of cores, extreme QPI, cache size, lithography, etc)

To get a basic idea, I'm seeing the package size = 42.5x45.0mm. What are the dimensions for the die itself (after IHS removed)?

I'm asking because pyrolitic graphite isn't expensive in small wafers, but larger chunks get costly pretty quick. Example here - the PG1 and PG3 sizes are < $7, but the not-much-larger PG5 size costs $55; obviously I'd buy the cheap ones if they're big enough, and waste less material when grinding down to required thickness. I'm assuming this stuff (plus 1-2 layers of good TIM?) will be significantly superior to mystery solder plus aluminum/copper IHS. Can't tell yet what the surface is like, if it can be smoothed/honed or it's rough.

...

Any thoughts on some kind of machined nubs which use a Lego-inspired processor/heatsink interlock? Assuming machinist (or even Lego) tolerances for flatness/etc ... wouldn't it actually slightly increase total direct surface contact area? I suppose thermal expansion might be an issue (parts might "stick" when too hot?), but I really don't know if it'd be a factor within these temp ranges, especially if things are clamped.