The real reason delidding improves CPU temperatures

[JoostinOnline]

There is a common misconception that the reason delidding a CPU and replacing the thermal paste is because Intel uses low quality TIM (thermal interface material).  While there is some truth to it, the main reason for the temperature drops is the removal of the adhesive that holds the IHS (integrated heat spreader) and PCB together.  Removing it reduces the gap between the IHS and the die itself, meaning heat doesn't have to transfer between such a thick layer of TIM, as shown in this diagram:

 

Credit to ekwb.com for the diagram

 

The thermal paste that Intel provides isn't actually that low quality.  While it definitely doesn't perform as well as higher end thermal pastes or liquid metal (just replacing the pre-applied TIM with MX-4 on a 4790K got me a 7C drop), it lasts much longer.  This is a very good trade-off.  It would be very bad for Intel if the TIM wore off after a year or less.

 

In mid-2016, Linus did a delidding video that made many of his fans believe there was actually little benefit to delidding.

His tests showed almost only a 3C drop in temperatures after delidding.  Some blamed it on the fact that he used cheap TIM (which must have contributed somewhat), but it doesn't explain why most people get around a 15-20C drop.  The culprit can be found about 5 minutes into the video: the excess adhesive. 

 

At no point after that does he properly remove the adhesive.  This can be seen in later shots, although the images are less clear..  The gap remains between the CPU die and IHS, meaning the main problem isn't solved.  When placing it back together, you can see a gap between the IHS and PCB, instead of sitting flush like it should:

 

When delidding, you will have to replace the TIM, as it's useless once you've separated the IHS and CPU.  However, it is very important that you also remove the adhesive.  This can safely be done with an old credit card, or your finger nails.  Hopefully this clears up confusion, and lets you get the most success when delidding.  If you apply new adhesive, I recommend putting the CPU back in the motherboard before it dries, to reduce the gap between the IHS and die as much as possible.

 

PS: I know it may appear that I am trying to speak ill of Linus, but I want to emphasize that I have great respect for him.  I have learned a great deal from his videos.  There was just a mistake in one of them that perpetuated a common misconception, and I wanted to clear things up.

[Tim613]

seems like delidding has done a great help for x299 form what i hear

[Wonders3004]

actually been thinking about doing this to my 7700k just havent gotten around to it thanks for pointing this out. do you think a good lapping to the IHS while i have it off would be a good idea

[JoostinOnline]

2 minutes ago, Wonders3004 said:

actually been thinking about doing this to my 7700k just havent gotten around to it thanks for pointing this out. do you think a good lapping to the IHS while i have it off would be a good idea

I wouldn't.  It's already perfectly flat, and some rubbing alcohol helps remove the final bits of adhesive. 

[TheGlenlivet]

23 minutes ago, Wonders3004 said:

actually been thinking about doing this to my 7700k just havent gotten around to it thanks for pointing this out. do you think a good lapping to the IHS while i have it off would be a good idea

I delidded my 7700K and applied liquid metal, but didn't lap or resurface the die in any way.  At full load on all cores it would sit in the 90s and touch 100 degrees with a corsair h110 on it at full blast.

Delidded, it now sits in the 70s and hits 80 occasionally.   This is at 4.8GHZ and 1.23 v.  I know others have gotten higher speeds and lower temps, but the delid is worth it, even if you leave it stock..

[Wonders3004]

1 minute ago, TheGlenlivet said:

I delidded my 7700K and applied liquid metal, but didn't lap or resurface the die in any way.  At full load on all cores it would sit in the 90s and touch 100 degrees with a corsair h110 on it at full blast.

Delidded, it now sits in the 70s and hits 80 occasionally.   This is at 4.8GHZ and 1.23 v.  I know others have gotten higher speeds and lower temps, but the delid is worth it, even if you leave it stock..

yeah im on a custom loop and it usually sits about 70 under load and sometimes spikes up to the high 80s i had to roll my oc back to get the messages to stop popping upi have some liquid metal already maybe ill do it this weekend thanks for your replies.

[JoostinOnline]

3 minutes ago, TheGlenlivet said:

I delidded my 7700K and applied liquid metal, but didn't lap or resurface the die in any way.  At full load on all cores it would sit in the 90s and touch 100 degrees with a corsair h110 on it at full blast.

Delidded, it now sits in the 70s and hits 80 occasionally.   This is at 4.8GHZ and 1.23 v.  I know others have gotten higher speeds and lower temps, but the delid is worth it, even if you leave it stock..

I've never delidded a Kaby Lake CPU (so I can't back this up), but I've heard that it tends to have more adhesive than Skylake.

[JoostinOnline]

Linus mentioned that they're doing another delidding video tonight on the WAN show.  I couldn't help but wonder if he read this.

[TahoeDust]

On 8/23/2017 at 10:55 AM, Tim613 said:

seems like delidding has done a great help for x299 form what i hear

11c for me.

[DildorTheDecent]

6 hours ago, JoostinOnline said:

Linus mentioned that they're doing another delidding video tonight on the WAN show.  I couldn't help but wonder if he read this.

Better not be a mess like that abomination in that original video. 

[DanielMiddletown]

I think, perhaps Linus had a bit bigger idea in mind. If a channel with so many viewers would say "Yes you should go and cut your CPU with a razor and replace the TIM and it would have great improvement on the temperature", we would have a huge amount of broken CPU-s. People are idiots(including me). Today it`s quite a different story because there are a lot of "Turn&Pop" delid tools and tutorials available. With X299, Intel should have included delid tool in the box...

[JoostinOnline]

51 minutes ago, DanielMiddletown said:

I think, perhaps Linus had a bit bigger idea in mind. If a channel with so many viewers would say "Yes you should go and cut your CPU with a razor and replace the TIM and it would have great improvement on the temperature", we would have a huge amount of broken CPU-s. People are idiots(including me). Today it`s quite a different story because there are a lot of "Turn&Pop" delid tools and tutorials available. With X299, Intel should have included delid tool in the box...

They existed a long time before Linus made that video.  I just think he wasn't very well informed.  He would have used a vice or removal tool otherwise.

[dn96]

Didn't certain Haswell chips have issues with heat because of the TIM? Especially in the case of the 4790K, still thermal throttles at stock speeds with a Noctura NH-D14. Although the idea with the adhesive does make sense somewhat

[JoostinOnline]

3 hours ago, dn96 said:

Didn't certain Haswell chips have issues with heat because of the TIM? Especially in the case of the 4790K, still thermal throttles at stock speeds with a Noctura NH-D14. Although the idea with the adhesive does make sense somewhat

It was with the extra adhesive they used on Haswell.

 

The TIM on Skylake and on Haswell is the same AFAIK.  I don't have any data to back that part up though, so I could easily be wrong.

[LinusTech]

Spoiler alert we didn't get a great result out of Skylake-X in the new video but great results from kaby

[JoostinOnline]

2 minutes ago, LinusTech said:

Spoiler alert we didn't get a great result out of Skylake-X in the new video but great results from kaby

I look forward to seeing it.

 

Btw, I know it sounds like I'm crapping all over your video, but like I said in my first post, I have an enormous amount of respect for you.

[Columbo]

21 minutes ago, LinusTech said:

Spoiler alert we didn't get a great result out of Skylake-X in the new video but great results from kaby

Mr. Tech Tips. Any dirt on the Z370 chipset/motherboards or early sightings or testing of the 8700K? 

[DanielMiddletown]

10 hours ago, LinusTech said:

Spoiler alert we didn't get a great result out of Skylake-X in the new video but great results from kaby

Hopefully my Skylake-X delid goes better...

[JoostinOnline]

 

This time Linus removed (and acknowledged) the insane amount of adhesive they used.  He also used better thermal compound, which I'm sure contributed to it some.  It resulted in a 22C drop.