Sign in with
Sign up | Sign in
Your question

How much of an effect can lapping a HS and/or IHS have?

Last response: in CPUs
Share
a b à CPUs
May 26, 2007 9:32:45 AM

Just wondering what kind of effect on temps lapping the surfaces of the HS and/or IHS can have. My dads e6600 loads under orthos at around 55C and its at 2.7Ghz and stock vcore (about the same temps as stock). He is using AS5 and an Asus Silent Knight cpu cooler. He has a gigabyte 3D aurora case with an added 80mm fan on the side panel (perspex) and the front fan filter removed. It might be his last way to lower temps.

More about : effect lapping ihs

a b à CPUs
May 26, 2007 9:43:07 AM

Yea but this thing is kinda a zalman 9500 copy, so it should do better, heres a pic:

http://www.hardware.info/images/news/silent_knight07_55...

I would think it would do better than the stock cooler (which it doesnt)

EDIT: Some people get like high 30's, although granted with like a tuniq tower.
a b à CPUs
May 26, 2007 9:57:22 AM

If only it were possible to laser cut both surface so they were flat even at microscopic levels, allowing the complete removal of thermal paste altogether and therefore the removal of 2 material transitions. I think I might see how much of an effect on temps I get by removing thermal paste from my 3700 and just sticking on the HS clean. Be funny if temps dropped although they already idle in the low 20's (celcius). I can get my 3700 down to 18C when at 1.8ghz @1.1V with full fan speed, and thats at or below ambient AFAIK (I know, its impossible, but ever heard of wind chill factor?).
Related resources
a b à CPUs
May 26, 2007 10:11:45 AM

Surely it wont burn out that fast, it will still have mediocre contact with the cpu. When attempting to install the silent knight on my dads e6600, we didnt seat it properly the first time and in the BIOS we hit 80C+. We took it off and only one edge of the thermal paste (we had covered the whole IHS surface that time and later put it on properly) had actually spread out at all. So there was probably around 10% contact.
May 26, 2007 10:12:27 AM

There was a guy on here about a year ago from CSIRO that did an ion fusion process between the ihs and the HS... It did a bit better than AS5, but not by so much that I'd be willing to have my CPU permanently bonded to my HS...

Wusy used to swear that he could get 3 to 5 degrees C difference by lapping, but he was GOOD! Mirror finish to mirror finish... Shouldn't even need thermal compound for what he turned out. If you have an old cpu that you don't care about, practice...

My 2p
a b à CPUs
May 26, 2007 10:14:55 AM

The only old cpu I have is in my brothers pc. Its an athlon t-bird 800mhz with no IHS. Think I should lap it? :lol: 
May 26, 2007 10:23:27 AM

Uh... Who wields the best cricket bat? And who can stay awake the longest? Probably not a good idea, but if you ask politely and he agrees...

Nah. Not going there. Go to your local repair shop and get a handful of dead p4's to practice on. Bet they have a few...
a b à CPUs
May 26, 2007 10:34:07 AM

Wait, I DO have an old pentium MMX 200mhz here somewhere that I was gonna make into a keyring... about a year ago :p  Just got no mobo to test it with.

Time to find some 1000 grit sandpaper.
May 26, 2007 10:37:43 AM

Isn't that CPU in one of those cast packages? ie, no metal IHS?
a b à CPUs
May 27, 2007 2:11:14 AM

Um I dunno, but it looks like its got an IHS. Btw, how thick is the IHS on most modern cpus? Like how far could you lap without hitting the cpu itself?
May 27, 2007 4:25:37 AM

You just want to even out the hills/valleys. 1000grit sounds too coarse to me. I'd start with 2000grit. The hard part is ending up with an overall flat surface, not just a locally smooth surface that has dips and rises on a cm scale.
a b à CPUs
May 27, 2007 4:34:37 AM

2000 grit eh? Well looks like I'll be heading to Bunnings warehouse soon.
a b à CPUs
May 27, 2007 5:37:50 AM

Thanks, what kind of polishing compound, like brasso or something?
May 27, 2007 5:53:02 AM

I was thinking of an automotive-type polishing compound, but now that I think of it, a compound designed for polishing brass should work OK on copper.
May 27, 2007 6:01:33 AM

Around 1-3c from reviews I have read. Although I haven't done this myself.
May 27, 2007 7:07:52 AM

Lapping is great. I used to do the hsf for my xp chips (not the chips though) and would often cut 7 to 10 c off the top temp.
Unfortunetly, you are talking about a conroe. The IHS is very concave on those boys. It gets to the scarey part before you see any dif.
On the other hand, your temps do seem a little high. You may have an airigation (airflow) problem. Try taking the side panel off, and see what happens.
A lot of cases have too many fans sucking air out, so they end up doing little or nothing. It's good to balance the intake and exhaust fans.
a b à CPUs
May 27, 2007 7:23:39 AM

Yep the 3D aurora has that vacuum problem, but even with the side panel off, it gets to these temps. If its concave, that would explain the fairly poor contact then right?
a b à CPUs
May 27, 2007 8:49:26 AM

Ok um, how does that at all apply to this thread?
a b à CPUs
May 27, 2007 8:57:48 AM

And we all have the money for peltiers :lol: 
a b à CPUs
May 27, 2007 10:03:50 AM

But how good are those cheap ones for a cpu?
May 27, 2007 11:25:47 AM

lapping can decrease your temps by 5c. but thats only my video card anyway.
i used 80grit first, for about 2 mins then 150grit for 3 then i used 600grit for 4mins. i reapplied the zalman thermal paste that came with my 9700led and temps are idling at 37c and 42-43 before.
a b à CPUs
May 27, 2007 1:33:19 PM

side comment first. Wind chill factor, ie FEELS like 50 below applies to living beings. Velocity and h20 content will affect rate of cooling, But will not lower the temperature below ambient - more likely if reading is below ambient the reading is in error.

Good discussion on lapping and airflow. Just read an article on temps inside of cases. Used thermo imaging. One point was that the front fan blows the air across the hard drives which raises the air temp which reach the CPU. Tried it (revearsed the air flow on the front fan - OPPS negative air pressure. Need to retry with compensating air flow increase from the side.

My 6400 @ 3.2 is hotter than I like, 55 - 57 (TaT reading with Othoes) I may have put too much thermo paste on.
May 27, 2007 2:42:36 PM

Quote:
Yea but this thing is kinda a zalman 9500 copy, so it should do better, heres a pic:

http://www.hardware.info/images/news/silent_knight07_55...

I would think it would do better than the stock cooler (which it doesnt)

EDIT: Some people get like high 30's, although granted with like a tuniq tower.


I'm getting 46c under load using a stock cooler. Your choice of mobo could have an impact on the temps you're getting. Also make sure you've a decent power supply for that setup. A quality 500 watt supply will make a difference. Using a lower quality power supply with limited output will stress system components and cause overheating and over time, failure.
May 27, 2007 7:44:55 PM

Read this thread and got a little curious too, so i decided to give it a try on my old comp. I put this thing together with all the parts i had lying around
and replaced building my current rig.
It's a p4 3.2 Ghz stock cooler asus p4p800 and has a thermaltake case( but-ugly what was i thinking :oops:  ) with 3 fans, front sidepanel and back.
Monitored temps with speedfan and everest for comparison wich showed identical temps. Ran two instances of Prime95, one Blend and one In-place for heat, and this is what came out.

Before lapping temps: idle 34* C
Dual prime95 52* C

Then i lapped the heatsink and CPU using the finest waterproof sandpaper i have, first dry then wet (yes i live a little dangerously 8O ) untill i ended up with an almost shiny surface. There were still a few very tiny scratches visible but nothing serious. Then i put the thing back together without using thermal paste so metal to metal and fired it up just for kicks :twisted: Again this what came out.

After lapping, no paste: idle 37* C
Dual prime95 58* C

So a little warmer but nothing i'd worry about, not bad right?
Then i ripped it apart again and applied what must be the thinnest layer of thermal compound i've ever seen (basically seethrough) and stuck it back in. Here's the results.

After lapping, little paste: idle 33* C
Dual prime95 49*C

Basically a 3 degree profit for half an hour of work, not half bad if you ask me. I'm sure if you'd spend a little more time perfecting the finish there's more to be had here, but for me it was just a little fun project on a rainy day. 8)
a b à CPUs
May 28, 2007 4:26:44 AM

Quote:
I'm getting 46c under load using a stock cooler. Your choice of mobo could have an impact on the temps you're getting. Also make sure you've a decent power supply for that setup. A quality 500 watt supply will make a difference. Using a lower quality power supply with limited output will stress system components and cause overheating and over time, failure.

Ok maybe I should list the specs of my dads system:

ab9 pro
e6600 with asus silent knight
TT toughpower 750W
x800gto
gigabyte 3d aurora with front fan filter removed and added 80mm side panel fan
May 28, 2007 1:53:26 PM

Quote:

Ok maybe I should list the specs of my dads system:

ab9 pro
e6600 with asus silent knight
TT toughpower 750W
x800gto
gigabyte 3d aurora with front fan filter removed and added 80mm side panel fan

Which variant of the 3d aurora - one with a mesh side or one with a window? I have heard that the window ones really suck for cooling, and a single side fan might not overcome that.
May 28, 2007 2:37:00 PM

I also have a 3d aurora case. The biggest thing i say about that case is REPLACE THE STOCK FANS. They are total JUNK. Very quiet fans but push almost no CFM for a high heat output system. And take off that 80mm on the side and screw on a 120mm. That is what i did. I purchased 4 TT fans all with around 72+cfm. Replaced all the stock fans removed front fan filter, then dremeled out the metal grill behind the front fan, then ran some benchies. I was running almost 8c lower on idle can not remember load. And when you stuck your hand in the case you could actually feel air being moved through the case. Then i mounted the 120mm in the center of the mesh on the side that way it gave cool air to the NB, CPU, and some to video cards.

Edit: Spelling
May 28, 2007 6:42:34 PM

Should I lap my CPU and HSF? At load with the sock cooler, my E6600 (running at stock) was reaching 83oC after a few hours. with my Artic Cool 7 Pro at load it's running 68oC at max.
May 28, 2007 7:14:34 PM

gd70: assuming your case has decent ventilation, your temps suggest a problem with the mounting of the Freezer 7 Pro. Unfortunately, Intel's 4-pin mechanism is notoriously easy to not-quite-properly install. This post may help: http://forumz.tomshardware.com/hardware/modules.php?nam...
(step 2.5 onwards)
May 28, 2007 8:05:18 PM

Quote:
gd70: assuming your case has decent ventilation, your temps suggest a problem with the mounting of the Freezer 7 Pro. Unfortunately, Intel's 4-pin mechanism is notoriously easy to not-quite-properly install. This post may help: http://forumz.tomshardware.com/hardware/modules.php?nam...
(step 2.5 onwards)


The door is open on the side and the PS, and a fan at the back are pulling out. I Have reinstalled the heatsink numerous times, making sure that I put just enough compound and locking the 4-pin evenly and correctly, the last two times I had the mobo out of the case so I could closely check the pins from the front and back of the board. (this was the same thing I went through with the stock heat sink.)
May 28, 2007 8:36:59 PM

Have you connected the fan on the CPU directly to the PSU, or told BIOS to run the fan at full speed all the time if you plugged it into the Mobo? Check to see if everything else in your case is getting hot too. Those temperatures are WAY too high for an E6600 at stock speed. I hope you didn't damage the CPU by letting it get to 83C with the stock cooler (which is also too high for a stock speed CPU). By the way, how are you measuring the CPU temperature?
May 28, 2007 10:13:44 PM

Quote:
Have you connected the fan on the CPU directly to the PSU, or told BIOS to run the fan at full speed all the time if you plugged it into the Mobo?


Set the fan to run between 90-100% at lower temps, so it's rare for the fan to run below it's peek on my system.

Quote:

Check to see if everything else in your case is getting hot too. Those temperatures are WAY too high for an E6600 at stock speed.


The general temps (I'm guessing the case temps) are running at 35oC at highest.

Quote:

I hope you didn't damage the CPU by letting it get to 83C with the stock cooler (which is also too high for a stock speed CPU).


Down clocked the possessor until I got my 7 Pro to keep the temps sub 75oC

Quote:

By the way, how are you measuring the CPU temperature?


Core temp, Rightmark CPU clock Utility, and there was another (only trial and I don't have the original install program) which all show the same exact temps, But speed fan is showing exactly 15oC cooler compared to all the other programs, load or idle (Is this the 15oC offset I've been hearing about?) TAT won't run at all, just install (Error enumerating On Demand Clock Modulation Support).
a b à CPUs
May 29, 2007 5:40:36 AM

Quote:
Which variant of the 3d aurora - one with a mesh side or one with a window? I have heard that the window ones really suck for cooling, and a single side fan might not overcome that.

Perspex side panel, with a horribly cut hole for the fan.

@Fate0N3: I know they do suck, almost no air seems to come from out the back. It is probably resulting from a vacuum inside the case as well, but yes, the stock fans are low CFM (but nice and quiet) fans.
May 31, 2007 4:08:23 AM

Quote:
Which variant of the 3d aurora - one with a mesh side or one with a window? I have heard that the window ones really suck for cooling, and a single side fan might not overcome that.

Perspex side panel, with a horribly cut hole for the fan.

@Fate0N3: I know they do suck, almost no air seems to come from out the back. It is probably resulting from a vacuum inside the case as well, but yes, the stock fans are low CFM (but nice and quiet) fans.
Well if I had this problem, I'd try the following before lapping the HS & CPU:
See if I could find a mesh side panel for the case, that would allow decent ventilation. My friend has the 3D Aurora 570 with the mesh side, and it keeps his AMD 6000+ cool, so it could certainly handle an E6600. Failing the mesh panel:
. Replace crappy rear exhaust fans.
. Use 120mm instead of 80mm side fan, or add a second 80 mm.
. Maybe cut a hole in the side and duct it to the CPU fan (let the CPU fan pull the air in).
. Also, maybe check to see if the thermal compound being used is decent and properly applied - thin to win.

It just "feels" to me like the problem is inadequate cool air getting to the CPU heatsink rather than the CPU heatsink not working. Here's why I think this: I had a Lian-Li case for my old P4 designed sort of like the 3D Aurora - 1 intake fan largely blocked by the HD cage, and two exhaust fans (plus the PSU exhaust fan). The CPU and video card always ran hot (hot even for a P4) with the case side closed, and ran beautifully with the case open, and everything inside the case was hot when the side was closed, leading me to conclude the problem was inadequate airflow. I found it took two 80mm side intake fans in that case to keep it happy, but with them in there it actually ran better with the side closed than open. (The hole for the first one was horribly cut, then I actually figured out what I was doing on the second one). That was also when I swore I would never use an 80mm fan again, as the 120mm fans are so much quieter while moving large volumes of air.
a b à CPUs
May 31, 2007 5:11:58 AM

We dont have a dremel so cutting the holes in the perspex is difficult and crude, we use a drill to make lots of holes in a circular(ish) pattern and then knock out the piece of perspex. I dont know how easy it will be to drill a second hole in for an 80mm fan, so maybe we should remove one back 120mm fan and stick it on the side to replace the 80mm fan already there. That would even out the airflow quite a bit as we are decreasing exhaust and increasing intake. Should we remove the top or bottom fan, keeping in mind that the bottom is directly in line with the cpu fan which blows out towards the back like the zalman 9x00?
June 1, 2007 5:47:24 AM

Quote:
We dont have a dremel so cutting the holes in the perspex is difficult and crude, we use a drill to make lots of holes in a circular(ish) pattern and then knock out the piece of perspex. I dont know how easy it will be to drill a second hole in for an 80mm fan, so maybe we should remove one back 120mm fan and stick it on the side to replace the 80mm fan already there. That would even out the airflow quite a bit as we are decreasing exhaust and increasing intake. Should we remove the top or bottom fan, keeping in mind that the bottom is directly in line with the cpu fan which blows out towards the back like the zalman 9x00?

I know the technique you used way too well - a guy I went to college with cut a 6" piece of 1/4" thick copper out that way one time. Took him another 4 hours sanding the edges to clean up the mess the drill holes made.
Maybe try a hole saw for cutting out for fans - you know those round bladed things that go on a drill? I don't know how to explain them better, but you can get them at a home improvement store like Home Depot (or whatever the Aussie equivalent is). Oh, yeah, wikipedia shows one. Just make sure to use some sort of scrap wooden board behind the plexiglass (perspex) to help the hole cut more easily if you use one. I did my first hole with a dremel and it was awful, but the second one with the hole saw worked nicely.

I'd try removing the top fan if you need to steal one, even if the CPU cooler is blowing right at the bottom one, that's still where most of the heat is getting removed. But as I recall the back fans are easy to remove on that case, maybe try each one individually to see what kind of results you get. Hope you can solve your problem, good luck.
a b à CPUs
June 1, 2007 5:58:36 AM

Ah yes, I know those things. I dont think we have any, but we can get one.
!