Lapping guide?

[martman]

Could someone please link me to a trustworthy lapping guide? This will be my first attempt and will be lapping a new zalman 9700.

 

[ther00kie16]

CPU lapping guide. Lapping heatsink is basically the same.
You really only need like 200/400, 600/800 and 1000/1500. Anything more yields very little improvement if any. No need to get a perfect mirror finish.

 

[aigomorla]

Originally posted by: martman
Could someone please link me to a trustworthy lapping guide? This will be my first attempt and will be lapping a new zalman 9700.

is this for your FX?

i dont think you'll see any difference.

Lapping showed improvement on quadcores because of unleaven ihs.

Even C2D's of earily kind had a concave IHS.

 

[martman]

No.. I'm currently buying parts for a new system.will be for a q9550. Havent got the cpu and mobo yet, just the zalman,memory and new psu. I thought lapping the zalman(if needed) would give me something constructive to do in the meantime.

thanks for the replies



*future build*
Q9550 (mild OC hopefully)
EVGA 750i FTW
pcp&c 750 quad
4 gb muskin ram

 

[BonzaiDuck]

First-- on the sandpaper. I frankly do not see the value in using wet-or-dri graded beyond 400-grit. For the CPU IHS, I start with 240 or 320. I do this with the goal of getting the nickel-plate off the copper IHS. Once the IHS is nice and flat and only remnants of the nickel can be seen on it, I finish off with a finer grade.

However, even with 320-grit, a quarter of a piece of sandpaper will --after the initial grinding -- lose a lot of its grit, and seems more like 400 or better after you've washed the nickel and copper particles off of it.

Second, there is a value to lapping under most conditions. Nickel has a higher thermal resistance and lower thermal conductivity (two sides of the same coin) than copper -- significantly so. And if your heatsink is nickel-plated, the effort pays off double.

Some people have purportedly measured their results. These measurements depend on the thermal power under load conditions for their processor -- which, in turn, is higher than the manufacturer's rated value in proportion to the user's voltage and clock settings. The measured load temperatures -- are non-linear and exponential with voltage increases, and only rises linearly with the clock setting.

I've seen boasts by people that they reduced their load temperatures by 10C degrees for lapping both the nickel-plated heatsink-base and the processor cap or IHS. Given the fact that the system I was building at that time had thermal wattages similar to those of the posters, I was able to satisfy myself that this was, indeed, very likely. Further, I satisfied myself that simply lapping the IHS with the heatsink-base "ceteris-paribus," reduced temperatures by as much as 5C degrees.

Of course, if a processor has a TDP of around 130W, and over-clocking increases the thermal wattage by an unspecified amount -- even as high as 160 or 180W -- the benefits of lapping will show as only a couple C degrees. This is easily explained in terms of the definition of thermal resistance, which depends on the actual thermal wattage of the CPU. So even the use of top-end cooling components with the lowest thermal resistances, together with a CPU that has very high thermal wattage, will only give a marginal improvement.

 

[Quiksilver]

Originally posted by: martman
No.. I'm currently buying parts for a new system.will be for a q9550. Havent got the cpu and mobo yet, just the zalman,memory and new psu. I thought lapping the zalman(if needed) would give me something constructive to do in the meantime.

thanks for the replies



*future build*
Q9550 (mild OC hopefully)
EVGA 750i FTW
pcp&c 750 quad
4 gb muskin ram

You do know Zalman coolers perform quite poorly on quads right?

 

[Tempered81]

Originally posted by: BonzaiDuck
First-- on the sandpaper. I frankly do not see the value in using wet-or-dri graded beyond 400-grit. For the CPU IHS, I start with 240 or 320. I do this with the goal of getting the nickel-plate off the copper IHS. Once the IHS is nice and flat and only remnants of the nickel can be seen on it, I finish off with a finer grade.

However, even with 320-grit, a quarter of a piece of sandpaper will --after the initial grinding -- lose a lot of its grit, and seems more like 400 or better after you've washed the nickel and copper particles off of it.

Second, there is a value to lapping under most conditions. Nickel has a higher thermal resistance and lower thermal conductivity (two sides of the same coin) than copper -- significantly so. And if your heatsink is nickel-plated, the effort pays off double.

Some people have purportedly measured their results. These measurements depend on the thermal power under load conditions for their processor -- which, in turn, is higher than the manufacturer's rated value in proportion to the user's voltage and clock settings. The measured load temperatures -- are non-linear and exponential with voltage increases, and only rises linearly with the clock setting.

I've seen boasts by people that they reduced their load temperatures by 10C degrees for lapping both the nickel-plated heatsink-base and the processor cap or IHS. Given the fact that the system I was building at that time had thermal wattages similar to those of the posters, I was able to satisfy myself that this was, indeed, very likely. Further, I satisfied myself that simply lapping the IHS with the heatsink-base "ceteris-paribus," reduced temperatures by as much as 5C degrees.

Of course, if a processor has a TDP of around 130W, and over-clocking increases the thermal wattage by an unspecified amount -- even as high as 160 or 180W -- the benefits of lapping will show as only a couple C degrees. This is easily explained in terms of the definition of thermal resistance, which depends on the actual thermal wattage of the CPU. So even the use of top-end cooling components with the lowest thermal resistances, together with a CPU that has very high thermal wattage, will only give a marginal improvement.

10C load is probably the maximum improvement you will see - but it's worth it. More than likely lapping the IHS and HSF will give you about 4 to 6 degrees improvement on the load temps... IMO - 1 or 2 degrees minimum and 8 to 10 maximum depending on how well the connection is.

 

[Dorkenstein]

Is lapping my E8600 necessary if I want to overclock it? The idea makes me nervous, since if I damage it, I'm screwed.

 

[katank]

Yeah, if you are willing to drop cash on a q9550, you should be able to afford a TRUE or a Xigmatek HDT1283.

I recently lapped both my TRUE and Q6600, obtaining great results. I'd recommend you lap forward and backward. Don't follow the guides that tell you to lap in a circle. That tends to not produce as flat surface. Also, don't be afraid of using a drop or two of water to help w/ the lap.

 

[Tempered81]

Yah, no circles... lap until you see all copper, check flatness with razor blade in bright light. hard to get a mirror shine lapping in circles, IMO

try testing with and without TIM after lapping both surfaces.

 

[Tempered81]

Originally posted by: Dorkenstein
Is lapping my E8600 necessary if I want to overclock it? The idea makes me nervous, since if I damage it, I'm screwed.

No - you can still OC. the lapping just helps reduce temperatures by providing a more solid contact between the two copper blocks...

 

[Dorkenstein]

Oh, what I meant is, is the temperature bonus worth me potentially destroying my cpu?

 

[Tempered81]

Originally posted by: Dorkenstein
Oh, what I meant is, is the temperature bonus worth me potentially destroying my cpu?

hahah! That's the associated risk!

:laugh:

 

[Dorkenstein]

Hmm, I'll take that as a no, I guess. However, if the heatsink is already lapped is it pointless to use with a non-lapped cpu?

 

[KoolDrew]

Originally posted by: Dorkenstein
Hmm, I'll take that as a no, I guess. However, if the heatsink is already lapped is it pointless to use with a non-lapped cpu?

The benefit would be larger if both surfaces were completely flat, that's all.

 

[BonzaiDuck]

Originally posted by: jaredpace

Originally posted by: BonzaiDuck
First-- on the sandpaper. . . . .

10C load is probably the maximum improvement you will see - but it's worth it. More than likely lapping the IHS and HSF will give you about 4 to 6 degrees improvement on the load temps... IMO - 1 or 2 degrees minimum and 8 to 10 maximum depending on how well the connection is.

I'd agree to that without reservation. I think we're of one mind on this.

Originally posted by: Dorkenstein
Is lapping my E8600 necessary if I want to overclock it? The idea makes me nervous, since if I damage it, I'm screwed.

You're in luck, dude. My project this year started with an E8400 and ended with an E8600. I'm holding the E8400 as a replacement, or to use in another project. It was an earlier stepping in the Wolfdale line, and the news was too good for the E8600 first-issue of the E0 stepping.

There are at least a couple reasons I'd lap the sucker despite the warranty fears, and let me return to that matter just a little later here.

These Wolfdales are eminently over-clockable. In building a Wolfdale system, I wouldn't think of ending the project to run only at stock settings.

Here's the method I recommend for the lapping. There is a black plastic cover which comes with the retail-box LGA-775 CPUs, and it protects the gold-dot array of contacts. If you bought an OEM CPU, try and think of another way to do it, but the retail cover has small latches on all four edges for securing it to the CPU -- small plastic barbs. You can therefore use it to protect the otherwise-bare surfaces of greatest concern. [Intel along with general wisdom does not favor leaving fingerprints on the contacts.]

Use a surface of known flatness and strength, like a glass plate . . .[I have a 1/2" thick glass coffee-table surface]. Wet the sandpaper on both sides: it should adhere nicely to the glass. But dab off the excess water on the gritty side. Hold the plastic latches with your fingers -- securing the retail cover. Use a combination of circular motion and back and forth movement, trying to avoid having the CPU "bump" or stutter along the sandpaper surface -- it will do this because of the friction.

When you need to lubricate the paper some more, just use a couple of drops of water. My practice is to wet a paper towel and wring out a couple drops on the sandpaper as needed. Or you could use an eye-dropper. Run the sandpaper under the tap periodically to get rid of the nickel and copper particles.

You run very little -- if any -- risk of damaging the CPU if you just take a little care. Get a can of compressed air and blow off the surfaces of the processor after you finish, to get rid of any water droplets. You can dab the IHS surface periodically during the sanding with a dry, folded paper towel -- to absorb any excess moisture and metal particles.

On the risk-and-warranty issue, I really do not see any material risk, even if you lose the warranty options by lapping off the identifying information, nickel-plate, etc. The only way you'll damage the CPU is through over-clocking it.

An E8600 will clock easily with air-cooling to 4.0 Ghz. Some people are pushing them higher. But the real threat to the lifespan of the Wolfdale is the voltage and heat due to excessive over-clocking. Technically, that would void your warranty, but Intel might not detect that you "abused" the CPU, while in lapping it -- the resultant smooth copper surface -- is obvious and easy to catch for warranty "enforcement."

On my 780i motherboard, I've OC'd the E8600 to 4.1 to 4.15 Ghz with a CPU volt-setting of 1.30V. Then I backed off the speed setting to 4.0 Ghz using the same voltages for the higher setting.

The names of other voltages are different for different chipsets. You must contain your urge to increase the CPU_VTT or CPU_FSB voltage to below an actual result of 1.40V. Mine is currently set at 1.30, and I believe the sensor reading is equal to or very close to the "set" value. The 1.30V setting for the CPU is an insignificant increase over the "retail-box" maximum warranty limit of 1.25V for the Wolfdale, and in my case, it generates a sensor-reading of 1.28V at idle, and between 1.25 and 1.26V at load.

The Wolfdales -- many of them -- arrive in the retail box with defective TJunction core-temperature sensors, and Intel formally argues that the sensors were not meant to measure idle temperatures, while there is some evidence that the sensors function normally under load conditions once the temperature reaches the "stuck" value that appears at idle temperatures. So good cooling (and a colleague above has made valid criticism of the Zalman -- nevertheless sufficient) -- and lapping -- is extra "insurance" since evaluating thermal wattage and temperature using these core values is not entirely confidence-inspiring if only for the reported defect and Intel's disclaimer.

If you have monitoring software that can read the TCase sensor in addition to or instead of the TJunction core temperatures, use it to evaluate temperature at below-load settings. The TJunction temperatures will always be higher than the TCase -- from 1C to 10C greater (more specific data on the Wolfdale is available at the Intel site, but the 65nm Conroe predecessor to the Wolfdale showed a difference of about 10C according to Intel.)

I use a Noctua-NH-U12P heatpipe-tower, facilitated with a 120x38mm Panaflo exhaust fan and a 120x25mm stock Noctua fan or any other fan of the same size that is rated above about 0.15 amps @ 12V. Even the stock Intel cooler-fan is sufficient with the Noctua or a similar heatpipe cooler, if you can find a way to secure it to the cooler, and provided that an exhaust fan is situated to work as a "puller" fan to assure good air-flow.

It appears that I have too much time on my hands. I have a reputation here in the forums for "writing a book when a few sentences would do.

Good luck.

 

[Dorkenstein]

Great post, thanks! Should I buy one of the lapping kits I see online? Also, I don't have the plastic cover for the cpu anymore. Can't really think of any other way to cover it reliably.

 

[Tempered81]

Here's a fella lapping a socket 775 chip:
http://www.youtube.com/watch?v...6EDD3F6443769A&index=0

It is a two part home video of a guy lapping his IHS.

speed ahead to about 7:55 in the 2nd video. Notice what the cpu surface looks like


Here is a guy lapping his Thermalright ultra 120:
http://www.youtube.com/watch?v...xnoDwk&feature=related

 

[BonzaiDuck]

Originally posted by: jaredpace
Here's a fella lapping a socket 775 chip:
http://www.youtube.com/watch?v...6EDD3F6443769A&index=0

It is a two part home video of a guy lapping his IHS.

speed ahead to about 7:55 in the 2nd video. Notice what the cpu surface looks like


Here is a guy lapping his Thermalright ultra 120:
http://www.youtube.com/watch?v...xnoDwk&feature=related

I don't know if it makes much difference to count your "swipes" in different directions, as shown in that first video. I just try to keep the paper flat (the video shows use of tape, which I recommend, but I don't bother with it), and I casually switch between back-and-forth motions occasionally flipping the chip around 90-degrees, and a circular motion.

What I also do is to keep a small metal straight-edge handy, and stop every now and then to hold the chip up to a light source and see if there are any gaps between the straight-edge and the processor cap -- applying the straight-edge in different orientations of the compass across the center of the IHS.

Dorkenstein:

I'm sure there are kits available for lapping. I just happen to be an occasional wood-worker and case-modder who keeps a supply and assortment of wet-or-dri sandpaper in my shop. You can, of course, buy the stuff in various sizes at your local AutoZone, Kragan or other auto-parts supply chain -- and any hardware store carries the sandpaper in vast quantities and selections.

I can't give a precise answer to the question "What if I bought an OEM CPU, or lost the little plastic cap?" Surely, I probably lapped at least two processors without attempting to protect the gold-dot array. Just be a little more careful handling the CPU. Use a latex glove to hold it, and grasp only the edge of the CPU's little square circuit-card.

 

[Idontcare]

Originally posted by: BonzaiDuck
What I also do is to keep a small metal straight-edge handy, and stop every now and then to hold the chip up to a light source and see if there are any gaps between the straight-edge and the processor cap -- applying the straight-edge in different orientations of the compass across the center of the IHS.

Hi BonzaiDuck, been a while since our last engagement. Hope all is well with you since we last conversed.

An alternate approach that I started doing for determining if my IHS/HSF surface was still concave/convex was to take a sharpie (permanent ink pen) and make an asterisk pattern on the surface.

Then do a few swipes (2-3 or as many as 10) on the sand paper and inspect, anywhere the IHS/HSF surface was not contacting the surface of the sandpaper will still have a notable amount of the original sharpie marking on it. Visual maps out the entire topology of convex/concave areas at once.

Here is an example - starting picture of my Tuniq HSF with a blue asterisk on it...and a picture after some 10 swipes on 400grit paper showing the obvious off-center concave area.

Later on I did another flatness check - starting picture again...and a picture after some 10 swipes on 400 grit showing nearly 100% of the blue is gone from all areas.

A relatively "flat" HSF is now ready for some 800 grit love

Originally posted by: Dorkenstein
Great post, thanks! Should I buy one of the lapping kits I see online? Also, I don't have the plastic cover for the cpu anymore. Can't really think of any other way to cover it reliably.

Go to autozone or any pep-boys, etc auto parts place. They carry 8.5x11 inch sheets of all the varying grits you need. I am speaking from experience here, do NOT get those prepackaged lapping kits on the internet unless the sandpaper they provide is in fact full 8.5x11 sheets.

Here is a direct comparison of what you get from autozone versus those internet shops: http://i272.photobucket.com/al...cket/Bang_for_Buck.jpg

What I got from SVC was these dinky little 3x4 inch pieces of sandpaper that meant your sanding time was 5x what it would otherwise be on a much less expensive but same quality sandpaper from autozone or other.

I bought two "lapping kits" from two different internet places and they both shipped me these postage stamp sized useless pieces of sandpaper. You could move your chip maybe 2 inches back and forth. It felt like prom night all over again. Save yourself the money and frustration, buy the largest sandpaper you can find and cut it down to size if you need to.

As for "protection"...that plastic cap invariably ends up sliding back and forth a little while you are lapping and in my view that was likely to do more damage to those CPU contacts than me just touching the the things with my bare (yet cleaned) hands. I lapped some 6 quads doing that...no plastic cap, no hand protection, plastic means static charge can accumulate, you are almost always better off not putting plastic in contact with your CPU if motion/friction is going to be involved. The only thing you are protecting your CPU from is your hands, so clean them up beforehand and away you go.

And don't worry about getting your CPU wet during the process, just make dam sure it is dry before you put it back into the socket. I wet sanded and dry sanded my quads. In all cases I liberally doused them with water to remove sanding remnants between successive grits. When I was all done lapping I submerged them in a bowl filled with 90% IPA and then shook them dry. Left them to further air dry overnight before installing. Had zero issues with all six quads doing this technique.

 

[BonzaiDuck]

Originally posted by: Idontcare

Originally posted by: BonzaiDuck
What I also do is to keep a small metal straight-edge handy, and stop every now and then to hold the chip up to a light source and see if there are any gaps between the straight-edge and the processor cap -- applying the straight-edge in different orientations of the compass across the center of the IHS.

Hi BonzaiDuck, been a while since our last engagement. Hope all is well with you since we last conversed.

An alternate approach that I started doing for determining if my IHS/HSF surface was still concave/convex was to take a sharpie (permanent ink pen) and make an asterisk pattern on the surface.

Then do a few swipes (2-3 or as many as 10) on the sand paper and inspect, anywhere the IHS/HSF surface was not contacting the surface of the sandpaper will still have a notable amount of the original sharpie marking on it. Visual maps out the entire topology of convex/concave areas at once.

Here is an example - starting picture of my Tuniq HSF with a blue asterisk on it...and a picture after some 10 swipes on 400grit paper showing the obvious off-center concave area.

Later on I did another flatness check - starting picture again...and a picture after some 10 swipes on 400 grit showing nearly 100% of the blue is gone from all areas.

A relatively "flat" HSF is now ready for some 800 grit love

Originally posted by: Dorkenstein
Great post, thanks! Should I buy one of the lapping kits I see online? Also, I don't have the plastic cover for the cpu anymore. Can't really think of any other way to cover it reliably.

Go to autozone or any pep-boys, etc auto parts place. They carry 8.5x11 inch sheets of all the varying grits you need. I am speaking from experience here, do NOT get those prepackaged lapping kits on the internet unless the sandpaper they provide is in fact full 8.5x11 sheets.

Here is a direct comparison of what you get from autozone versus those internet shops: http://i272.photobucket.com/al...cket/Bang_for_Buck.jpg

What I got from SVC was these dinky little 3x4 inch pieces of sandpaper that meant your sanding time was 5x what it would otherwise be on a much less expensive but same quality sandpaper from autozone or other.

I bought two "lapping kits" from two different internet places and they both shipped me these postage stamp sized useless pieces of sandpaper. You could move your chip maybe 2 inches back and forth. It felt like prom night all over again. Save yourself the money and frustration, buy the largest sandpaper you can find and cut it down to size if you need to.

As for "protection"...that plastic cap invariably ends up sliding back and forth a little while you are lapping and in my view that was likely to do more damage to those CPU contacts than me just touching the the things with my bare (yet cleaned) hands. I lapped some 6 quads doing that...no plastic cap, no hand protection, plastic means static charge can accumulate, you are almost always better off not putting plastic in contact with your CPU if motion/friction is going to be involved. The only thing you are protecting your CPU from is your hands, so clean them up beforehand and away you go.

And don't worry about getting your CPU wet during the process, just make dam sure it is dry before you put it back into the socket. I wet sanded and dry sanded my quads. In all cases I liberally doused them with water to remove sanding remnants between successive grits. When I was all done lapping I submerged them in a bowl filled with 90% IPA and then shook them dry. Left them to further air dry overnight before installing. Had zero issues with all six quads doing this technique.

Generally, I agree to everything VL says here, but if I grab the plastic cover around the latches to hold it secure to the CPU, I don't need worry about my fingers coming in contact with the gold-dot array.

The Sharpie-pen trick is also a good idea, but if you plan to grind off all the nickel plating to bare copper, you would wait to implement Idontcare's idea at that stage. It may be true that some IHS's are more uneven or warped than common sense would dictate, but it seemed to me that you would be getting the surface pretty flat if you persevere in grinding down to bare copper.

 

[martman]

I have just 1 question about lapping a HS as big as a Zalman 9700...Do I try to handle the entire unit while sanding or just remove the bottom contact plate from the HS? (It appears to be removeable)