Question on lapping HS and grit..

[ch33zw1z]

I'm planning on lapping a 7700CU to cool a E6600. I've seen a few guides that say 600 grit is fine to stop at. Other guides climb up to 2000...my question is whether or not anyone has seen significant drops in temp after 600 grit. Maybe I didn't search for the right keyword..

 

[Idontcare]

Depends on the objective. Lapping is done to make the surface flat with respect to the mobo and the HSF.

Polishing is done to make the surface smooth and reflective.

Having a mirror-smooth IHS which is badly angled from one side of the chip to other side is about as worthless as having never lapped or polished in the first place. (lay a mirror down on a table, then lift up on one side, the mirror is still smooth and flat but not with respect to the table anymore)

So first order of business is to ensure you have a flat surface and that it is flat with respect to the geometric plane of the motherboard and the geometric plane of the bottom of the HSF. This can be done with 400 grit.

The choice to go higher than 400grit is mostly to decrease the likelihood of having scratches running so deep that the TIM cannot get all the way down inside and instead will entrap air. Entrapped air is the problem.

So if you intend to just make your IHS/HSF "flat" and stop at 400 grit or 600 grit then I recommend you "tint" the surfaces with your thermal past before proceeding to add thermal paste and assemble the CPU+HSF.

Tinting is the process where you put a little thermal paste on the IHS or HSF and then using a coffee filter or a plastic bag you rub the thermal paste into the scratches really well. The surface will become "tinted" as the scratches are filled with the thermal paste.

Once tinted, proceed as if you had polished the IHS with 2000 grit. I.e. add your dollop (or line if quad CPU) to the middle of the IHS and put the HSF on.

Tinting is not something special or new, in fact it is Artic Silver's recommend procedure for using there Ceramique thermal paste. I do it with AS5, and just about everything else I use. How could it hurt?

 

[The-Noid]

I start with 220 then 400, then 1000, then 2000.

Most important is to tape the sand paper to the glass/mirror whatever and you will have a cpu that ends up with quite a bit more shine.

 

[ch33zw1z]

Thanks for the replies. I have a flat surface to do it on, which is a glass desktop. I have 600 and 1000 grit sandpaper. It will take me a couple days to complete, will post results!

 

[sgrinavi]

Originally posted by: ch33zw1z
Thanks for the replies. I have a flat surface to do it on, which is a glass desktop. I have 600 and 1000 grit sandpaper. It will take me a couple days to complete, will post results!

It may take longer than that if you start with 600... also, I noticed in your first post that you were going to lap the cooler, you need to lap the CPU as well or the benefit will be greatly diminished.

When I did my q6600 I found that my Tuniq Tower was actually much closer to flat than the cpu....

 

[BonzaiDuck]

I've acquired a collection of 1000 to 2000-grit wet-or-dry sandpapers for my case-mod painting-and-finishing projects.

I do not believe that using anything more than 600-grit for either the heatsink base or the IHS processor cap offers any benefit. I usually start with 400 and finish with 600.

Why do you want to waste your time with a Zalman 7700 "copper flower?" That model and the earlier, smaller version, had thermal resistances between 0.16 and 0.22 C/W. The newer heatpipe coolers are pushing thermal resistances down to 0.09 C/W.

 

[ch33zw1z]

Originally posted by: BonzaiDuck
Why do you want to waste your time with a Zalman 7700 "copper flower?" That model and the earlier, smaller version, had thermal resistances between 0.16 and 0.22 C/W. The newer heatpipe coolers are pushing thermal resistances down to 0.09 C/W.

Boredom, but if it doesn't fit on the Asus P5k that's headed my way then I'll be picking up a 9500 AT, is that the cooler you're refering too?

Just for the record, the 7700 has definitely given me great temps for long enough to be worth the money..but I never mind an upgrade

 

[The-Noid]

9700CU is the newest Zalman.

If you are going to spend the money I would recommend a Tuniq Tower or Thermalright Ultra 120 Extreme.

 

[ch33zw1z]

Originally posted by: Yoxxy
9700CU is the newest Zalman.

If you are going to spend the money I would recommend a Tuniq Tower or Thermalright Ultra 120 Extreme.

What are they're +'s and -'s over the 9500? 9700?

 

[aigomorla]

Originally posted by: Yoxxy
9700CU is the newest Zalman.

If you are going to spend the money I would recommend a Tuniq Tower or Thermalright Ultra 120 Extreme.

Listen to Yoxxy. This is also my recomendation.

Trust me, there are very few people on this forum who knows quads better then he does. :X

 

[ch33zw1z]

Originally posted by: aigomorla

Originally posted by: Yoxxy
9700CU is the newest Zalman.

If you are going to spend the money I would recommend a Tuniq Tower or Thermalright Ultra 120 Extreme.

Listen to Yoxxy. This is also my recomendation.

Trust me, there are very few people on this forum who knows quads better then he does. :X

Good to know for when I acquire a quad! Dunno if either of those towering HS's will fit in my LianLi PC60..

 

[aigomorla]

Originally posted by: ch33zw1z

Originally posted by: aigomorla

Originally posted by: Yoxxy
9700CU is the newest Zalman.

If you are going to spend the money I would recommend a Tuniq Tower or Thermalright Ultra 120 Extreme.

Listen to Yoxxy. This is also my recomendation.

Trust me, there are very few people on this forum who knows quads better then he does. :X

Good to know for when I acquire a quad! Dunno if either of those towering HS's will fit in my LianLi PC60..

missread the E for a Q. lol...

Ummm, your next best choices would be a scythe mini, or a SI-128. :X

Should of asked what case you had. Rear 80mm fan means not a lot of clearance.

 

[ch33zw1z]

Well the 7700 fits on the P5K, so I won't be picking up a new one yet. But I will be working on the 7700 to get the most out of it.

 

[aigomorla]

Originally posted by: ch33zw1z
Well the 7700 fits on the P5K, so I won't be picking up a new one yet. But I will be working on the 7700 to get the most out of it.

2 ways to increase sink efficency without moding it.

1. Increase the heatload on the sink area [dont think you want to do this tho]
2. Reduce your ambient temps [might be what you should do]


Try to get better vents in and out of your case, and you'll increase your sinks efficency. If its already at its max free flowing, then:

1. you need to lap the base of the sink if its not flat, or lap the IHS. [both void warrenty]

And if that still wont make you happy:

Listen to us and get a new sink. :T

 

[ch33zw1z]

Originally posted by: aigomorla

Originally posted by: ch33zw1z
Well the 7700 fits on the P5K, so I won't be picking up a new one yet. But I will be working on the 7700 to get the most out of it.

2 ways to increase sink efficency without moding it.

1. Increase the heatload on the sink area [dont think you want to do this tho]
2. Reduce your ambient temps [might be what you should do]


Try to get better vents in and out of your case, and you'll increase your sinks efficency. If its already at its max free flowing, then:

1. you need to lap the base of the sink if its not flat, or lap the IHS. [both void warrenty]

And if that still wont make you happy:

Listen to us and get a new sink. :T

might just. I like the looks the the ThermalRight that was recommended. just need to measure! The last Thermalright product I used was SI-97? Was happy with it..may be time to go back...we will see

 

[The-Noid]

PC60 fits both of these heatsinks.

I would rather just throw a little more goop on the IHS than to lap the heatsink. You are looking at best case scenario of 5 degrees between the two.

First, buy a new heatsink. If temperatures still arn't great. Put a little bit more TIM on than you usually would as this will fill in the convex heatsink.
Finally, if this doesn't work think about lapping then.

 

[ch33zw1z]

Originally posted by: Yoxxy
PC60 fits both of these heatsinks.

I would rather just throw a little more goop on the IHS than to lap the heatsink. You are looking at best case scenario of 5 degrees between the two.

First, buy a new heatsink. If temperatures still arn't great. Put a little bit more TIM on than you usually would as this will fill in the convex heatsink.
Finally, if this doesn't work think about lapping then.

I was actually incorrect, I have a PC65...as far as I know the dimensions are the same. You have any info?

 

[The-Noid]

Should still fit no problem.

 

[BlueAcolyte]

Oops...

 

[ch33zw1z]

Originally posted by: Yoxxy
Should still fit no problem.

Thanks, I got a big ole 120mm silent fan that would go great with it...may just do it, it's tough to spend that kind of money when this 7700 does the job for now.

 

[aigomorla]

Originally posted by: Yoxxy
Should still fit no problem.

yoxxy u sure about this?

last time i heard only cases which have a 120mm exhaust could fit sinks these large.

The pc65 has a 80mm rear fan no?

Best thing to do is messure the depth from your CPU IHS to the top of the case before you buy. A lot of companies wont take sinks back once u used them.

 

[The-Noid]

I ran one in my pc60 I got from frozenpc.

 

[BonzaiDuck]

Originally posted by: ch33zw1z

Originally posted by: BonzaiDuck
Why do you want to waste your time with a Zalman 7700 "copper flower?" That model and the earlier, smaller version, had thermal resistances between 0.16 and 0.22 C/W. The newer heatpipe coolers are pushing thermal resistances down to 0.09 C/W.

Boredom, but if it doesn't fit on the Asus P5k that's headed my way then I'll be picking up a 9500 AT, is that the cooler you're refering too?

Just for the record, the 7700 has definitely given me great temps for long enough to be worth the money..but I never mind an upgrade

ch33zw1z -- it depends on your over-clocking ambitions. For the number of posts on these forums you've racked up, you should drop in to the discussions at Cases and Cooling more often. Also, check the Anandtech comparison reviews for May and August, '07. Even if ThermalRight (or even Sunbeam Tuniq) costs more, any of even the most recent Zalmans are comparitively a waste of money.

Originally posted by: Yoxxy
9700CU is the newest Zalman.

If you are going to spend the money I would recommend a Tuniq Tower or Thermalright Ultra 120 Extreme.

Ditto. For what it's worth, I'll migrate from a TR HR-03-Plus VGA cooler to the Zalman VF-1000 as I need to for a build-in-progress, but unless I see reviews that suggest lower thermal resistances for some new cooler out there, the U-120-Extreme, Ultima-90 and Tuniq are about as good as it gets. Anyone has information to the contrary -- please inform me. It's difficult to stay on top of that market all the time.