To lap or not to lap?.

Sgt Tackleberry · 4 May 2011 at 17:19

Hi guy's and girl's,

This weekend I will be putting my i5 760 back under water again.
When I had it under water a few weeks ago temps was 30'c idle and 50'c fully load.
I've been thinking of lapping my cpu to see if I can shave more off my temps.
But Is it really worth it or not?.
What harm could I do to my cpu?.

Thanks

Phase · 4 May 2011 at 17:34

If you have a lapping machine or you have 5 hours spare I would say yes.

If you dont want to spend hours on it dont bother.

Sgt Tackleberry · 4 May 2011 at 17:44

It really take 5hrs?, from what I have been reading it takes 30mins tops.

Jokester · 4 May 2011 at 17:46

Just check that your block is making good contact, if it is, it's not worth lapping.

JohnTedd · 4 May 2011 at 17:47

I can't offer you anything definitive, but I decided to lap my old Intel Core 2 Extreme CPU when re-building my PC. I did the lapping by hand and the downside is that I managed to sand the skin off my finger, so it was quite painful. The resulting PC does run cooler, but whether that is down to the lapping or better TIM I used I couldn't say.

Sgt Tackleberry · 4 May 2011 at 17:54

Thanks guy for the input.
I think I mite give it a miss then.

Thank you.

buttkinz · 5 May 2011 at 15:13

like jokester said, if its totally flat dont bother, my phenom looked reasonably flat but was anything but lol, i dropped nearly 10 degrees from lapping so its worth having a good check if your temps are a little high.

WingZero30 · 5 May 2011 at 17:21

Sgt Tackleberry said:
Thanks guy for the input.
I think I mite give it a miss then.

Thank you.

OP you should give it a go. I just ordered various grit sand papers and will be lapping both my Thermalright IFX-14 and Q6600 as the contact pattern is like an 'I pattern, so doesn't cover the whole cpu IHS.

buttkinz said:
like jokester said, if its totally flat dont bother, my phenom looked reasonably flat but was anything but lol, i dropped nearly 10 degrees from lapping so its worth having a good check if your temps are a little high.

This is something I would love to see aswell in my case when I proceed with lapping

zoomee · 5 May 2011 at 20:05

The Q6600's were worth lapping (I lapped mine!) as they have a concave (or is it the opposite lol) Heatspreader

Hell in the olden days I even removed the IHS from my FX-53 (for a whopping 100Mhz gain lol ) and killed it months later placing waterblocks straight onto the core lol

Best thing to do is hold a stanley blade against your CPU - if you can see its pretty much level I wouldn't bother. Pointless lapping a waterblock as it's more than likely already level quite well

Just think re-sale value for the sake of a couple of megahurtz

Phase · 5 May 2011 at 20:15

Like i said you need to get it like this

This might only give you 5c and few mhz if your lucky.

I have lapped poss 3 CPUs Socket A 3200 (2525GhZ) That was on chilled water and a Q and this i7.

Use your time to fine tune the ram you will get about the same improvement

game4it · 5 May 2011 at 20:45

I found it can be worth it to gain a few c's depending on how uneven the cpu was in the first place.
I drew a grid of few lines on the cpu and tried a very quick lapping with a very high grit wet'n'dry just to see if cpu was uneven.If the lines are worn evenly after that quick lap i dont bother going the whole with lapping.

Scon · 5 May 2011 at 20:50

Get your voltages down a bit! 1.35v is an insane amount for 4ghz, try 1.3v mine only needs 1.27v for 4Ghz, but needs 1.38 for 4.3Ghz.

WingZero30 · 5 May 2011 at 21:10

zoomee said:
The Q6600's were worth lapping (I lapped mine!) as they have a concave (or is it the opposite lol) Heatspreader

Hell in the olden days I even removed the IHS from my FX-53 (for a whopping 100Mhz gain lol ) and killed it months later placing waterblocks straight onto the core lol

Best thing to do is hold a stanley blade against your CPU - if you can see its pretty much level I wouldn't bother. Pointless lapping a waterblock as it's more than likely already level quite well

Just think re-sale value for the sake of a couple of megahurtz

LMAO!!

How did you manage to take off the IHS on FX-53?

The other method is to place the blade on CPU IHS near a light source (could be anything such as bulbs, tubes or even sunlight) and see if light is penetrating through the interface between blade edge and CPU IHS. If it is then you know it is lapping time.

If no light is penetrating through, then the heatsink base or CPU IHS are flat enough :cool:

.

zoomee · 5 May 2011 at 21:35

WingZero30 said:
LMAO!!

How did you manage to take off the IHS on FX-53?

The other method is to place the blade on CPU IHS near a light source (could be anything such as bulbs, tubes or even sunlight) and see if light is penetrating through the interface between blade edge and CPU IHS. If it is then you know it is lapping time.

If no light is penetrating through, then the heatsink base or CPU IHS are flat enough.

- I used to be a nutter in them days - £600 FX-53 2.4Ghz - overclocked to only an extra 100Mhz under water, so I went extreme and removed the IHS using a shaving blade (them old school ones your pops used to use) - got an extra whopping 50Mhz out of it LOL - taught me a lesson.

Luckily the CPU only died when the Dual core ones were released (4400+ for like half the price!) - due to me chipping off an edge of the core - It used to run for 15minutes then freeze up. It was defo the CPU :eek:

- My gud ol wavemaster case modded to heck! (clickable thumbs)

I kept it as a reminder of how foolish I used to be (spending soo much on a darn CPU! lol) - Kids chuck it around the house these days lol.

w3bbo · 5 May 2011 at 21:54

Phase said:
Like i said you need to get it like this
This might only give you 5c and few mhz if your lucky.

I have lapped poss 3 CPUs Socket A 3200 (2525GhZ) That was on chilled water and a Q and this i7.

Use your time to fine tune the ram you will get about the same improvement

I'll call your shiny and raise my mirror finish

In all honesty though the idea of lapping is not to get it this shiny. It's to get it flat. The Nehalem cpu's had especially concave IHS and temp drops of upto 10c could be seen on really bad examples. My e6600 dropped 7c iirc and I got an 8c drop on my Q6600. I lapped my bloomfield and it made 1c of difference so not really worth it.

You only really need to go upto 800 grit though. You won't get a shiny finish on the cpu but as long as it's flat, the next few grades of paper will make little/no difference on temps.

setter · 5 May 2011 at 21:59

I managed a drop of 11c on my old q6600, albeit my TRUE was lapped as well. Wasnt mirror finished but nice and flat. This allowed me to clock that cpu to 3.8ghz. Wouldnt consider it on my current i7 though.

WingZero30 · 5 May 2011 at 22:01

w3bbo

Did you check afterwards if your lapping produced straight flat surface on Q6600?

w3bbo · 5 May 2011 at 22:03

WingZero30 said:
w3bbo

Did you check afterwards if your lapping produced straight flat surface on Q6600?

Aye used graph paper.

Phase · 6 May 2011 at 00:52

w3bbo said:
I'll call your shiny and raise my mirror finish

In all honesty though the idea of lapping is not to get it this shiny. It's to get it flat. The Nehalem cpu's had especially concave IHS and temp drops of upto 10c could be seen on really bad examples. My e6600 dropped 7c iirc and I got an 8c drop on my Q6600. I lapped my bloomfield and it made 1c of difference so not really worth it.

You only really need to go upto 800 grit though. You won't get a shiny finish on the cpu but as long as it's flat, the next few grades of paper will make little/no difference on temps.

I see your mirror and .... Na lol .

That shines like a shiny thing thats very shiny.

V F · 6 May 2011 at 01:22

All this shine reminds me of chrome plated zippo lighters.