one core temp way higher than others

andybird123 · 7 Dec 2012 at 13:23

lapping one or the other will still give you a benefit over no lapping at all, use a razor blade to check the flatness of the cooler - it's probably quite flat already - most waterblocks are already lapped to a high degree

doyll · 7 Dec 2012 at 13:29

elliotuk said:
I've been thinking- if I lap the CPU do I have to lap the HSF? it's a corsair H80 so would be a pain in the ass to lap as its all connected to the radiator etc. I'm not sure if it's slightly concave? if so I guess it would have to be lapped too, if it's designed perfectly flat then I
guess only lapping the CPU would be ok?

I wouldn't. It will void your warranty.

Nickolp1974 · 7 Dec 2012 at 13:33

picture of my lapped 3770, lapped on my glass hifi stand!!

stage 1

stage 2

doyll · 7 Dec 2012 at 13:34

The center was low.

Nickolp1974 · 7 Dec 2012 at 13:35

elliotuk said:
I tried lapping a cpu last year and failed, after like 6 hours of sanding it down
thanks for all advice anyway

after 6 hours was there anything left????

mine took 10-15 mins

Nickolp1974 · 7 Dec 2012 at 13:37

doyll said:
The center was low.

yep, and definately improved core spread temps for me, down to about 4c between cores at load, was 9c

doyll · 7 Dec 2012 at 14:37

Great result!
Love it when a plan comes together.

randal · 7 Dec 2012 at 14:43

Have you tried rotating the Corsair block 180 degrees to see if the problem follows the orientation of the cooler?

Sorry if this sounds daft, or impossible. Going by memory of the H50 mounts which would allow multiple positions of the block.

Also, have you tried the stock HSF? Same sort of results with that?

elliotuk · 7 Dec 2012 at 16:56

i dont have the stock cooler as i bought the cpu as OEM, but i might see if i can rotate the cooler later good idea.

With the lapping i spent hours working my way down from 400 grit all the way to 2000 grit to get a really high polish, was proper shiny! dunno how you could get such a finish in 10-15 mins :O

setter · 7 Dec 2012 at 17:01

Ive got the opposite on my 3570k, one core sits a lot lower than the rest. Sometimes it's pretty much in line with the rest. But often reads down as low as 12c. Which isnt possible on my cooling.

elliotuk · 7 Dec 2012 at 17:43

setter said:
Ive got the opposite on my 3570k, one core sits a lot lower than the rest. Sometimes it's pretty much in line with the rest. But often reads down as low as 12c. Which isnt possible on my cooling.

nice temps, what cooling you using for that?

setter · 7 Dec 2012 at 17:44

An Alpenfohn k2 cooler.

http://www.overclockers.co.uk/showproduct.php?prodid=HS-020-AL

NoobCannon · 7 Dec 2012 at 20:07

mine is the same tbh, massive difference in core temps never really worried about it

i5 3570k @ 4.7ghz

setter · 7 Dec 2012 at 20:38

I remember stuck sensors being common on 45nm s775 quads. My q9550 had this, but its not something i remember reading anything about with the 1366 i7 900 series. Both my 920 and 930 were fine. It seems to have cropped up again in this generation.

doyll · 7 Dec 2012 at 21:10

My 920 is fine but my 980 has one core (1st core) that is always about 7c low. Usually below ambient. Either it's defective or I need to patten it.