Alpha 8045 worse than hedgehog, 8045 need to be lapped?

[Freejack2]

*Background information*
Finally got my Alpha 8045 and went to install it last night. Put on my Arctic Silver II and got ready to put that bad boy in.
I noticed on the bottom it's not very lapped I can actually feel the ridges on the copper with my finger.
My cpu is easily capable of 2000+ (1667 mhz) speeds but it has to keep under about 50celsius to run stable.
I had my Kanie Hedgehog running the cpu at 1800+ speeds (1533) with temps at only 43celsius. The hedgehog only had a 30cfm fan on it.
The 8045 has a 48cfm fan on it. (Both are blowing onto the heatsink). I have the cpu running at normal 1700+ (1466) speeds and it's at 48c/118f. If I try to overclock it with the 8045 it gets too hot and crashes.
Sound like I need to lap the 8045 or did I get a dud heatsink?


*Important Question Here*
If I need to lap it. What grit sandpapers do I need?
Thanks.

 

[SpeedTester]

You sure you installed everything correctly? Did you happen to use the 4 extra washers to increase the spring
pressure? Sometimes that might help. Also make sure the heatsink isnt touching any other component on
the board. I lapped mine to a mirror finish and the temps went down 3-4c, my fan is also bloing down.

 

[Freejack2]

Haven't tried the 4 extra washers. Is it normal for the copper base to have grooves in it I can feel?
The hedgehog may not be shiny but there are no grooves that I can feel...

 

[oakfan]

I believe the 8045 is designed to have the fan sucking instead of blowing. I seem to remember a recent thread where someone changed from blow to suck (very dubious phrasing here) and the temp dropped by several degrees.

Hope this helps

 

[Freejack2]

Thanks have to try that too. Also going to go to home depot tonight and get some sandpaper.

 

[SpeedTester]

Mine had small grooves on the copper part before I lapped it. Not sure about the others here.
My temp actually went up 2c when I had the fan sucking.

 

[Freejack2]

For some reason your myrig link doesn't work.
Question for you, what cpu are you using, and what temps are you getting?
Thanks.

 

[SpeedTester]

<< For some reason your myrig link doesn't work. >>


I keep forgetting to fix that.




<< Question for you, what cpu are you using, and what temps are you getting? >>


T-bird 1.2 @ 1.522
1.775v
38-41c
49 max load with cpuburn running for 6 hours
3x 80mm in fans
4 x 40 Drive coolers in
3x 80mm out fans
1x 92mm out fan

48cfm fan on pal8045

 

[Freejack2]

I think I found my problem and I'm not so sure how or if this can be fixed. I'm not even sure of the cause. But for some reason it appears that one side is higher than the other.
I noticed that on the top side the heatsink was further away from the base screw thingys than the bottom side (which was touching them). I put the heatsink on a flat surface and it appears the heatsink isn't bent or anything. I remounted it so it was as flat as possible (heatsink was equally a small bit from touching the base screw thingys on both sides) It helped some, also set the fan to blow instead of suck. About the best it does is get within 3 to 4 degrees of the hedgehog. Oh yeah I'm using the flat washers to mount the base for the 8045, flanged ones are too big for holes.
I played around for the past few hours with the alpha 8045 and the hedgehog trying different speeds and voltages. Every test the hedgehog beat out the alpha by 3-4celsius.
I'm thinking more and more the 8045 I got is a defective one.
Sound like I should get an RMA or am I doing something wrong?

 

[Insidious]

I don't know what MoBo you are on, but I remember a thread from some time back

where a guy on a KT7-Raid (I think) had some minor interference from his RAM socket

which held his 8045 up slightly. check for this. I went ahead and installed my 8045

with no lapping (I saw the machining marks on mine also) and it has been great.

 

[TurboJason]

So, any other people sand down their alpha? I just got mine and my cpu won't be here for a couple of days? What sandpaper should I use?

Thanks in advance,
Jason

 

[SpeedTester]

Hey there Jason,

I lapped mine with the following sandpapers.

600-----800---1200----1500---2000

I used a piece of glass from my work, I wet the sandpaper with a little water and dishsoap.

 

[The_Lurker]

Also, when lapping, take your time i did a rushed lap job on a crap heatsink i was playing around with, and it lowered the temps pretty good, and it looked flat, but it wasn't mirror finish and had grooves. Key word is patience (which i dont have, lol ) G'luck!

 

[EdipisReks]

actually, for best performance, lap the heatsink until it is flat but don't give it a mirror finish. when it is a mirror the heatsink compound can't work effectively, but when it is flat but slightly rough the compound can efficiently transfer heat from the cpu to the heatsink.

--jacob

 

[Grendel99]

I heard somewhere that if you lap it too much, that you will create micro-grooves and very tiny divites that the thermal compound can't get into and therefor your temps will become higher or about the same. I think it said that you should use up to 1500 grit, but nothing higher? Anyone else remember this?

 

[Freejack2]

I did the 400-600-800-1000-1500-mothers polish to lap mine.
No change whatsoever.
What a waste of time.

 

[grdh20]

RMA

 

[MoFunk]

So should the fan be set to suck or blow? Boy that sounds funny.

 

[cnhoff]

I think those Alphas pretty much have a mirror finish, at least mine has. Also temps are way better than with my old 6035. I am using a 26cfm fan sucking and getting 48C max at full Seti load with my TBird@1520@1.75V.

Imho your 8045 is damaged,return it!

 

[fishbonez]

The last 3 Alpha's I received all had mirror finish. If yours is grooved, RMA. Lapping is way over rated IMO. Good way to kill time if you have nothing better to do.

Edipisreks, I disagree with you. A mirror finish is less efficient? I don't think so. Thermal compound is meant to fill small pores and groves where no contact with the CPU can be made. While it is obviously more efficient than air, it's not as efficient as direct HS/CPU contact. Essentially, the less thermal compound, the better (higher direct contact ratio).

 

[DoubleL]

You can't get a heatsink to flat and it is always better to have the fan blow over your heatsink, Just my 2 cents