Caution 3870x2 and Maybe 4870x2? Rare HEATSINK problem hopefully

[gOtVoltage]

Ok after several weeks of my temps on core two slowly going up on a stock 3870x2 i found that the heat sink was seperating..

I know for fact the 4870x2 uses two simalar copper sinks like the 3870x2 . The studs that are factory pressed into the Sink slowly pulled out of the COPPER on my 3870x2.. Before this happened My max temps were around 80c on a hot day with stock clocks and many bench runs for both cores crossfire enabled.


The cause of all this,,

The spring pressure and retaining bracket put too much preshure on the Copper Sink and combined with normal temps the copper would expand a litlle and walla the studs eventually came loose...this makes the heatsink pull away from the GPU causing the Higher temps! The Aluminum sink does not seem to be affected ,, its the rear CopperHeatsink @the DVI connector end of VideoCard.

I did not tear down the whole card but it seems the Aluminun sink did its job propperly...Seems the COPPER may be too heavy for the Card since it is always suspended under it when mounted .. Cards that face up may not ever see this problem. For the rest of us i would check those HEATSINKS for any sign that its not even with the Main memory/PCI 1.1 heatsink.. They should be flush and even all the way around...

The card still works but @ 112c on one Core(stock)and 65c max on the second under 3Dmark06 caused me to look into this..


Something i never would of expected ... Hmmm this really has me thinking,,4870x2's will be using TWO copper sinks instead of just one

This was way too high for a single Core 118c max temp on core with 22c ambiant room condition! even 843mhz ,,To test this i set the faulty Core to @18mhz more than stock..Screen shot was right after the Bench run.



Here is what to look for with out total disasembly (DVI end of card)



Notice the Hole in the heatsink on the right side, the Stud has dropped down where it no longer sticks above the hole. 2 out of the four studs slipped down and they are only pressed in (not threaded into the sinks)from what a tech had told me when i called





Also the Back spring and tension bracket may lift on the coners where studs have come out of sink....




NOTE:

POWER PLAY TEMP protection started tripping the card eventually ..Then i decided to bench it to see what i could find.
Id check this out if any of you have abnormal temps . I was using RivaTuner to set the Fan to 100% all the time and i figured i must have a bad driver tripping powerplay....I Knew it wasnt the driver when i threw in my back up 3870/ddr4 and it ran Flawless Oced @810core/ 70c max..

This can happen with any 3870x2 or even 4870x2 since it uses the same Heatsink technology...Im hoping the 4870x2 is not affected"knock on wood"

[xMrBunglex]

the 4870 X2 doesn't have the same heatsink. the 4K cards run a lot hotter than the 3K cards and have much bigger heatsinks.

[gOtVoltage]

the 4870 X2 doesn't have the same heatsink. the 4K cards run a lot hotter than the 3K cards and have much bigger heatsinks.

Here we go ... See those nice Red circles those are press in pins .. they failed on my copper sink as it expands under load...

Since the 4870x2 Runs even hotter they did some changes and i hope the Studs which are the Same (Circled in red) dont come loose!...

The main differance is 1 MORE COPPER Heatsink and a added heatpipe connecting the two together ( 3870x2 copperheatsink is about twice is heavy..)The 4870x2 are lighter but can still poes a problem on a card that mounts down..With Heat and how ever good the new ones are pressed in we will only know once there out...












Can you tell the differance besides color and a few minor heatsink changes..?

With the exception that there is not a PLXheatsink in the center the base and Copperheatsink's still mount the EXACT SAME WAY.

Red one is 3870x2 and the Black is 4870x2.. i really hope im wrong with what ive found to be a flaw in the COPPER HEATSINK....

I too am buying a 4870x2 and just got a big eye opener.. Now a water block sounds real good ATM.. But some people who choose a Referance design might encounter what i just CSI'ed

For the most part id say with 4870x2 it should be fine. The Copper sinks are a lighter (copper base with solderd fins)(studs are still only pressed in)

P.S.
I am in no way trying to stir things up... I am just telling the facts from what ive found.


Thanxs for reading,

gOtVolTage

[gOtVoltage]

Ok ,, so what i had this little problem with the heatsink...Im glad i did too..

Know whats real funny i lost the reciet too .. Instead of sending it back or explaining reciets i decided to see what i could do...

So i used a centerpunch and punched the copper into the studs from the side to keep the studs tight ..(three little punch dots per stud)then i added MX-2 to the GPU's only and keept everything stock including the Volts..

Im more than pleased with my temps now

[dannyboy321]

nice work some good information here keep it up nothing wrong with finding a problem and fixing it yourself still not many people have this skill to do so it better be fixed in the 4870x2