dissapointed with sk6!

[sendatooli]

i finally went and got two sk6's for my two cpu's. i should have done this a lot earlier. or should i have? yesterday in haste i got some "comp-usa" heatsinks. nothing special, junk actually. they were running my cpu's at 38c. idle. 44 full load. my alpha pep66 was badly damaged(long story) so it was running them at over 50c, no good.

heres the kicker: the sk6's i got today have the same EXACT performance as the cheapo comp-usa heatsinks. to reiterate, 38c. idle 44c. full load. i'm using a 25cfm orion fan on this. i like it because its quiet.

well, i know exactly what the problem with these heatsinks is! they need a good lappin'. it is really a shame that a top of the line heatsink like these comes with machine marks all over it. add to that pits and valleys. it feals like 50 grit sandpaper when you run your hand over the bottom. it makes very poor contact with the cpu. i recently even read somewhere that the sk6's lately have been appearing with lousy machining. that is sad that they dont make this product better. seeing as it costs 3 times what a regular heatsink that will do the job does.

anyways, dont buy this unless you plan to carefully lap it.

this is just my experience. ymmv.



sendatooli.

[RangerJoe34]

re-set the heatsinks, maybe they dont have a good connection ,and the fans are not very powerful that might alway be the prob. and maybe your temp probe is broken, are you using a built in probe?

[SickBoy]

Yeah, there are some QC issues with the later batches of SK6's. I hope Thermalright addresses this issue. I lapped mine enough so that the core contact area is flat (the HSF still isn't totally flat). Keep in mind also that you're not using a terribly high performing fan with it - 25 CFM is a bit on the low side.

Mine works well though.

If you know of a halt-on-idle tweak for your motherboard, that will lower your idle temps considerably. I have noticed that the CPU idle percentages are around 60% on a lot of newer DDR boards. I don't like this. My WPCREDIT-hacked KT7A idles my TBird at 1 or 2 percent. Such a tweak makes your cooling look a lot better.

[fuzzba11]

Originally posted by sendatooli

heres the kicker: the sk6's i got today have the same EXACT performance as the cheapo comp-usa heatsinks. to reiterate, 38c. idle 44c. full load. i'm using a 25cfm orion fan on this. i like it because its quiet.

sendatooli.

The heatsinks with smaller fins are meant for high CFM fans...if you want a quieter HSF you should have gone for a silverado or something that was meant to have a low CFM.

[Jon]

Glaciator is one of the best performing quite running air coolers out there...probably would've been more up your alley.

I couldn't be happier with my SK-6, but I am running it with a Delta too.

[nikhsub1]

I dont want to sound like a broken record, the SK6 was designed to run with the 38 cfm delta. You can get an 80 mm fan to put on there, you don't need an adapter, just turn the fan 45 degrees and use the stock clips. I would get like a 43-50 cfm 80mm - will be fairly quiet.

[William]

depending on the comp usa you refer to, it could be affecting the sensor temps which isn't uncommon for some temps. I would try a lappin, that will probably yield a very good drop in temps.

[sendatooli]

thanks for the replies guys. i wish i had known the sk6 was for a more powerfull fan! i guess ill try a 8cm fan on it. i would really prefer not to lap it. it is so "chunky" that i will have to remove a lot of metal to get it flat. i dont have the tools to get it even!
so i was wondering in this case would i be better off using the "gelvet" (thermal pad?) it came with. instead of the artic silver? i'd rather not waste the gelvet if it will give me worse performance. never know what i will need it for.



thank you,
sendatooli.

[Wega!]

AS2 is much better than the thermal pad. Also AS2 takes some time before it works best, so you won't get the best performance if the AS2 is recently applied.

[*JEREMY*]

If the machining marks are as bad as you say then you are going to have to just take the time to lap it,just start out with rough sandpaper and work your way up depending on how bad it is.Otherwise whats the since of even having it,right?Just an expensive piece of copper.Mine wasnt that bad but it did require a lapping.I have also heard that if the surface is fairly poor that it can leave indentions in the die of the chip.

[sendatooli]

hah, it did leave an indentation on the chips! and the bottom of the heatsinks say amd! does that mean its making good contact and doesnt need to be lapped?
ok, how do i lap it to make sure i dont get a slope or uneven surface? with only sandpaper or a file? i killed my alpha trying to cut off the feet and lap it with a file.
i already used 1500 grit on the sk6's. all it did was scratch it up and dull the copper finish.
would someone tell me exactly how to do this? or point me to a guide on the web?

also, i just installed the delta 38cfm screamers. now i remember why i cant stand these things! it is now running at 34c. idle and 39c. full load. none of my voltages are increased. they actually run low. lousy psu. so do these numbers sound right with the delta, or is it not making proper contact? besides lapping it how can i get under 40 full load with a real quiet fan? i already have an air duct installed over the fan to outside the case. to bring in fresh air instead of recirculate the hot case air.

i really, really dont want to reck these sk6's!

i also noticed on the front page of this site in the heatsink reviews. that the numbers they got werent far off from mine. my cpu's probably put out more wattage when o/c'd then the ones they tested. is that all i can expect from the sk6's with 25 cfm fans?


thank you,
sendatooli.

[nikhsub1]

Yes those temps with the delta are great! No lapping required! Remember you do not lap to make the surface "smooth", you lap so the bottom of the heatsink is not concave. Scratches and stuff do not really affect cooling properties as long as it is "flat". Using 25 cfm fans will result in bad temps. You can use a quieter 80mm fan with around 45-50 cfm. No adapter needed, just rotate fan 45 degrees.

[oc jason]

i venture to say that eh Glaciator is THE BEST all around HS out today. I mean 29cfm fan at 36db, and i have it correctly installed and lapped, at 38c load with my signature system. That is pretty good for no intake air. I dont like the sk6, as it allows 50c idle temps on my buddys 1400. But correct placement (contact) and lappin + As2 will never fail you in my opinion, and yes get a better fan.

O O, i just remembered my friend turned the fan around the blow down onthe HS instead of sucking away form and dropped 5c, maybe try that?

[lennytiger]

I had thesk6 for a short time and found that even with the delta it dodn't work on my 1.4 Server, it was a 55C Full load with as2 the bad machining on mine was bad my 1.4@1.6 got hot!! Then I put a global win cak38 on at 7V and it was at 47C Full Load!!!

[sendatooli]

well this sucks. i bought two of these. two cpu's. i guess the temps with the delta are ok. but it doesnt cut it with a 25cfm fan. also, i cant seem to fit the 80mm. on there by rotating them. not enough room. darn. i cant beleive i wasted my money on these. everyone i previously talked to said they were the best. the thing is i dont have room for big hsf's. so these probably have to do.


sendatooli.

[lennytiger]

If the full load temp is below or a little bit more than 50C it should be fine if they aren't oc/ed!

[sendatooli]

they are o/c'd. with the 150 fsb they run 49c. under load. i thought it was crashing on 150 fsb because of my psu or memory. but it doesnt get unstable untill it hits about 46c.
at 138 fsb, they work fine at 44c. full load.

i just need som instructions on how to lap them. anywhere on the web with a guide?
i cant return them, and i am surely not buying two others now!
i wish i had known this before i bought them.

what i'm wondering is why did the machine crash imediatly with the delta 38cfm installed? with the 25cfm orion it runs about an hour or so. did the delta suck all the power out of the psu? it's hard to beleive it uses that much power. i have much bigger fans in there than the delta.

also, how do i fit the 80mm. fan on the sk6's? the clip doesnt bend that far on mine even with the fans at 45 degree angles. use the biger clips?


thank you,
sendatooli.

[sendatooli]

i just checked out the glacieater. they will not fit on my mobo. they are huge! plus in the front page article of this site it says the sk6's are better. even with a low rpm fan. so how come we are all getting different results? my system seems to be crashing at high fsb because of heat. 48c. full load at 150fsb. but, my ambient temp is pretty high too. lot of stuff in my case plus hot room. i just dont know why i cant use the delta 38cfm for now. if i plug it in the machine crashes straight away. it sucks all the juice i guess.


sendatooli.

[Sonny]

You can try lapping the SK6s if they are really uneven then try powering your fans with a seperate PSU. I think the real problem is that with really high ambient temps you just can not expect to get cooler temps. Hot air can not cool a hot HSF.

[mw521]

Originally posted by sendatooli
they are o/c'd. with the 150 fsb they run 49c. under load. i thought it was crashing on 150 fsb because of my psu or memory. but it doesnt get unstable untill it hits about 46c.
at 138 fsb, they work fine at 44c. full load.

i just need som instructions on how to lap them. anywhere on the web with a guide?
i cant return them, and i am surely not buying two others now!
i wish i had known this before i bought them.

what i'm wondering is why did the machine crash imediatly with the delta 38cfm installed? with the 25cfm orion it runs about an hour or so. did the delta suck all the power out of the psu? it's hard to beleive it uses that much power. i have much bigger fans in there than the delta.

also, how do i fit the 80mm. fan on the sk6's? the clip doesnt bend that far on mine even with the fans at 45 degree angles. use the biger clips?


thank you,
sendatooli. If you send them to me I will lap them for you. (mebbe a six pack in return?):D

[sendatooli]

i brought my heatsinks to my friends machine shop. they have all computerized hi-tech stuff there. so he used a laser machine and told me it is as flat as i could hope for with soft copper. almost perfectly flat. anyways he did say that it has a lot of ripple in the finish. not great machining. he said it is more important that it is not concave than the fact that is rippled. also, he said if i am getting under 40c. max load with the delta it is making good contact. so he told me he would not die cut it. if i want to lap it he told me to use sandpaper, but then he said it may no longer be flat. since sandpaper is not hi-tech stuff! so i guess its more important that its flat (which it almost is), then the fact that the finsih has machining marks. it feals rough when i run my hand over it. but, my friend said that is what the artic silver is for. even though it feals rough, i guess those ridges are only a few microns thick. so he told me if i want i should rub it with 1500 grit sandpaper. but he said not to go cutting into it with 400 grit. i think i will listen to him, as i just ruined 2 alphas this way.



>>>>>i wanted to add i just attached 80mm. fans to the sk6's (bent the clips so bad theres no going back to 60mm.!) they are 36 cfm. and they do not run any cooler than my 25cfm fans! i guess this is because they are only 36cfm and the hubs are bigger. plus air "spills" over the sides since the fans are bigger than the heatsink.
what cfm. 80mm. fans do i need to get down to a lower temp then the alpha 38cfm. 60mm. and still be quiet? if this exists.

i can make 142 all fast settings, or 146 medium. but no 150. maybe its not cooling. (see my power supply and memory settings post). i think i should stay under 40c. full load, right?

thank you,
sendatooli.