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Help! 8RDA+ and Thermalright SLK-800 and Hot?

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Drinyth

Registered
Joined
Jun 24, 2003
Location
Twin Cities
Hi All. I just registered and am relatively new to overclocking (although I have a lot of computer experience - just mostly at "retail" levels). In any case, I'm experiencing somewhat poor performance from my 8RDA+ and Thermalright SLK-800 and was hoping that you folks would be able to help. My setup is the following:

- Chieftec "Dragon" case w/ 4 case fans - two intake near the lower front and two exhaust in the back.
- AMD 2700+ Thouroughbred-B
- Epox 8RDA+ w/ Vantec Iceburq active cooling on Northbridge and passive heatsink on Southbridge
- Thermalright SLK-800(a) with generic 80x80x20 30 cfm case fan (I think that's what the fan is from what I can tell).

Currently, I'm running at 11.5x200 (2300 MHz). I'm reading my temperatures from MBM5 and my temperatures have been as follows:

CPU: 45 idle / 51 load
Case: 30 idle and load

I was running at 12x200 for a while, but under load, the CPU temperature started climbing to 56-57 and I got nervous so backed down my settings a bit even though Prime95 hadn't spit out any errors.

I just got the HSF today and have tried remounting it already with little change in its effectiveness. I was careful to clean the heatsink and CPU core with acetone and rubbing alcohol before placing a thin layer of thermal grease. I am using the generic thermal grease that came with the Thermalright SLK-800(a) although I may get some AC3 tomorrow if people think it will really help?

With the retail AMD HSF, I was getting temperatures of around 53 under load at 11x200. Was I expecting too much from my new HSF? At 11.5x200, I am running 2 degrees cooler than previously, but I'd still like to be able to push my system harder as it seems that the CPU will take it. I've seen other folks on here with the same HSF and that are getting temperatures of high 30s idle and low 40s under load and I'm wondering what I'm doing wrong? :(

Any suggestions on things I might want to try? I'll buy some AC3 if people really think that will help, but I'm a little skeptical that it will give me the drop in temperature that I'm looking for. Should I try remounting everything again? My case temperature isn't that hot at 30 degrees and with 4 case fans, that would seem to be plenty of airflow? Can anyone think of anything else? I'm wondering why my CPU temperatures are 7-8 degrees higher than those other people that are posting here?

Thanks for your help!
 
Two things that will help drop your temps...a Tt2 fan and AS3...the Tt2 fan will drop it much better then a 30CFM fan and you can control the RPM's if you don't like the noise...or if you don't really care about noise...a 92mm fan works great...but is very loud...adding AS3 will also help lower your temps another 3-5c (after a 72+ hour burn in)...on top of the Tt2's performance...going with either a Tt2 or Tornado fan and AS3 will get you pretty much where you are wanting in temps...

Also, Welcome to the Forum...
 
Sorry for my n00bness, but what's Tt2? :D I'd do a search on the forums, but I can only do a minimum of four characters.

My voltage is at 1.725 currently. Right now, with just a bunch of browser windows open and a few putty windows, I'm at 46 degrees. Seems hot to me considering what it's doing (or not doing). When it was approaching 56-57 at load, I had the CPU voltage at 1.8. I backed off a little bit after seeing though temps though.

I just posted this and already got two responses (which I appreciate very much!). I'm going to pick up some AC3 tomorrow, I guess. I'll take a look at getting a higher CFM fan as well (I was hoping to avoid my computer sounding like a jet, but I suppose that's the price I have to pay if I want those temps). Also, I've been reading on the forums a little bit more and have found that I should switch my fan from sucking up through my SLK-800 to blowing down into my HS. All the retail fans I've had have had air coming off the processor, so I just configured this new HSF to match that.

Thanks again for all the responses and help! And if anyone has any more ideas or comments, I'd love to hear them!
 
thermaltake smart fan 2

Drinyth said:
I'll take a look at getting a higher CFM fan as well (I was hoping to avoid my computer sounding like a jet, but I suppose that's the price I have to pay if I want those temps). Also, I've been reading on the forums a little bit more and have found that I should switch my fan from sucking up through my SLK-800 to blowing down into my HS. All the retail fans I've had have had air coming off the processor, so I just configured this new HSF to match that.

The Tt2 fan has a RPM adjuster so you can keep it quite when not needing the extra cooling...and to be honest, the Tt2 fans are not all that loud for a 75.8 CFM fan...and if you have your fan set up to suck and not blow right now...turn it around..bet you will see a good 3-5c drop just by doing that...and the key thing is too keep the HS as cool as possible to get the best temps...when sucking and not blowing it does not cool the fins off but rather eliminates the heat rasing from the HS...with it blowing, it will keep the HS fins cool with dispenses heat better...
 
The smart fan 2 should do great for your temps. I get great temps with mine: 46C max on full load (XP 2100+@ 13.5*170/1.86VCore). It's not even that loud at full speed. You can also look into your case temps and see if you can have better airflow within your case (temps not too much above your room temp). The Smart Fan 2 should do it for you, though. Oh, and I hear that the temp sensor on that board is not very accurate.
 
Hrm. I turned the fan around and it really didn't change my temperatures that much. Still right around 51-53 under Prime95 load.

I'll give the AC3 a try and see if I can't pick up a Smart Fan 2 tomorrow sometime. There aren't many specialty computer shops in the area, so I may have to wait to mail order one and see how that goes.

I heard too that the temp sensor on the board wasn't very accurate, but I couldn't get a clear answer on whether the sensor over estimated the temperature or under estimated the temperature? I'll do more searching about that tomorrow on the forums.

Thanks again for all the responses. It's good to hear that my numbers aren't that out of whack considering my setup.
 
You could always do the touch test...just make sure you don't touch anything expect the HS...put your finger on the HS and see if it feels hot...running at 50+c it will definetly be hot to touch...
 
Ok.

I just tried the touch test. MBM5 is telling my my CPU is 51 degrees, but the HS doesn't feel that hot. It feels more warm than hot. I can set my finger on the HS and it doesn't feel at all like they're even close to getting burnt, so I guess that's a good thing? It actually seems the air coming out of the PS is hotter than the temp of the HS if that's any comparison. I don't have any more sophisticated temperature sensing gear though, so don't have any way of getting a more specific measurement.

If my CPU were really at 51 degrees, would the HS be very hot to the touch that I wouldn't want to touch it for very long?
 
51° C is about 124° F. Sounds right for a warm heatsink. You can always put a thermometer against it. Remember, the core will be hotter than the sink.
 
I picked up some AC3 and a Thermaltake Smart Fan II this morning. I'll install both tonight and let you folks know how it goes.
 
Also, I remember from yesterday that the bottom of my HS was not really very smooth. I didn't think much of it until reading on these forums that the surface should be very smooth. Seems that I may have gotten one of the more poorly machined SLK-800s.

The bottom of my SLK-800 has lines going lengthwise that you can feel with your finger. It's appearance can be described as ribbed or courderoy like? Anyway, I think I'll pick up some 400 and 600 grit wet/dry sandpaper and lap it a bit and see if that helps (it should also get rid of the old thermal grease in preparation for the AC3).

Man... OCing is turning out to be a lot of work. :D
 
If you feel ridges and lines you will definitely benefit from lapping. Just make sure to go in one direction and not saw back and forth.

Keep everything really clean by using 91% alcohol on the surfaces before applying AS3.

Have fun!

Oh and try not to move the HS around on the core during the mounting!

Wangster
 
There seems to be some contradicting information on how to actually proceed with lapping. Some people are saying to only go one direction while others are saying to make circular and figure eight motions? Is there any "right" way to do this? Or is it a matter of personal preference and an issue of debat?

I'm guessing either way I do it, I'll probably get better results than if I leave the little ribbed ridges there.
 
Do not do figure eight motions unless you want your heatsink to be convex(i think it is convex it might be concave) but anyway the point is it wont be flat. Get a peice of glass or a mirror as your surface, and pull the sink towards you, lift it up and repeat, dont do it back and forth like a saw.
 
My Results!

Well, at the beginning of this thread, you can see the problems that I was having in keeping my temperatures down. With the suggestions that you folks had, I've since done the following:

1. Purchased and applied AC3 instead of my generic thermal paste that came with the SLK-800.
2. Purchased and installed the Thermaltake Smart Fan II.
3. Lapped my badly machined SLK-800.

I started out lapping my SLK-800. I was reading on these forums and it seemed that some people, myself included, had SLK-800s where the bottom of the HS was badly machined. Mine was bad enough that I could feel stripes lengthwise along the bottom of my HS. It had a ribbed/courderoy type feel and if you ran your fingernail across the stripes, it made a zipper type sound or the type of sound you get when working with zip strips. Anyway, I worked at lapping my HS with 350 grit (they were out of 400) followed by 600 grit followed by 1000 grit wet/dry sandpaper. The whole lapping process took me about 45 minutes or so. I didn't go for the ultra mirror shine. My goal was mostly to get rid of the ribbing in my HS and make the bottom smooth for better contact (and to get rid of remnants of the old cheap thermal paste).

I cleaned up the core of my processor a bit and applied AC3 to the HS and the core very thinly. With that squared away, I tried to be careful and mount the HS vertically not moving it around too much while installing it, but I didn't feel like removing my MB from the case so it slid around a tad. Wasn't much I could do about that.

I then installed the Thermaltake Smart Fan II such that it's blowing towards the HS and processor. It is considerably louder than my last fan, but it's also spinning much faster. I may turn it out after I'm done beating up my box.

Now the meat:

Currently under load my box is running at 43 degrees! That's 8 degrees cooler than it had been running previously! Hopefully, once the AC3 breaks in, I'll even drop further below than that. I haven't tested what my idle speeds are as I've been stress testing my box since I got everything installed. I wasn't patient enough to test it in steps (i.e. how much of a difference lapping made vs the AC vs the new fan). But I can say that I'm extremely happy with the results!

I want to say a big thank you to everyone that posted here and helped me out with everything! You folks are great and gave great advise! Now if you'll excuse me... I'm going to see how much futher this puppy can go now that I have proper cooling. :)
 
Well, I'm at 1.8v and 2400 MHz (12x200) and Prime95 hasn't errored out (yet). I'll obviously have to let it run for considerably longer.

My CPU is at 47 degrees at load with those higher settings. I'm pretty comfortable with that. Although my case temperature is now 5 degrees hotter than it was yesterday. My HSF is doing a good job at dissipating the heat off the CPU... I guess I'll have to work on exhausting that heat more effectively next.

Does it ever end?! :)
 
I hear that...wasn't happy with my 200mhz OC so I went out and dropped a hundred bucks on my HyperX 3500...gained me another 150mhz but I am at 442mhz fsb. Not happy with my idle/load temps so I am dropping another 60 on hsf and about 40 on new case fans....sorry but this is costing more than paintball ( that was only 100 bucks a week :( )
 
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