Zalman 9500CNPS AT. Good Choice? Lapping? Arctic Silver 5?

[Dougx1317]

I don't know much about heatsinks, but I just bought a Zalman CNPS9500 AT. It is pure copper and has a 92mm fan. Did I make a good choice? (I'm having second thoughts on my choice.) Do I need to lap this? How much temperature difference will I probably see over stock cooling on a Pentium D 925? How much will lapping affect it?

 

[JohnnyLucky]

You made a good choice. Here's a link to a technical review of your heatsink that will answer your questions:

http://www.frostytech.com/articleview.cfm?articleID=2026

 

[Dougx1317]

Thank you for agreeing with my choice and for the great link.

Since I don't do much in heatsinks, I do have a few more questions. Are the following facts about this good, average, or bad? I know the review gives some opinions, but I'd like some personal opinions.

Base Size: 38mm x 40mm
Surface roughness: ~12 microinches
Sound on Max: 53dBA
Degrees above ambient temperatures: 150W= 29.6C 85W= 17.3C

 

[JohnnyLucky]

Generally speaking the heatsink base will match the size of the cpu. Bigger is not necessarily better.

A surface roughness of 12 microinches is fine. It's perfectly acceptable.

Loud sound is the price one pays for a high rpm heatsink fan. Same problem with high rpm fans on high power video cards. It's also a personal matter. One person's quiet fan is another person's jumbo jet engine.

Temps at load that are 20 to 25 degrees above the ambient room temperature are quite respectable.

 

[IzzyCraft]

Well i have a 9700 which i tuned to run about 1800rpm it's as quieter then my gpu at 50% fan speed. I always buy high speed fans but use other means to slow them down till they are quiet enough where the HDD sounds bother me much more. At full speed though it's very loud haha although the rest of my computer at full is like a wind turbine next to your ear.

 

[jsc]

I favor large fans turning more slowly.

 

[Dougx1317]

Thank you for the replies and for being so thorough.

You said it indicates that temp loads are 20-25C above ambient. How does that compare to most stock coolers?

The one thing I forgot to ask about is thermal resistance. It's 0.12C/W. How is that?

 

[Dougx1317]

I'd also like some information regarding Arctic Silver 5 thermal paste. I keep reading people saying how great it is, but I can't find any recent, reliable benchmarks. The company website says:

"PERFORANCE:
3 to 12 degrees centigrade lower CPU full load core temperatures than standard thermal compounds or thermal pads when measured with a calibrated thermal diode imbedded in the CPU core."

Can it really cool a Processor 3-12C or is that just an exaggerated figure? What is the normal temperature difference I could expect on any given processor?

 

[JohnnyLucky]

Generally speaking the good quality third party heatsinks do a better job than most stock heatsinks. However, there was an article and a thread about a new Intel heatsink that did as well as some of the third part heatsinks.

I am growing old disgracefully and I forget stuff but I think a temperature drop of about 3 to 6 degrees centigrade is a bit more realistic for AS5. It would also depend on your pc case's ventilation, airflow, and cooling..

 

[halcyon]

For CPU air cooling its quite important to have a case with good ventilation. What do I mean when I say good ventilation? Something like the Antec 300/900/1200 with a top exhaust fan and at least a 120mm side vent that you can put an intake fan on.

Something like this compared to a case that only has intakes in the lower front and vent fans in the upper back makes a significant difference in my experience.

 

[Dougx1317]

Well, I got this to replace my stock Intel heatsink, so I hope it will do better. A temperature drop of 3-6C isn't much, but for $6 I'll try AS5.

In terms of case ventalation, I have a $30 Raidmax case with no front intake fan, two rear exhaust fans, and a side tube thing. I've 3 Antec 80mm fans and the weird 80mm tube to work with. Any suggestions on the best configuration?

My case: http://www.newegg.com/Product/Product.aspx?Item=N82E16811156044

Full PC Specs:
-Pentium D 925
-2GB OCZ 800
-ECS board
-80GB SATA
-2600XT 512MB GDDR3

 

[JohnnyLucky]

Well, according to the specifications the case has a bottom front 80mm intake fan and a rear 80mm exhaust fan as well as side panel air duct (weird tube?). In the photos at newegg there is an 80mm where the side air duct would be. If you have a side air duct, then you could replace it with your third fan.

 

[Dougx1317]

Well, actually the case I have has 2 80mm spaces as opposed to the 1 120mm pictured. The weird tube is connected (not permanently) to the side vent. It allows air to get to the cpu. The tube seemed to work well with my old cooler, but it probably wont fit with my new cooler.

 

[halcyon]

If you can, replace the weird tube with a 80mm fan. pulling air into the case. with the 2 rear fans pulling air out of the case.

That should take care of circulation.

 

[Dougx1317]

That sounds like it would work well, but the side fan may be blowing directly on top of the CNPS9500 AT CPU cooler. Would that mess up the air blowing sideways through the heatsink?

 

[JohnnyLucky]

It would help.

 

[Dougx1317]

Sounds good. I'll let you know if I have anymore questions when I get the cooler. Thanks for all your help.