Zalman CNPS9500 Base NOT Flat

[gswilder]

Last week I purchased a CNPS9500 LED CPU heatsink for my new PC. It is for an Epox 9NPA+SLI board.

My concern with the new CNPS9500 is that the base of the heatsink is not flat. It has a curve to it. When I sat the heatsink on a flat surface, it rocks back and forth. I did some searching, and there are several others having the same issue. Even the Frostytech site noted the problem in their review. Not sure if all are like this or just a bad initial batch. I was somewhat hesitate to put on my $900 dollar AMD 4800x2, but went ahead.

If the base was flat, I think you could get into the low 30c's. Not sure if anyone else here has noticed the same problem. And just wanted to give everyone a heads up.

Let me know,,,

Greg

 

[Markbnj]

Hmm, I can't imagine that's good, even if you fill the gap with thermal compound. Wonder if this has anything to do with why Newegg is out of stock.

 

[Remedy]

I thought I read some article recommending that you lapp it down because the surface was concave?

 

[JEDIYoda]

I installed the Zalman 9500 on my system with no problems!
The base was very flat!!

Very easy install!!
My idle temp is a rock solid 27c.......ambient temperature is approx 75 degrees farenhiet...

I have not read of that being an enormous problem considering almost all brands of heats sink occasionally have a few with that problem!!

Generally speaking lapping is never recommended by any of the heatsink manufactureres yet sometimes you have to do what ya have to do!!

lets just hope you are lapping correctly!!

 

[Jimmah]

Belt sand it flat, or mill it, or have it professionally ground and properly lapped and not that BS home lapping crap everyone else does.

 

[Elcs]

Contact Zalman, see what they recommend you do.

Id rather RMA it to get a flat one rather than try to lap it and mess something up.

 

[GalvanizedYankee]

Originally posted by: Jimmah
Belt sand it flat, or mill it, or have it professionally ground and properly lapped and not that BS home lapping crap everyone else does.

Please tell me the BS stands for"before school." :laugh:

Anyone with the proper materials and one practice session can do a very acceptable job
of hand lapping.

What would one practice with?? The retail HS will do nicely,t/y.

A belt sander?? YIKES!!:Q This fits with the post on using an X-Aecto knife to remove
thermal tape. lolol

Mill it?? At $100 an hour a machine shop's time for set-up would scare you.


Galvanized

 

[Jimmah]

Nothin wrong with a horizontal belt sander with a fine grit, just have to use common sense and be careful. Afterwards you could buff the surface to a fine polish.

 

[George Powell]

The one problem that lapping a heatsink at home is that most people can't check to see how flat the surface actually is.

Must try and get some time on a CNC machine and make a heatsink, that would be cool.

 

[CraKaJaX]

That just might be a problem......

 

[Jimmah]

Originally posted by: George Powell
The one problem that lapping a heatsink at home is that most people can't check to see how flat the surface actually is.

Must try and get some time on a CNC machine and make a heatsink, that would be cool.

Agreed, but if you can get ahold of a surface grinder that would make for a nicer surface finish. Once I get some spare time I intend to do that very thing at school then a good buff on the lathe. Course, with CNC you could make some pretty cool heatsink designs ,like a pyramind or something.

 

[gswilder]

It kept the 4800X2 CPU at around 38-40c at pretty much idle. Seems kind of high to me. However, I have tried 2 other CPU coolers and all are about the same temps. (Big Typhoon, SI-120). All using AS5 or AS Cermanique)

I like the Zalman, but may have to return it to Newegg.

 

[JEDIYoda]

just RMA the zalman 9500 have them send you another.....

I know alot of people and your 9500 is truly the exception...

good luck!!

 

[davexl]

The got a warped 9500 too! Just posted this of DFI-Street:

Just reporting some results that might be useful to people looking at CPU coolers for their X2 / DFI Ultra-D.

I went from a Zalman 7700-Cu to a defective Zalman 9500 to a Big Typhoon.

Cut a long story short, the 9500 plate had a slight concave warp, would not hold flat to the CPU, and the airflow did not suit my case. Returned it and got a Typhoon.

I originally went with the 9500 as it was light, and cheaper than the xp-90/120 where I am from. Typhoon was my next choice - cheap, but a tad heavy and a pain to install, but it suits my side air intake.

My load temps - all at 20C ambient, MBM5 average 30 mins, dual Prime95, (not counting first 5 mins of test) 2585Mhz, Vcore - 1.375 +110%. Antec 3000 case with side intake, no significant front to rear airflow.

Zalman 7700 Cu - 50c
Zalman 9500 - 50C
Zalman 9500 - 48C (with extra 120mm fan blowing on PWMIC/CPU area)

Big Typhoon - 44C
Big Typhoon - 42C (with extra 120mm fan blowing on PWMIC/CPU area)

8 degrees is good, but it gets better? the higher you go the better the Typhoon gets. At 1.425v +110% my temps have gone from 56C to 45C!
The Typhoon is rather tall and heavy and I would not think of transporting it like this, and may even brace it with some cross wires, and remember not to kick it under the table! The fit and finish on the Typhoon is crap, the screws are the wrong size, needing some spacers to work. Installation is very tricky due to the overhang ? hard to screw it in.

But all this means nothing, as my first attempt at installation without time for the AS5 to cure has given me a 11 degree drop in load temps, in fact, so much I am trying voltages that were simply out of reach before.

Woot!