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Megahalems vs TRUE: Stock Comparison on Overclocked i7 Platform

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baditude_df

Northern Senior
Joined
Apr 24, 2007
Hello, and welcome to my comparison of the Prolimatech Megahalems to the Thermalright Ultra 120 Extreme (TRUE).
This is an "out of the box" comparison, and is strictly to test the thermal performance of these two heatsinks with stock base and mounting with no modifications whatsoever.
The comparison was done in an environment that is as controlled as possible without having laboratory conditions or equipment.

Test Setup:

General:

  • Both heatsinks will be tested on my bench in open air. When reference is made to Ambient Temperature, that is actually Ambient ROOM Temperature.
  • System Specs (Frequeny, Votage, HT etc.) are in my sig. Cooling Specs below.
  • If you want a rough breakdown of Fan Specs at each Voltage setting just divide into 3 equal divisions, keeping in mind that this controller only gives 11.3v rather than a full 12v at max setting:
    ie: 12(11.3)v=2400RPM,95cfm,35dBa,55Pa 10(9.42)v=2000RPM,70cfm,30dba,45Pa 8(7.54)v=1500RPM, 50cfm,25dba,30Pa
    Fan voltages were measured with a multimeter. The rest (RPM,Airflow, Pressure, Noise) can only be estimated. But from what I can tell it's pretty darn close.

The Bench:



HeatSinks:
1 TRUE Black (Original)
1 Prolimatech Megahalems

FAN(S):1 Sanyo Denki San Ace 109R1212H1011 (Shrouded 25mm, Push Pull added later on for 4.4 and 4.6GHz stops)
Current......................................... 0.52A
Watts............................................ 6.24
RPM ............................................. 2600
Flow CFM (Max)............................ 102.4 CFM / 2.9 cu metre[m3]
Static Pressure (in. H20)................ 64.7Pa (6.6mm)
Noise (dBA).................................... 39.0
CONTROLLER: Sunbeam Rheobus 6Ch.
TIM: AC MX2

Test Methodology:

  • Each heatsink was tested from 8(7.54)v to 12(11.3)v fan settings in 2V increments.
  • Each heatsink was tested for 10 minutes at each fan speed with Prime95 Small ffts. After which, Core Temperatures were recorded with RealTemp 3.36. Individual core temperatures can be seen in each screencap link.
    For graphical purposes, temperatures have been averaged. I'll warm things up prior to the 8V test to create the same conditions the rest of the fan setting tests will see.
  • After the single push fan test, each heatsink was fitted with a second fan for push/pull testing.
  • Each cooling setup was tested at the same ambient air temperature of 21degC. Temperature was taken before and after each heatsink was tested to confirm a consistent temperature.
  • Each heatsink was tested at 4.0GHz with a vcore 1.264v

Enjoy!

Megahalems

Results Screenshots - Single Fan:

--------------8v----------------------------10V-------------------------12V-----------

Results Screenshots - Push Pull:

--------------8v----------------------------10v-------------------------12v-----------

Thermometer Shot B4
Thermometer Shot After

TIM Application


TIM Spread


TRUE

Results Screenshots - Single Fan

--------------8v----------------------------10V-------------------------12V-----------

Results Screenshots - Push Pull:

--------------8v----------------------------10v-------------------------12v-----------

Thermometer Shot B4
Thermometer Shot After

TIM Application


TIM Spread


Overall

charto.gif


Observations

Pretty much as I expected really, a close match. Both coolers performed very well. However, there are a few things I'd like to mention:
  • The base on my TRUE is very flat. For a stock TRUE out of the box, this would tend to be the exception rather than the rule. I think that pitting the megahalems against any other stock TRUE could likely yield different results.
  • The mounting mechanism for the Megahalems, while well designed and easy to install, did not provide as much tension as I'd like. From what I observed (see TIM spread pictures) the TRUE did provide more stock mounting tension at max. However, IMO both coolers did get a good even spread and adequate thermal bond.
 
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OP
baditude_df

baditude_df

Northern Senior
Joined
Apr 24, 2007
Yup, np. :)
I'll do a couple more seats with this Mega since it's my first time using it. I'd like to see if it responds better to a line or spread method of TIM application. I used enough TIM, but the heatsink base just didn't get squeezed down hard enough IMO.
 

bing

Low Profile Senior
Joined
Jul 13, 2006
Location
Indonesia
Thanks for the great review baditude, really appreciate it. :thup:

However, there are a few things I'd like to mention:
  • The base on my TRUE is very flat. For a stock TRUE out of the box, this would tend to be the exception rather than the rule. I think that pitting the megahalems against any other stock TRUE could likely yield different results.
  • The mounting mechanism for the Megahalems, while well designed and easy to install, did not provide as much tension as I'd like. From what I observed (see TIM spread pictures) the TRUE did provide more stock mounting tension at max. However, IMO both coolers did get a good even spread and adequate thermal bond.

From your TIM spread shots, I downloaded the full size (hope you don't mind :) ) and made them side by side like this here for better comparison, the left one is TRUE, and Mega at the right.
TIM Spreads.jpg

Assuming you've pulled them both from the same angle, direction and without twisting the HSF when pulling , this pic above shows the TRUE base contact to the IHS is really good while the MEGA is not optimal, either not flat enough "OR" not enough tension as you mentioned. If you've done flatness checking using glass & dye/ketchup like these HERE or HERE, then you'll understand what I mean on those TIM pattern.

Now regarding the MEGA mounting, I had a really high expectation on it's design and you said it didn't have enough tension, mind explain further ? Apart from the TIM spreading, have you observed the mobo bow/curved when mounted ? Yes, even with backplate, it will still curve "abit" if you watch them closely. :)

I have TRUE myself and mounted using the H bracket from Tuniq Tower which provides a really good tension, far better than the original.

Again, really thanks for the effort, great job ! :clap:
 
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Brando

Member
Joined
Jan 9, 2006
Nicely done, much more detailed than my test. Strange that we got opposite results though. I thought maybe I lapped wrong at first but when I looked at the reflection of my computer screen on the base of the true all of the test looked straight. Maybe not enough tim? I know it had enough pressure at least. I think most of it was the fact that the TRUE was dusty and the mega was spotless. I'm still waiting for the Mega to get filthy so I can test again.
 
OP
baditude_df

baditude_df

Northern Senior
Joined
Apr 24, 2007
Thanks for the great review baditude, really appreciate it. :thup:



From your TIM spread shots, I downloaded the full size (hope you don't mind :) ) and made them side by side like this here for better comparison, the left one is TRUE, and Mega at the right.
View attachment 77674

Assuming you've pulled them both from the same angle, direction and without twisting the HSF when pulling , this pic above shows the TRUE base contact to the IHS is really good while the MEGA is not optimal, either not flat enough "OR" not enough tension as you mentioned. If you've done flatness checking using glass & dye/ketchup like these HERE or HERE, then you'll understand what I mean on those TIM pattern.

Now regarding the MEGA mounting, I had a really high expectation on it's design and you said it didn't have enough tension, mind explain further ? Apart from the TIM spreading, have you observed the mobo bow/curved when mounted ? Yes, even with backplate, it will still curve "abit" if you watch them closely. :)

I have TRUE myself and mounted using the H bracket from Tuniq Tower which provides a really good tension, far better than the original.

Again, really thanks for the effort, great job ! :clap:

Hi Bing, I think this is the first time you have posted in one of my threads, nice to see you here. Both heatsinks were removed with my standard 1/8th"(or as little as posssible)turn clockwise and pull method.
Flatness test was done with an Olfa Heavy duty razor blade. Both IHS and Heatsink Bases were done and found to be in the shape they are supposed to be in. The mega in particular is convex parallel to the long axis and perfectly flat in the short axis, much the same as my Apogee GTZ and EK Supreme were. The next set of tests will be to apply the TIM with the line method and in a spread method.

As for the mounting, it's awesome! Very solid, easy to install, holds the backplate in place without two sided tape, and holds the heatsink IN PLACE!
But when I was tightening down the screws and they bottomed out, I was like "wtf???" "So Soon?"
Now, this might be the way it's supposed to be done, but even with the flex that is built into the TRUE's mounting kit, I know the true is getting more tension. And no, absolutely no flex was observed in the Mega's mounting kit. Again, it's solid!
SO to answer your question, I think that it was the tension alone that caused the "less than optimal" TIM spread. As you can see it was off to a very good start, with an even spread moving outwards, it just needed a little more sqeeze!

Nicely done, much more detailed than my test. Strange that we got opposite results though. I thought maybe I lapped wrong at first but when I looked at the reflection of my computer screen on the base of the true all of the test looked straight. Maybe not enough tim? I know it had enough pressure at least. I think most of it was the fact that the TRUE was dusty and the mega was spotless. I'm still waiting for the Mega to get filthy so I can test again.

Hi Brando, I'll re-itterate that the base on my TRUE is excellent. I know that's kind of funny to hear, but it's the best I've seen for an original run(ie: Not rev B or C). Maybe it has something to do with the fact that it's a Black Series, idk.
Also, I haven't done any research on the Mega's base, but the way the base is designed (Slightly convex in one axis/flat in the other) is just too perfect, and I have to assume it was purposely designed and machined like that. I lined up the heatsink the way that most people would intuitively line it up in their cases, and did the test.
For me intuitively, the long, convex asis should be alligned with the long axis of the CPU (ie: with the cores) so I will be trying a new seat this way, using the line method of TIM application in my next set of tests.
 
OP
baditude_df

baditude_df

Northern Senior
Joined
Apr 24, 2007
Megahalems vs TRUE: Reseat on Megahalems (Line Method)

Well, TIM application method definitely makes a difference with the Megahalems. I wasn't expecting quite this much though.
The TRUE was not tested with the line method, as I know this heatsink does not take well to it at all(typically adds ~5degC).

Overall

charth.gif


Megahalems

Results Screenshots - Single Fan:

--------------8v----------------------------10V-------------------------12V-----------

Results Screenshots - Push Pull:

--------------8v----------------------------10v-------------------------12v-----------

Thermometer Shot B4
Thermometer Shot After

TIM Application


TIM Spread


Observations

Some interesting information has come out here I think (and forgive me if this is already common knowledge to some):

  • The TRUE seems to be superior at lower fan speeds. I find this odd since the original TRUE has a more dense fin pattern than the Megahalems.
  • The Megahalems shows a much larger temperature spread between fan speeds(in particular between 8v and 10v).
    Whereas the TRUE seems to best it at low fan speeds, the Mega quickly steps things up, and even passes the TRUE as fan speed increases to ~2000RPM.
    With a single fan configuration, the TRUE and Mega seem to perform the same at the max fan speed setting of ~2400RPM. In Push pull, the Mega seems to out perform the TRUE after ~2000RPM.
  • Please keep in mind, that even though the Megahalems is leading the TRUE in this test, we're talking about less than a degree throughout the fan speed range.
    The larger differences are seen while comparing the same heatsink in single fan vs push pull configurations.
 
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zangler

Member
Joined
Sep 19, 2001
Location
Houston, TX
very nice test...but i think you should go ahead and try the line method for the true also...i just did it on my cogage true and it made a huge difference...
 
OP
baditude_df

baditude_df

Northern Senior
Joined
Apr 24, 2007
I should have been more clear.
When I said:
The TRUE was not tested with the line method, as I know this heatsink does not take well to it at all(typically adds ~5degC).
What I meant was, I've tried it many times in the past and believe me this heatsink does not like the line method no matter what.
Just for S&G I tried it again today to see if I could tweak the spread pattern a little bit, and just as I expected, mid 40's idle and mid 70's load at 4GHz with full fan speed and 21deg ambient.
As soon as I popped it off and put a dot of TIM on, Viola! No hassle, dab and mount. Mid to high 30's Idle and mid sixties Load.
As far as I'm concerned, there is only one way to apply TIM with this particular Heatsink.
And for the record, this is the same heatsink that I paired up against my water loop a while back(link) and that stacked up very well against it at 4 GHz.
While I acknowledge the fact that there is always room for improvement, I've done about all there is to do with this cooler besides lapping the base, and it has repeatedly exceeded my expectations.
 
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bing

Low Profile Senior
Joined
Jul 13, 2006
Location
Indonesia
As for the mounting, it's awesome! Very solid, easy to install, holds the backplate in place without two sided tape, and holds the heatsink IN PLACE!
But when I was tightening down the screws and they bottomed out, I was like "wtf???" "So Soon?"

Thanks for this important info, I guess they should mod the mounting design, instead of screwing down, probably they should change the design using nuts from above for tightening to the screw that is pointing upward.

Cause with current design, it seems like there is a chance that the screw will crush the mobo's cap below that black bracket if you over tightened, or say people using different longer screw, is that possible ?
 
OP
baditude_df

baditude_df

Northern Senior
Joined
Apr 24, 2007
Ummm, nope, no danger of crushing anything as far as I could tell. I don't think the screw protrudes below the plate when fully tightened.
One way you could easily increase the mounting tension is to place a washer or two between the screw springs and cross plate. I pretty sure this could have helped, I just didn't feel like going down to Home Depot to get washers.
However, I think the TIM re-application was enough to get this heatsink performing to full(or close to full)potential, and that the mounting tension is pretty much right where it needs to be to work as intended.
 

MattNo5ss

5up3r m0d3r4t0r
Joined
Aug 11, 2008
Very good job!

It's surprising how much the TIM application type changed your results.

It's always good to have a few washers laying around :D
 
OP
baditude_df

baditude_df

Northern Senior
Joined
Apr 24, 2007
Yeah, it's a great mounting system, but a funny one. The back plate and side rails, just kind of sit there and actually sink down into the mounting holes in the PCB about 1/8", when they are fully assembled. This brings the side rails down to about the level of the IHS. Then you apply the TIM and seat the sink, then put the cross rail in and it pretty much sits flush all the way accross. Then you screw in the spring loaded screws, which pulls up the base assembly and backplate along with it. Then once the back plate is pulled up flush with the back of the mobo, the remaining threads use the power of the spring to provide the tension on the heatsink base. Personally I'd like another few milimeters of stroke on that screw.
Or at least I think that's how it works. I really need to look into that further.

I think that maybe using washers around the two metal pegs between the cross rail and the Heatsink base would be the way to lift the assembly to the point where the springs on the mounting screws would be providing tension throughout their entire stroke.
I should really try it b4 I give this thing away next month.
 
OP
baditude_df

baditude_df

Northern Senior
Joined
Apr 24, 2007
Bump for those considering one of these coolers or debating between the two.
 

Alien432

Tech Savvy Member
Joined
May 30, 2008
Location
Kansas, USA
Great job on your HSF analysis! :thup:

I got both HSF and well I get lower temps with the Meg and the Prom thermal paste that came with it. Cost wise the True is better value.