LEPA LV12 Direct-Touch Heatsink

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Lawrence Lee
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LEPA LV12 Direct-Touch Heatsink

Post by Lawrence Lee » Mon Aug 25, 2014 12:48 pm


walle
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Re: LEPA LV12 Direct-Touch Heatsink

Post by walle » Tue Aug 26, 2014 10:30 am

I suspected it was going to be a bit of a let down on the performance front and the price kind of sinks it. I was surprised to see the sturdiness of that crossbar though, strange the other mounting parts didn't match up.

First class review as always.

Thanks.

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Re: LEPA LV12 Direct-Touch Heatsink

Post by MikeC » Tue Aug 26, 2014 10:47 am

imo, the flexing of the 2 side bars is probably part of the design. All HS mounting schemes have some degree of give -- they have to, otherwise they risk damage to components. Intel & AMD actually specify min & max pressure on the CPU/socket/board by the heatsink mounting.

It's a shame the thing didn't work better. Larry's assessment of the poor placement of the heatpipes through the base seems on the money. The striation of the TIM also clearly shows there's not tight enough contact, due probably to the way the pipes are straddled by the aluminum dividers.

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Re: LEPA LV12 Direct-Touch Heatsink

Post by CA_Steve » Tue Aug 26, 2014 2:16 pm

The center divider plus poor contact were the probable killers.

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Re: LEPA LV12 Direct-Touch Heatsink

Post by walle » Wed Aug 27, 2014 7:44 am

MikeC wrote:imo, the flexing of the 2 side bars is probably part of the design. All HS mounting schemes have some degree of give -- they have to, otherwise they risk damage to components.
Thanks for pointing it out, it actually didn't cross my mind, it should have, but it didn't. Could be because it flexed so much, I don't know.

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Re: LEPA LV12 Direct-Touch Heatsink

Post by MikeC » Wed Aug 27, 2014 8:16 am

walle wrote:
MikeC wrote:imo, the flexing of the 2 side bars is probably part of the design. All HS mounting schemes have some degree of give -- they have to, otherwise they risk damage to components.
Thanks for pointing it out, it actually didn't cross my mind, it should have, but it didn't. Could be because it flexed so much, I don't know.
The tension on the CPU/HS when installed seemed really high. My bet is the mounting system was doing its job correctly -- it's the same type used by the best HS makers. It's most likely that the base is concave in some fashion. Hard to see or measure with this type of base.

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Re: LEPA LV12 Direct-Touch Heatsink

Post by xan_user » Wed Aug 27, 2014 4:22 pm

mike, can you put a true straight edge on the base and tell if the heat pipes sit flush with the ridges? my guess is the copper, being softer, was basically taken down a bit further than the bases ridges were.

i have to wonder what might happen if this thing was properly lapped.

Olle P
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Re: LEPA LV12 Direct-Touch Heatsink

Post by Olle P » Mon Sep 01, 2014 5:15 am

Unfortunately, the LEPA LV12 under-performs, ... due to poor contact with the CPU heatspreader. ...
I think that's jumping the conclusion a bit.
The CPU contact looks okay to me.

Other quite possibly more important problem areas are the small fin area and the relatively thick black thermal insulation layer on those smallish fins.
My guesstimate is that the S.N.T.C. is about as conductive as thermal paste. Much worse than the metal.

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Re: LEPA LV12 Direct-Touch Heatsink

Post by CA_Steve » Mon Sep 01, 2014 10:15 am

Olle P wrote:I think that's jumping the conclusion a bit. The CPU contact looks okay to me.
Compare the Scythe Kotetsu:
Image

LEPA LV12:
Image

If there is good contact, it squeezes all of the TIM out except for a very fine layer that you mostly can't see. If there isn't good contact, you get a thick layer/snowflake pattern.

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Re: LEPA LV12 Direct-Touch Heatsink

Post by xan_user » Mon Sep 01, 2014 6:09 pm

im not questioning the person who applied the paste in this review, but it looks like way more than i like to use.

Im oldschool, i use a fresh razor blade to squeegee the thinnest possible amount of paste that will cover the base, but i also have years and years of experience squeegeing paste in thin coats (screen printing).

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Re: LEPA LV12 Direct-Touch Heatsink

Post by CA_Steve » Mon Sep 01, 2014 7:33 pm

xan_user wrote:im not questioning the person who applied the paste in this review, but it looks like way more than i like to use.

Im oldschool, i use a fresh razor blade to squeegee the thinnest possible amount of paste that will cover the base <snip>
Here's the caption from the review:
Applying thermal paste to a direct-touch heatsink is a more involved process than a normal cooler. As there are gaps between each heatpipe and its neighboring partition, an ample amount should be spread along the length of the partitions (the pressure should spread it out to the heatpipes after installation).

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Re: LEPA LV12 Direct-Touch Heatsink

Post by xan_user » Tue Sep 02, 2014 4:48 am

CA_Steve wrote:
xan_user wrote:im not questioning the person who applied the paste in this review, but it looks like way more than i like to use.

Im oldschool, i use a fresh razor blade to squeegee the thinnest possible amount of paste that will cover the base <snip>
Here's the caption from the review:
Applying thermal paste to a direct-touch heatsink is a more involved process than a normal cooler. As there are gaps between each heatpipe and its neighboring partition, an ample amount should be spread along the length of the partitions (the pressure should spread it out to the heatpipes after installation).
yep i read that. id still use a razorblade to thin out the layer after it was worked into the gaps. if you use a lot more paste on a direct touch cooler,im not sure comparing paste patterns to a smooth base that used way less paste is as valid a test of how good the contact is.

im not saying this cooler would perform any better with less paste. just not sure how valid the snowflake test in this situation.

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Re: LEPA LV12 Direct-Touch Heatsink

Post by MikeC » Tue Sep 02, 2014 8:29 am

xan_user wrote:im not saying this cooler would perform any better with less paste. just not sure how valid the snowflake test in this situation.
In every high performance cooler we've tested, the actual amount of TIM used seemed to have no impact on the actual imprint on the center of the base or CPU: The TIM just gets squeezed out to the perimeter due to the pressure and tight contact. This was true with the few good performing direct-touch coolers as well as the conventional solid base types. We haven't seen the snowflake/fractal TIM pattern w/o a gap between base & CPU.

Having said that, it's still possible that too much TIM was used, and I'm willing to check this by mounting (and removing) the HS again some time later today -- will report back here.

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Re: LEPA LV12 Direct-Touch Heatsink

Post by xan_user » Tue Sep 02, 2014 9:55 am

thx mike. id still love to see/or at least hear what the base looks like with a straight edge on it, with a light source behind it, to see if the copper sits flush with the ridges.

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Re: LEPA LV12 Direct-Touch Heatsink

Post by Lawrence Lee » Thu Sep 11, 2014 11:41 am

xan_user wrote:thx mike. id still love to see/or at least hear what the base looks like with a straight edge on it, with a light source behind it, to see if the copper sits flush with the ridges.
I just examined the base more closely. The partitions and pipes appear perfectly level. The only light peeking through is in the tiny gaps between them.

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Re: LEPA LV12 Direct-Touch Heatsink

Post by xan_user » Thu Sep 11, 2014 12:34 pm

Lawrence Lee wrote:
xan_user wrote:thx mike. id still love to see/or at least hear what the base looks like with a straight edge on it, with a light source behind it, to see if the copper sits flush with the ridges.
I just examined the base more closely. The partitions and pipes appear perfectly level. The only light peeking through is in the tiny gaps between them.
thank you for checking! seems this cooler cant really be saved...

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