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Saturday, January 8, 2022

Intel heatsink mounting brackets on my AM4!

 I bought a Zalman ENPS10X Optima tower heatsink for my old FM1 a long while ago.  It was overkill, but I bought it at a discount. AMD changed the mechanical spec for AM4 socket, so it couldn't be used.

AM4 vs FM1/FM2/AM3


Mounting kit for my old heatsink

Zalman updated the rev. 2 of the heatsink by changing the backplate and the 2 pieces of springs for the AM4 with both sets of mounting holes.  

New heatsink mounting kit

They offer an AM4 upgrade kit for some of their other heatsinks for $11, but not my old model.  That's 1/2 the price of what I paid for and I'll be taking a gamble.  The old springs are too narrow.  I'll have a very hard time trying to drill it without good carbine drill bits and a drill press.  I am using the Intel mounting kit as it leaves just the right amount of space for the extra screws holes.

I placed the heatsink on top of the AMD Wraith Spire.  It turns out that the fan mounting hole lines up with the Intel 775 mounting holes.  I took advantage of that for my alignments.

Zalman heatsink (with Intel mounting kit) on top of Wraith Spire

I use some scrap piece of "stiffener" 0.06" thick plated mild steel from a server card to make my adapter.  I measured off 54mm spacing for the backplate mounting hole.    The hole sizes are 9/64" and all the screws for this project are 6-32.

I use cooking oil as cutting oil for drilling.  Once that's done, I lined it up to my set up and mark off the mounting holes for the springs.  I used the first mounting bracket as a template for the second piece.

My mounting bracket

I got a bit head of myself without thinking about how to equalize the spring tensions of the four corners. The original screws (metric) have short threads. I only have the full thread screws.  I made a wild guess and used some #8 nuts as thick washers that acts as a stop.

Bottom view of the finished bracket
Heatsink mounted using the backplate that came with the motherboard.

The heatsink fits

How well does it works?  I ran P95 for stress testing the set up with a 3.7GHz Overclock and 1.275V undervoltage. The CPU junction temperature is at 75.3C with CPU at around 131W when all fans are running at 100%.  This is actually slightly better than the other heatsink I was using before for the same PC.

Thermal result on my Ryzen 1700

I decided to swap the old heatsink back and use this heatsink with my Ryzen 5800X PC.  I did some minor clean up to replace the screws with pop rivets to make more height clearance for the motherboard components.  This time I super glued the 4 nuts/spacers in place.  I also have to trim off the top left bracket as it was running a bit too close to the VRM capacitors on my new motherboard (not shown).

Heatsink bracket with some minor clean up.

I ran Cinebench as a way to warm up the thermal paste before removing old heatsink.  I used a 2 fans push-pill configuration trying to get the 5800X thermal under control.

The Before picture with the old heatsink (Thermaltake Contac Silent 12)

Here is the same test again with this heatsink also in a push-pull configuration.

The After thermal with this heatsink (Zalman ENPS10X Optima).

The Zalman is about 2.3C cooler and has a slight higher Cinebench R23 score (15225 vs 15133) as it has a slight higher (thermal throttle) frequency limit (4480MHz vs 4475MHz).

Thermaltake probably sourced a commodity heatsink that have the cutouts that supports a rotated orientation not used here. The bottom part (5mm or so) of the fan is not fully covered by the heatsink allowing for  some airflow under the heatsink. For some reasons, they added fins on the baseplate perpendicular (instead of parallel) to the airflow. This messed up the airflow and collects dust.  They also did not include a pair of clips for adding a second fan.

Zalman fan has a higher top RPM and interesting enough they didn't mill the heatpipe flush with the rest of the aluminium baseplate. The top part of their baseplate is smooth.  This would probably help cool the short VRM heatsink down stream.

Thermaltake heatsink side view. Blue arrow show air flow from fan below the heatsink.

The Zalman in my Ryzen 5800X PC.

P95 stress test at Package Power = 100W