ROG Crosshair VIII Impact annoyance with M.2 daughter board

VirtualMirage

Limp Gawd
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Nov 29, 2011
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So I am slowly putting together my new build which will be using the Asus ROG Crosshair VIII Impact for the motherboard. One of the reasons I bought this board was how it was handling the M.2 drives which will be helpful will cooling. However, that special board and its heatsinks are being a bit of a pain.

I am using two Seagate Firecuda 520 2TB PCIE4 M.2s on this build. Removing the heatsinks on the special board and plopping the M.2s was super easy, even remembered to peel off the protective backing on the supplied thermal pads. But as I put everything together, I noticed the heatsink shroud doesn't sit flush like it did before and, in fact, looks a little crooked from the daughter board. So I take a flashlight and look in between and the heatsinks are causing some serious flex to the M.2s. Well, that's not good! Good thing I haven't powered anything up yet and was just doing an inspection fitting.

Looking online, I see multiple people complain about the same thing. Some said the flex is within spec and it will be fine. Others mentioned that there was another piece of padding supplied with the motherboard to put under the M.2s minimize bowing. And here I wondered why there was print on the boards that said M.2 pad. So dug around and found a single piece of padding, not two, with adhesive backings. I looked through the manual and saw no mention of these nor what to do with them. I read online how to use them, remove adhesive and place on the daughter board where it is marked. So I cut the pad in half, which makes it about the right size for placement and did as such.

I put everything back together and the M.2s do bow less but now they seemed to be bowing slightly in two different directions and the daughterboard slot end has a bit of a bow to it. Crap. Did more digging online and some mentioned that the thermal padding supplied is too thick, looks to be 1.0mm and should really be .5mm, at least one side (the underside looks to need the 1.0mm). So I took it apart, again, and decided to modify the thermal padding for the top M.2 by placing it between wax paper and using a rolling pin. I then trimmed off the excess before reapplying. This definitely helped quite a bit, but it still isn't perfect. I then noticed that if all the screws that hold the heatsink shrouds in place are tightened all the way the daugher board wants to torque a little. After fiddling with the screws for about 30 minutes, loosening some tightening others, I managed to get good coverage on the M.2s with minimal bowing and slot on the daughter board is less than a hairs width from being perfectly straight. The heatsink shroud still doesn't sit perfectly flush, but it is close. This may have to do with the screw placement they chose (where it favor mainly just one side and the middle, leaving the other side with no screw down) as well as those extra pads they want you to put under the M.2.

Going back to those supplied pads, I am thinking that they are also too thick since my M.2. have chips on both sides. So the thought is with the thermal pads trimmed and slimmed, maybe this underside pad is no longer needed...but...now I can't get to it. The adhesive is strong and it won't let go of the M.2. Even though the other side is primarily covered with a sticker that has the authenticity hologram and serial number, it for some reason just doesn't want to let me lift up the M.2 and leave the sticker behind. The sticker that was on the other side came off super easy, but that was starting the lift from the edge instead smack dab in the middle. I'm wondering if I heat it up with a hair dryer if will loosen up to allow me to lift it off. But that may be a project for another day.

You pay good money for a premium product and you still find instances where they either didn't think something through or slapped a last minute fix without testing it out. It's not even listed in the manual.
 

thesmokingman

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Get some thinner thermal pads?

Hmm, that is a cya problem. If they supplied too thin of a pad, then m2's might overheat.
 

VirtualMirage

Limp Gawd
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Nov 29, 2011
Messages
359
Get some thinner thermal pads?

Hmm, that is a cya problem. If they supplied too thin of a pad, then m2's might overheat.
I haven't run into any M.2's that are thinner, so not so sure about it being a "thicker" just in a case situation. Because now that it is thicker it torques the daughterboard and bows the M.2s if left unchecked. While maybe it is within tolerance, I can't say, it certainly doesn't look like something you would want to do without having long term issues. Breaking someone's expensive M.2 due to improper fitment vs it not cooling as efficiently causing the M.2 to throttle under its safety settings, sounds like they potentially introduced a greater problem while trying to solve another.

Whether it is QC issue by not supplying the right size pads or a QC issue where there is tolerance variance in the heatsinks and daughterboards manufactured, who knows. As mentioned before, the bottom M.2 seems to take to the thicker thermal pad much better than the top.
 

thesmokingman

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I haven't run into any M.2's that are thinner, so not so sure about it being a "thicker" just in a case situation. Because now that it is thicker it torques the daughterboard and bows the M.2s if left unchecked. While maybe it is within tolerance, I can't say, it certainly doesn't look like something you would want to do without having long term issues. Breaking someone's expensive M.2 due to improper fitment vs it not cooling as efficiently causing the M.2 to throttle under its safety settings, sounds like they potentially introduced a greater problem while trying to solve another.

Whether it is QC issue by not supplying the right size pads or a QC issue where there is tolerance variance in the heatsinks and daughterboards manufactured, who knows. As mentioned before, the bottom M.2 seems to take to the thicker thermal pad much better than the top.

You might want to direct all that to Asus?? I feel you but I gotta say that I've seen too thick pads on a lot of gear. It's not that unusual but if it's that big of an issue you should let them know.
 

VirtualMirage

Limp Gawd
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I will most likely do so once after I get everything up and running, just in case I have a list of things to say. But searching around, it appears there have already been others that have reported this to Asus.

Meanwhile, I went ahead and ordered some Thermal Grizzly Minus 8 thermal pads in .5mm and 1.0mm thickness to potentially swap out what came with the Asus to see if they are a better fit. I am trying to determine if the ones Asus supplied are 1.0mm or 1.5mm and need to be trimmed down by around .5mm for a better fitment. My current workaround, while not perfect, will do for the time being.

Now, to figure out a way to separate the M.2 from the adhesive of the pad they wanted me to put under the M.2 to reduce bowing. It's probably the perfect thickness if there weren't chips on that side, but mine have chips so it's a little too thick. It compresses, but not by much.
 

thesmokingman

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I'd just buy a set of pads. Then mix and match till you get the clearance you desire. Btw, those thermal grizzly are just fuji polys. Fuji makes even higher thermal conductivity pads from 11wmk(extreme) to 17wmk(ultra extreme). Those grizzlys are only 8wmk and the beige colors means they are use once type. They'll shape to their application but will break apart once disassembled fyi. The 11wmk pads which are white are reusable however they don't squish down very well so you need to be more exact. I can't remember about the 17wmk ultra pads, it's been so long since I rolled pads but they're white too so I think they're similar to the 11wmk.
 

VirtualMirage

Limp Gawd
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Nov 29, 2011
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I did see the higher end Fuji polys and thought about getting those (or the probably identical Alphacool versions), but since I am still trying to nail down the exact size needed, I couldn't really beat the price and sizing I found with the Thermal Grizzly's. They didn't have the best thermal conductivity, but they were certainly better than many of the others and (I imagine) may be better than what Asus included with the board. I also heard that the Thermal Grizzly's compressed pretty well if needed, I wasn't so sure about the Fuji Polys in that department. I figured if I manage to nail down the exact size of what's needed, and if the M.2's can benefit from some additional heat transfer, then I will spring on the Fuji Polys then.
 

VirtualMirage

Limp Gawd
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Here's an update:

I think I finally managed to get this board setup to my satisfaction, but it was a pain in the ass.

After comparing it to the 1.0mm and .5mm Thermal Grizzly pads I ordered, the thermal pads that came with the motherboard look to be more around 1.5mm in thickness. It compresses a little easier than the Thermal Grizzly pads, but not by much.

The underside M.2 I used a 1.0mm pad and that seemed to be about spot on. With the screws that secure the cover plate over the M.2, I did have one screw that I couldn't tighten all the way without it starting to flex the daughterboard a bit. So I backed that one out a little and the daughterboard straightened out.

The top side was a lot more challenging. First, it took some effort to remove the M.2 since the double sided pad under it was stuck pretty good to it. I ended up having to peel off the sticker on the M.2 to release it from the pad (I guess there went my warranty on the M.2). I then removed the bad from the daughterboard and cleaned up the board. It was meant to minimize any bowing of the M.2 but its thickness leads me to believe it was intended for M.2s that didn't have chips on that side. With those with chips on both sides, that pad is too thick (it looked to be at least 1.5mm in thickness as well). With nothing under the M.2, the surface of the cover plate to the top of the M.2 isn't perfectly flat and slopes around .25mm from one end to the other. One side needed the .5mm thermal pad while the other needed more. Attempts to cut up the thermal pad so half the M.2 was .5mm and the other half was 1.0mm didn't work because 1.0mm was too thick. While the Thermal Grizzly pad does compress a little, it wasn't enough to make it work. Attempts to use the 1.0mm thermal pad all the way across caused the M.2 to bow.

So what I did was cut smaller strips of the 1.0mm thermal pad (the width of the memory chips) and placed them on the underside of the M.2 where the double sided pad was at. This helped reduce/prevent any adverse bowing from the pressure on the top. I then used the thinner .5mm thermal pad across the whole top and instead of tightening the screw that secures the M.2 all the way down, I left it a little loose (about one full turn from being fully tightened) since the M.2 is kind of spring loaded in the socket. This allows the M.2 to have a smidge of lift needed to allow it to be level cover plate and the .5mm thermal pad to come in contact all the way across, eliminating the .25mm or less of gap that used to be on one end. With the pads on the underside and the full contact on the top, the M.2 doesn't move nor jostle around.

Securing the screws to that top cover plate, it now sits a lot more even than before and doesn't look cockeyed like it did before.

At the end of the day, it may have not made much difference and the board and M.2s may have been within design tolerance for bowing/flex. But it makes me feel better knowing that the M.2s are not bowed and, aesthetically, the daughterboard will look better in the case by not having its cover plates being off cantered. And I guess that's what matters.
 

Nobu

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Is there a second screw in the m2 daughter board or in the mb box? Some of those m2 standoff screws are designed to screw into each other, to add height.
 

VirtualMirage

Limp Gawd
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Nov 29, 2011
Messages
359
Is there a second screw in the m2 daughter board or in the mb box? Some of those m2 standoff screws are designed to screw into each other, to add height.
No, everything that is on the daughterboard is what came in the box. If I am understanding correctly, the standoff you are referring to is what the screw that secures the M.2 to the board is going into and can be moved to different positions based on the length of the M.2, correct?

There is only one set of those that came with it and they are the same size for both sides of the daughterboard. I am using those.
 

Nobu

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No, everything that is on the daughterboard is what came in the box. If I am understanding correctly, the standoff you are referring to is what the screw that secures the M.2 to the board is going into and can be moved to different positions based on the length of the M.2, correct?

There is only one set of those that came with it and they are the same size for both sides of the daughterboard. I am using those.
Yeah, that's the one. My asus b550 board had them taped to the inside of the mb box, so I thought I'd ask.
 
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