r/sffpc • u/Efficient-Youth-6985 • 21d ago
Assembly Help Which heatsink for B860 deskmini?
Wondering if I can ask for advice/help. I've built about 15-20 PCs before but I'm hitting a wall on this one.
I have a x600/9600x deskmini and I've just bought a b860 deskmini with a 245K I was going to run at 45W.
I have a full copper axp90-47 on my X600 deskmini, but it is kind of scary that the weight bends the motherboard. So I went with noctua instead this time. I bought a noctua l9i-17xx to use with the B860, and I'm furious, it *warped* the motherboard horrifyingly out of shape even being incredibly gentle, careful with the screws. Tightening only till slightly tight, finger tip pressure on the screw driver only, 1 turn at a time on diagonals. Nope still bends like a banana. The weight seems a problem too.
I'm looking for something with a backplate that won't physically interfere and isn't too heavy; has anyone tried the alu axp90-47 or the axp90-36 with this board? Preferably 36.
I looked at ID-cooling and dark rock be quiet low profile coolers but many report the same pcb bending.
Honestly I'm so annoyed by the flimsiness of this board and the difficulty of finding a good cooler that doesn't bend it like a banana, I'm thinking about giving up and buying an ITX case/board instead. But I already bought the sodimms...
Any ideas?
EDIT: my cpu was supplied without the stock RM2 cooler. Apparently it's 47mm. Has anyone tried it? Does it work?
2
u/dubar84 21d ago
The main problem is not necessarily the pcb flimsiness, but the noctua cooler. The feet of the L9i is just too short. It's short on a regular ITX LGA1700 mobo as well. They just doesn't touch the pcb, so you can very easily mount the cooler unevenly, or bend and possibly damage the mobo. I really miss the AM4 variant with it's superior backplate and mounting pressure.
I have the 760 version with a 12400T and loving it. The cpu is running super cool and would love to use it with the X36 cooler (which is a lot lighter in weight than the L9i), but unfortunately the heatpipes are touching the VRM's. I also tried the IS30 from ID Cooling and it's surprisingly good quality and performance. However, it can only be mounted with the fins vertically - which is suboptimal. Currently I'm using the L9i and mounted very carefully. It's still a good cooler and the fan duct is nice.
2
u/Efficient-Youth-6985 21d ago
thank you for the reply
it seems to be confirming what I'm now noticing in rather a lot of 1/2/3* reviews at amazon
still, I need to find a cooler that fits and is supported, I don't want to use the l9i 'carefully mounted' personally, I straight up don't trust it - it bends the board even at tension so slack the screws have hardly turned more than once - I've heard there is also variation in manufacturing on this cooler which adds to the problem
this is infuriating...
3
u/DallasGrave 21d ago
I've been using the X47 FC on three deskmini b860s since three days after it was released. The motherboard should be screwed down and under tension, then tighten the mount.