Epiphany-III chip airgap / heat-spreader height differences!

[deviantlamb]

Okay so shortly after receiving my board, imaging up a usb and successfully ssh'n into the unit I was amazed at the heat the chip was reporting back. so amazed I immediately halted, inspected the TDP and likewise specks closer and went off and got myself a more suitable heat sink. see here if your keen: alphanovatech >

So long story short here are some photos, static wise i'm earthed by an ankle strap to the bare metal of a fridge foot.
Now that I am aware that there is uneven/ziltch/no heatsink contact on the hotter chip I will need to get myself a copper spreader of the ideal thickness to equal this out. Do all owners of this board know that they are potentially looking at running a bare chip? have you checked yours? for those that this is ooold news, how did you solve this issue?Again for those that don't, go check yours!






That last pic: [topic] that damn air-gap/height difference

[deviantlamb]

updated to actually show the images

[greytery]

Nice (alternative) sink!

I upgraded to a 4-way cluster by adding a pair of the later 7010 headless microservers with the newer slab sink.
So I also noticed the air gap above the Epiphany. That's the cooler chip BTW, but I agree that it's a bit scary.

However, I'm using instead of the adhesive tabs. I applied a slightly more generous amount of the paste to the Epiphany than to the Zynq - so no visible gap.

Note: the paste is very thick - warm it under your armpit for a while to make it easier to apply. Your climate and body temperature may vary.

Cheers

[AndyC]

Hi Deviant lamb,

I had a look at mine and as far as I can see the pads supplied with my heatsink are in contact ok with both chips.

As Greytery says though it is the zynq that gets very hot, for mine there is no way even with the large heatsink provided that you can run it without a fan.

I'm running a 12V 6cm fan at 5V attached to the top of the heatsink pulling air through the heatsink, this keeps mine at 55-57C. Just incase something goes wrong I also have a daemon running monitoring the temp that sends messages to the console incase it gets too hot. Unfortunately there is no way to power down the board from software if this happens.

Cheers

Andy

[deviantlamb]

[deviantlamb]

AndyC,

Yea a service I started to poll chip temperatures alerted me to the initial high temps at idle. I have since modified the thresholds to suit spec. I will get around to making it send me notifications via mutt or a LAN message service at some point. (I might pastebin my handiwork)

Cheers.

[greytery]