I have got 7W/mK by Phobya, i`ll use.
Heatsinks are not good polished, lots of space in there. I`ll cut a square of phobya pad and screw heatsink on it.
As i said before, i got 0.5, 1.0 and 1.5mm - witch should i use ?
Topic: ZTEX USB-FPGA Modules 1.15x and 1.15y: 215 and 860 MH/s FPGA Boards - page 20. (Read 182443 times)
April 29, 2012, 06:27:50 AM
April 29, 2012, 06:19:17 AM
Using pad`s and grasse is kind of strange...
Look at the thermal conductivity and resistance numbers for whatever you are using. Using pads and grease is completely not useful unless you need to operate on a very much non flat surface and even there just grease will probably do a better job.
You see, good grease like MX-4 is rated at 8.5W/mK (higher is better), most greases I find in computer stores are at 1~3W/mK and most pads will fall at around 1W/mK. I have tried some high end thermal pads rated at around 6W/mK and some very good phobya ones at 7W/mK, but because the heatsink with the pushpins doesn't apply enough down force to compress the pads as designed, the result is that even 3W/mK grease works better than the best of pads.
I could use thicker pads but then thermal resistance comes into play and offsets any gain the pads could have on the grease. The pads (at least the very good ones) still have a place in testing scenarios as it is so much easier to snap on heatsink out and another in without having to clean up the grease mess left behind
So, in a nutshell, if you use grease+pad (+grease?) you will have the thermal conductivity of the worst link and the combined thermal resistance... not very useful.
April 29, 2012, 06:18:08 AM
This unit seems to have died on me while i was playing arround with the Quad and the others.
I don't think so. I had this issue with both the 1.15x and 1.15d. It happened both times after removing and reconnecting them. I think the problem is on the micro USB side. Try there.
Same issue here, after repowering und reconnecting the boards (usb and power) several time, it worked again.
April 29, 2012, 06:10:18 AM
This unit seems to have died on me while i was playing arround with the Quad and the others.
I don't think so. I had this issue with both the 1.15x and 1.15d. It happened both times after removing and reconnecting them. I think the problem is on the micro USB side. Try there.
April 29, 2012, 05:53:50 AM
Using pad`s and grasse is kind of strange... I`ll use my best pad for one chip today and i`ll see.
seccond think is, to put small heatsink on bottom of the board, small aprx. 75x75mm in the center of the chip.
and the last think is, to put water block on it...
i got one to use...
those FPGA are real fun i must say.
seccond think is, to put small heatsink on bottom of the board, small aprx. 75x75mm in the center of the chip.
and the last think is, to put water block on it...
i got one to use...those FPGA are real fun i must say.
April 29, 2012, 05:49:11 AM
Using pad`s and grasse is kind of strange... I`ll use my best pad for one chip today and i`ll see.
seccond think is, to put small heatsink on bottom of the board, small aprx. 75x75mm in the center of the chip.
and the last think is, to put water block on it... i got one to use...
those FPGA are real fun i must say.
seccond think is, to put small heatsink on bottom of the board, small aprx. 75x75mm in the center of the chip.
and the last think is, to put water block on it...
i got one to use...those FPGA are real fun i must say.
April 29, 2012, 05:42:00 AM
Tried that on two pcs.... Nothing helped so far. This unit seems to have died on me while i was playing arround with the Quad and the others.
April 29, 2012, 05:07:54 AM
One of my older singles seems to be dead for no reason ..... It won't be recognized buy the mac (or any other PC i have in my household). It's listed as an unknown device under the Hardware Manager (Widows 7) and as i try to install the Ztex driver for this i always get the error: "There is no Driver ....blah blah blah".
I know this problem. Try to plug it in and out repeatedly. If that does not work, shut down the computer and disconnect all devices. Start the computer and reconnect the boards one by one. My advice is to not remove them once connected and running.
April 29, 2012, 04:56:07 AM
try also this:
i use pad to contact the pcb to avoid to scratch and of course some grease.
the board runs 220MH/s@220MHz stable.
the second fan is necessary to transport the heat away.
the second heat sink can be smaller but i have only this at the moment. so i was taking this.
i use pad to contact the pcb to avoid to scratch and of course some grease.
the board runs 220MH/s@220MHz stable.
the second fan is necessary to transport the heat away.
the second heat sink can be smaller but i have only this at the moment. so i was taking this.
April 29, 2012, 04:46:09 AM
no that'll kill your board!
My new single works with the old bitstream but not with the new ....
My new single works with the old bitstream but not with the new ....
April 29, 2012, 04:42:10 AM
No. Do I have to use the pad and thermal compond???
No, you should put about the amount of a tip of a match on to the chip, then spread it evenly. Then put the heatsink on top and attach it using the metal parts and nylon fasteners to the board. Move it around a bit and you're set.
[EDIT] Sorry I noticed you tried this allready. I would say your heatsink is not 100% flat. Try using little extra AS5, put it in the middle, don't spread, press heatsink on and clip it in, then move and twist it a bit to get a better spread.
April 29, 2012, 04:23:03 AM
Will the fpga reach the burnin temprature (>58 celsius)?
The die will certainly reach that temperature, however not the case if it is cooled properly.
The "bad" thermal connection before that burn in happens is probably sufficient to keep it from going up that far.
AT YOUR OWN RISK: Your best bet might be to put the board into a precisely temperature controlled oven at ~80°C for a couple of hours.
April 29, 2012, 04:20:25 AM
Now a test to prove my theory.
I've applied some new AS5 and scrachted it linear very slightly. Then I've put the heatsink and moved it around a little bit. With the same result: the heatsink touches only at the corners. Here are the photos:
http://25.media.tumblr.com/tumblr_m38gp7e1oF1ruij9wo1_1280.jpg
http://26.media.tumblr.com/tumblr_m38gpjH9L71ruij9wo1_1280.jpg
What can I do???
I've applied some new AS5 and scrachted it linear very slightly. Then I've put the heatsink and moved it around a little bit. With the same result: the heatsink touches only at the corners. Here are the photos:
http://25.media.tumblr.com/tumblr_m38gp7e1oF1ruij9wo1_1280.jpg
http://26.media.tumblr.com/tumblr_m38gpjH9L71ruij9wo1_1280.jpg
What can I do???
That's why I usually prefer the "blob in the middle, then put on heatsink and move it around a bit" method.
April 29, 2012, 04:16:26 AM
What do you think about these Liquid Metals Pads (http://www.coollaboratory.com/de/produkte/liquid-metalpad/)?
Do they work with the plastic case of the fpga?
Will the fpga reach the burnin temprature (>58 celsius)?
Do they work with the plastic case of the fpga?
Will the fpga reach the burnin temprature (>58 celsius)?
April 29, 2012, 04:08:33 AM
Did you use the thermal pad that came with the heatsink? Maybe this is the issue here.
No. Do I have to use the pad and thermal compond???
Something like this:
HEATSINK
~~~~~~~~
AS5
~~~~~~~~
PAD
~~~~~~~~
AS5
~~~~~~~~
FPGA
I never used the pad myself either. When Ztex shipped the fpga there was warning, that using the pad isn't recommended.
Maybe an experienced forum member here knows advise :/
April 29, 2012, 04:01:12 AM
BTW... one board run super and I've applied the heatsinks and AS5 in the same way.
Code:
001-0: ztex_ufm1_15y1-04A346343E-1: f=224.00MHz, errorRate=1.05%, maxErrorRate=1.89%, hashRate=221.7MH/s, submitted 10 new nonces, luckFactor=1.14
001-0: ztex_ufm1_15y1-04A346343E-2: f=220.00MHz, errorRate=0.10%, maxErrorRate=1.51%, hashRate=219.8MH/s, submitted 17 new nonces, luckFactor=1.11
001-0: ztex_ufm1_15y1-04A346343E-3: f=220.00MHz, errorRate=0.00%, maxErrorRate=0.00%, hashRate=220.0MH/s, submitted 15 new nonces, luckFactor=0.98
001-0: ztex_ufm1_15y1-04A346343E-4: f=212.00MHz, errorRate=0.02%, maxErrorRate=0.77%, hashRate=211.9MH/s, submitted 22 new nonces, luckFactor=1.02
001-0: ztex_ufm1_15y1-04A346343E-2: f=220.00MHz, errorRate=0.10%, maxErrorRate=1.51%, hashRate=219.8MH/s, submitted 17 new nonces, luckFactor=1.11
001-0: ztex_ufm1_15y1-04A346343E-3: f=220.00MHz, errorRate=0.00%, maxErrorRate=0.00%, hashRate=220.0MH/s, submitted 15 new nonces, luckFactor=0.98
001-0: ztex_ufm1_15y1-04A346343E-4: f=212.00MHz, errorRate=0.02%, maxErrorRate=0.77%, hashRate=211.9MH/s, submitted 22 new nonces, luckFactor=1.02
April 29, 2012, 03:57:19 AM
Did you use the thermal pad that came with the heatsink? Maybe this is the issue here.
No. Do I have to use the pad and thermal compond???
Something like this:
HEATSINK
~~~~~~~~
AS5
~~~~~~~~
PAD
~~~~~~~~
AS5
~~~~~~~~
FPGA
April 29, 2012, 03:54:54 AM
Now a test to prove my theory.
I've applied some new AS5 and scrachted it linear very slightly. Then I've put the heatsink and moved it around a little bit. With the same result: the heatsink touches only at the corners. Here are the photos:
What can I do???
I've applied some new AS5 and scrachted it linear very slightly. Then I've put the heatsink and moved it around a little bit. With the same result: the heatsink touches only at the corners. Here are the photos:
What can I do???
April 29, 2012, 03:49:43 AM
Did you use the thermal pad that came with the heatsink? Maybe this is the issue here.
April 29, 2012, 03:46:17 AM
I guess I've found the problem.
This is the of the worst Quad I have.
So I removed the heatsink of FPGA-4, because it's the one with the lowest frequency.
Here are the photos of the heatsink and the fpga:
Can you see it? The heatsink touches the chip only at the corners
This could be the heatsink or the chip. One of both is bent and not flat!!!
This is the of the worst Quad I have.
Code:
002-0: ztex_ufm1_15y1-04A3476278-1: f=200.00MHz, errorRate=0.87%, maxErrorRate=1.00%, hashRate=198.3MH/s, submitted 14 new nonces, luckFactor=0.82
002-0: ztex_ufm1_15y1-04A3476278-2: f=196.00MHz, errorRate=0.23%, maxErrorRate=0.55%, hashRate=195.5MH/s, submitted 16 new nonces, luckFactor=0.88
002-0: ztex_ufm1_15y1-04A3476278-3: f=196.00MHz, errorRate=0.00%, maxErrorRate=0.81%, hashRate=196.0MH/s, submitted 13 new nonces, luckFactor=0.83
002-0: ztex_ufm1_15y1-04A3476278-4: f=192.00MHz, errorRate=0.11%, maxErrorRate=0.50%, hashRate=191.8MH/s, submitted 10 new nonces, luckFactor=0.95
002-0: ztex_ufm1_15y1-04A3476278-2: f=196.00MHz, errorRate=0.23%, maxErrorRate=0.55%, hashRate=195.5MH/s, submitted 16 new nonces, luckFactor=0.88
002-0: ztex_ufm1_15y1-04A3476278-3: f=196.00MHz, errorRate=0.00%, maxErrorRate=0.81%, hashRate=196.0MH/s, submitted 13 new nonces, luckFactor=0.83
002-0: ztex_ufm1_15y1-04A3476278-4: f=192.00MHz, errorRate=0.11%, maxErrorRate=0.50%, hashRate=191.8MH/s, submitted 10 new nonces, luckFactor=0.95
So I removed the heatsink of FPGA-4, because it's the one with the lowest frequency.
Here are the photos of the heatsink and the fpga:
Can you see it? The heatsink touches the chip only at the corners
This could be the heatsink or the chip. One of both is bent and not flat!!!
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