cooling and more memory?

Any technical questions about the Epiphany chip and Parallella HW Platform.

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cooling and more memory?

Postby manukit » Tue Jul 30, 2013 6:51 pm

Hello, i wanted to ask you if the paralella board needs a cooling fan or thermal solution and how much is the maximun RAM that the board can use besides the original 1GB.

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Re: cooling and more memory?

Postby markrose » Wed Jul 31, 2013 3:59 am

The RAM is limited to 1 GB. Other parts of the 32 bit memory address space are used for the parallella cores, the FPGA, etc.

I've read elsewhere the Zync70x0 FPGA gets very hot if you fully utilize it. I'll probably stick a heatsink on that when mine arrives.
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Re: cooling and more memory?

Postby Gravis » Wed Jul 31, 2013 11:31 am

manukit wrote:Hello, i wanted to ask you if the paralella board needs a cooling fan or thermal solution

no, it does not need any heatsinks or fans.
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Re: cooling and more memory?

Postby FatherSuperior » Mon Mar 03, 2014 9:55 pm

It seems that the board needs a fan, based on the little not I found when the board arrived. There are a bunch of fans with heat-sinks for RPi on eBay. Any idea where I could connect the pins for the fan on the board or anywhere else?
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Re: cooling and more memory?

Postby 9600 » Tue Mar 04, 2014 4:48 pm

Gravis wrote:no, it does not need any heatsinks or fans.


Not great advice, Gravis.

I would strongly recommend that people attach the provided heatsink to the Zynq chip, as it does get quite hot. Furthermore it is suggested that a fan be used also if you plan to use the board with heavy workloads (running on the ARM cores and/or a heavily utilised PL).

Cheers,

Andrew
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Re: cooling and more memory?

Postby 9600 » Tue Mar 04, 2014 4:55 pm

FatherSuperior wrote:It seems that the board needs a fan, based on the little not I found when the board arrived. There are a bunch of fans with heat-sinks for RPi on eBay. Any idea where I could connect the pins for the fan on the board or anywhere else?


If you bridge J15 on the board this will route 5vdc to the adjacent mounting hole pad, with the other 3x mounting hole pads being at ground, so you can take a supply from the first and one of the latter three. If using those holes to mount the board in an enclosure you obviously need to make sure that the fittings, e.g. hex stand-offs and/or enclosure, are non-conductive — so that you don't short out the 5v rail.

Cheers,

Andrew
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Re: cooling and more memory?

Postby mranderso » Wed Mar 05, 2014 1:48 am

Here is my experience.

I ordered the 8 board cluster. Arrive some time last week.

After spending a great deal of time writing 8 disks, I tried booting
up each board one at a time, straight out of the box. Fearful of
USB hubs at this point, I used a serial connection alone (no USB,
no HDMI).

One of the boards failed ./test.sh. :( It was one of the first
boards I tried. I continued with the rest and they all passed the
one run of ./test.sh. I returned to the first board and it passed.
And then tried again and it failed. Passed test intermittently, so
I wrote a script to run test.sh 100 times and record results.

So I installed heat sinks on 7 of the boards. ( One of the heatsinks
lost the backing in transit and was stuck to the plastic envelope
around the board in the box. Enough of the plastic stuck to the
adhesive when I pulled it free that I decided to not use it. Ordered
some thermal adhesive to attach later).

5 of the boards, including the one with no heat sink ran thru the
set of 100 test twice with no mismatch ERROR.

3 of the boards with heat sinks had double digit mismatch ERRORs.

I didn't have any computer fans around, so I found a 9 inch 60W
floor fan to create more than a little air flow.

With the air flow, the 3 troublesome boards all ran test.sh 100
times without ERRORs.

Will have to find a less obnoixous fan arrangement, but not sure
just yet how much air I need to move.

So you might get lucky and have success with not heat sink or fan,
but it appears to be the luck of the draw. I'm going to using multiple
power strips anyways, so I plan to power fans off AC.
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Re: cooling and more memory?

Postby ubii » Wed Mar 05, 2014 6:42 am

mranderso,

If you want to monitor the temperature of the Zynq chip, I posted a simple bash script in the thread below, which will display the temperature in both Celsius and Fahrenheit.

viewtopic.php?f=23&t=930&p=6242#p6242
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Re: cooling and more memory?

Postby Sundance » Wed Mar 05, 2014 12:04 pm

Mark - and all Software Engineers ;)

Another story from the REAL life of Embedded Signal Processing that I have been trying doing for the past almost three decades... :shock:

After years of development we finally shipped lots of "Production Box's" to our lucky (and now hairless Customer :!: ) - and the Software Engineer that was allocated by our Customer as "Project Manager" got 10x of them running in a test setup in his office. The following morning he reported that 4 our of 10 had failed. Well.. - not good news. We could simply not understand. Suggested a few things, like measuring the power-rails, connectors, fan, temperature of the DSP, etc. - Asked him to repeat the test.

Next day 5 out of 10 had failed, but not all the same that failed the day before... - and had to get on my push-bike to visit them. I came to the Customers office and to my shock and horror I discovered that the Software Engineer had taken the lid of the 'Box', so the effectiveness of the fan was effectively 50%! When I asked WHY the lids was OFF the box, then he said it was easier to measure the temperature and see what was going on. :roll:

So...

The Parallella NEEDS to have the Heat-sink fitted and, depending on how warm your office is, will ALSO need a FAN!!


- and we need you "Software Engineers", as us "Hardware Engineers" are lost with you!
Flemming Christensen
Mobile: +44 7 850 911 417;
Email: Flemming.C@Sundance.com
Skype: Flemming_Sundance
Company Home Page: http://www.sundance.com
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Re: cooling and more memory?

Postby aolofsson » Wed Mar 05, 2014 1:10 pm

mranderso wrote: With the air flow, the 3 troublesome boards all ran test.sh 100
times without ERRORs.

Will have to find a less obnoixous fan arrangement, but not sure
just yet how much air I need to move.

So you might get lucky and have success with not heat sink or fan,
but it appears to be the luck of the draw. I'm going to using multiple
power strips anyways, so I plan to power fans off AC.


Great to hear that you received your board and that you are working with them!! I had a panic attack as I started to read your post..but reading further it does seem like you have your cluster up and running.

The need for a fan is a really unfortuate reality. The board consumes 5 Watts, which is simply too much for such a small board without any kind of custom fitted heatsink or fan. (I am sure Sundance would concur). We would have loved to ship a fan with every board to make things easier, but with us losing significant money on every one of these Kickstarter boards , this was not practical.

The good news (if there is any) is that the amount of airflow needed is really minimal so almost any fan will do. As shodruk and syoyo showed in their demos, a regular desktop fan will do as well. Here are links to a few example fans that we have used in the past.

Tiny fan for one board:
http://www.digikey.com/product-detail/e ... ND/2757803

Large cluster fan:
http://www.newegg.com/Product/Product.a ... 6835103192

Desktop fan:
http://amzn.com/B000QR6VXW

Andreas
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