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Title: Releasing my FPGA board files Post by: newMeat1 on June 27, 2011, 03:46:08 AM http://i1116.photobucket.com/albums/k575/newMeat1/th_PCB048.jpg
After a lot of thought, I've decided to release my FPGA files. I've put a lot of time and effort into designing a minimum-cost FPGA board. I've been through 2 prototype cycles, but this stuff is expensive! On my student budget, I can't afford to spend any more on a project that may or may not pan out. When I burned out my last Cyclone IV, I was like, "I'm done!" The design is 98% there, I believe. Thanks to fpgaminer for lots of advice. Here's a link where you can download a zipped folder. It contains pictures, a Bill of Materials with cost breakdown and suppliers, a circuit board layout, and links to all of the Altera documentation I've been using. http://www.filedropper.com/pcbtoupload62611 (http://www.filedropper.com/pcbtoupload62611) You will need to download expressPCB's free CAD software to view the board layout. I hope that knowledgeable people with deep pockets can take this project and finish it. GPU mining is way too wasteful. There are probably still bugs in this design. I used a Cyclone IV EP4CE115F23C8N FPGA. It offers good performance for a decent price. We have already hit 80 Mhash/s with it, with no cooling other than a passive heat sink. The heat is the limiting factor. With better cooling, we'll be able to add a second core and run it faster. I'm thinking ~140 Mhash/s. As you can see, the board is very small. It would be very cool to make a cast aluminum box for it and fill the box up with mineral oil. That would give 100% reliable, cheap, quiet cooling. This guy may be able to hook one up: http://forum.bitcoin.org/index.php?topic=20404.0 (http://forum.bitcoin.org/index.php?topic=20404.0) Feel free to send a few bones my way if you like the project! Title: Re: Releasing my FPGA board files Post by: kokjo on June 27, 2011, 07:02:04 AM nice +1
Title: Re: Releasing my FPGA board files Post by: O_Shovah on June 27, 2011, 01:47:46 PM Very nice project
Thank you very much for sharing you experience. Did you make an solder the PCB yourself ? How many layers did you use ? regards Jens Title: Re: Releasing my FPGA board files Post by: newMeat1 on June 27, 2011, 07:39:20 PM I'm going to merge this thread with the Official Open Source FPGA Miner thread now...
http://forum.bitcoin.org/index.php?topic=9047.0 (http://forum.bitcoin.org/index.php?topic=9047.0) To answer your questions, Jens: It's a 2-layer board. It was challenging to fit everything on 2 layers but I think it will work. The boards are made by expressPCB, they cost about $14 ea. I do the soldering myself. I ruined the first batch, but since then it's gone pretty smooth. It would be great to get a few new pairs of eyes to look everything over. If we can raise ~$450, I'll give it another shot. Title: Re: Releasing my FPGA board files Post by: teknohog on June 27, 2011, 10:06:47 PM It would be very cool to make a cast aluminum box for it and fill the box up with mineral oil. That would give 100% reliable, cheap, quiet cooling. I think mineral oil would be overkill for 4.4 watts. For starters, you would need fancy sealing to get the wires through. I'm sure there are simpler ways of mating the chip with the heatsink. (This is probably off-topic, but I've given a lot of though to quiet cooling. For starters, you can buy a passive-cooled HD5770, that's over 100 W without mineral oil. A case fan is needed, but a 12-cm one at 7 V will do without making any discernible sound. Similar fans are found in some aftermarket coolers for HD5870s. Then there are passive-cooled power supplies, at least up to 460 W which powers two 5870s nicely. Plus, obviously, fanless CPUs.) That said, I agree that GPUs are wasteful, and I appreciate your work with FPGAs. But to me the problem is simply power consumption, because the noise problem has already been solved. |
