FPGA Board 4x XC5VLX155T 300$

[eule]

http://www.ebay.de/itm/360661172756?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Seller is not me. I was interested in buying it, but can't afford to do so. Going by this info http://www.dinigroup.com/~mdini/Bitcoin_mhash_FPGA_guide_v1402.pdf ,  each chip should deliver ~180 MHash.
The seller has more of these boards but at a much higher price, one even with a loose chip. Too good to be true or probably broken? Listing says pulled from working equipment.
There are more cheap FPGA board to be found, e.g. http://www.ebay.de/itm/Xilinx-HW-S6-SP661-OPT1-1-board-/111092117484?pt=LH_DefaultDomain_0&hash=item19dd9b2fec , i think that's a Spartan 6 Board for 50$, couldn't find the part number at Xilinx though, so no way of knowing what exact chip is in there (unless someone of you knows or finds the number).

Your thoughts please.

_{If this link made you rich, tip me}

[TomKeddie]

I have a system made of 32 v5lx220 devices using the open source HDL.  These are nice because they're big enough to fit two cores with no hand optimisation.  I get about 250MH/s per fpga before the 1.2/1.5v power supply cuts out (these are reclaimed boards).

I also have a board with 4 V5LX155 on it - I haven't bothered with this board because I can only fit a single core - ie. 125MH/s without hand optimisation (which is beyond me).

To do something good with these board I think you'll need good FPGA skills.

*edit* also without a schematic it might be hard to get serial ports to the chips (or even jtag).

[goxed]

I have a system made of 32 v5lx220 devices using the open source HDL.  These are nice because they're big enough to fit two cores with no hand optimisation.  I get about 250MH/s per fpga before the 1.2/1.5v power supply cuts out (these are reclaimed boards).

I also have a board with 4 V5LX155 on it - I haven't bothered with this board because I can only fit a single core - ie. 125MH/s without hand optimisation (which is beyond me).

To do something good with these board I think you'll need good FPGA skills.

*edit* also without a schematic it might be hard to get serial ports to the chips (or even jtag).

Hey how do you make 2 cores communicate with the UART and the mining software? Any link to HDL code?

Thanks a lot in advance. I am trying to fit two cores into a Kintex-7 LX 325 device.

[eule]

Thanks for your thoughts Tom! So this board would have been very nice a few months ago. Still a better deal right now than one of those 2 BTC+ USB ASIC sticks (if you have the skill of course)... Seeing all the RAM made me think about scrypt or even scrypt+keccha (aka jane-scrypt) mining... Also to a noob like me it looked as if there was a JTAG header next to each FPGA. [nope, not next to them]

Any opinion about the Xilinx HW-S6-SP661 OPT1-1 in the second ebay link? I searched for hours but couldn't find any info about it, closest number i saw was the S6-SP601 which has one of those 200Mh SP6LX200 chips, made me think this might have the same CPU. 50$ would be a good deal for 200Mh i think.

The seller also had some Virtex6 and Kintex? (iirc) boards, unfortunately i couldn't determine if a chip was there or not, not to mention being unable to find any info about the boards... similar to this one but with installed heatsink:
http://www.ebay.de/itm/Xilinx-HW-V6-ML621-REV-A-VIRTEX-6-Development-board-/111080768394?pt=LH_DefaultDomain_0&hash=item19dcee038a

PS: Where to get cheap and used 32 chip boards? Not that i expect an answer...  

[TomKeddie]

I have a system made of 32 v5lx220 devices using the open source HDL.  These are nice because they're big enough to fit two cores with no hand optimisation.  I get about 250MH/s per fpga before the 1.2/1.5v power supply cuts out (these are reclaimed boards).

I also have a board with 4 V5LX155 on it - I haven't bothered with this board because I can only fit a single core - ie. 125MH/s without hand optimisation (which is beyond me).

To do something good with these board I think you'll need good FPGA skills.

*edit* also without a schematic it might be hard to get serial ports to the chips (or even jtag).

Hey how do you make 2 cores communicate with the UART and the mining software? Any link to HDL code?

Thanks a lot in advance. I am trying to fit two cores into a Kintex-7 LX 325 device.

Take a look at the OrphanGland stratix implementation project in the open source miner code.  they just split the problem space into n and have each core working part of the same share.  This way you don't complicate the s/w and h/w multiplexing multiple jobs on the same serial port.

[TomKeddie]

For any board you are interested in you need to try to route a design for the chip before buying.  This will give you an idea of what you will get out of it.  It won't tell you what clock rate you can achieve though, this depends too much on the power supply.

PS: Where to get cheap and used 32 chip boards? Not that i expect an answer...  

That's a really sad story.  In 2009 the co i work for was bought out and the v5 project we were working on was abandoned.  We junked most of the boards (like 20 or so, each with 4 chips).  Imagine mining with this system since 2010, man you could retire on that.  I've only been going since March, nothing remarkable, a coin a week or so.