You can actually fit 1.5 engines on a chip, assuming an engine is a full 128 rounds of SHA-256 (that's 128 because you need to do it twice to get the final hash that Bitcoin expects). One full engine, at 128 rounds, and a second half-engine, at 64 rounds, with a mux in front to switch between processing new data and finishing old data.

I've considered doing that for my C120, which would fit one full engine in 80K LEs, and the half-engine in 40K (if I'm lucky). Or just get my hands on a C150 and try desperately to cram two full engines on it

Without having an actual Spartan-6 LX150 board on hand, I ran my design through ISE quickly. This showed that the LUT consumption is indeed similar to Altera's, so there does not appear to be any area improvements by using a Xilinx device over Altera.

What I do not know, however, is how fast Spartan-6 LUTs operate compared to Altera's, for apples-to-apples speed grades. If they run faster, it would indeed be possible to get more bang for your LUT. I get 80MHz in my design, resulting in 80MHash/s burning 80K LUTs. The Cyclone4-150 or Spartan6 LX150 may fit two full hashing pipelines (128 SHA-256 rounds per full hashing pipeline). This would double their performance. The Cyclone4-150 achieving 160MHash/s. If the Spartan6 is faster, it could possibly achieve >200MHash/s as you've reported.

You could get faster speed grades, but those are typically a bit more expensive. I haven't calculated whether a fast speed grade would balance out the cost for its improved hashing speeds.

For which platform? The PICO EX-300 platform? You're probably talking about a platform with Spartan-6's on it, because those do indeed carry four 4-LUTs per slice, with the LX150 totaling ~150k 4-LUTs.


I develop on a C120, and I have different designs, some of which are indeed pipelined. The pipelined designs get 1Mash/s per 1K LUTs.

Perhaps the Xilinx devices can pack far more bang-per-LUT than Altera's for SHA-256 designs? I shall certainly investigate. Again, thank you for sharing your numbers.

Hello cypherf0x! Good to see a fellow FPGA developer on the forums  

I'm a bit curious about your numbers. Working with an Altera Cyclone3 and Cyclone4, which are the brothers of the Xilinx Spartan series, I've only ever seen 1MHash/s per 1K LUTs. The chips you describe have the equivalent of 75K LUTs (Xilinx has a funky design), which means no more than 75MHash/s. If you are indeed getting >200MHash/s out of a single Spartan 75K, that would be quite wonderful!

Anyway, thank you for posting your findings and, even if you don't post anything more about your research, it's always good to have a new, knowledgeable member on the forums.

I can confirm this. Same problem on my Ubuntu 11.04 (64-bit) machines. I also heard mention of it on an IRC chat. Apparently you need to edit xorg.conf and move the second screen over so that your mouse can't get to it. I haven't tried it yet since my machines are headless.

EDIT: Well I can't find any options in man xorg.conf to "move the screen over" which is what I remember someone suggesting. Perhaps the extra Screens can just be removed?

Oh man, I forgot about those. Yeah, they're terrible! I took them off (which was easy).

And yes, you're right about the case connectors. Those wouldn't fit a long video card. If you don't have a case, though, you don't need those connectors, so not a huge deal.

But...
Yeah, that's a nice board  . It's a shame the last slot is unusable if you have a case.

But, as I said, I probably wouldn't use a case again. I'd just buy a wire shelf from the hardware store, cardboard, and twisty ties. Heck, you could even use extenders and dangle video cards from an upper shelf with the mobo below it

Thanks for commenting on my post!

My total hashing power is 3500MH/s right now, but 720MH/s of that is from my original mining rig (cheap 5970 with existing hardware). So I gained an extra 2700MH/s from these new slaves.

$2600 is the total cost after shipping and taxes. The taxes and shipping account for the $300 difference in your estimate

That's about the $1 per MH/s figure I was aiming for, so I'm happy with it.

I'll actually get a little bit of that money back from cashback and bitcoinbonus, rebates, and hopefully selling the free Steam codes that came with the video cards.

I finally finished piecing together and tweaking my three new mining rigs.  Here's to hoping they can fund my FPGA Mining research!

I will disclose my adventures and learnings here, for the benefit of fellow Bitcoiners.

Original Setup (per rig)
* Video Cards: 3x Sapphire 5850
* Motherboard: Assrock 890GX Extreme4
* CPU: AMD Sempron 140
* Memory: 1GB Kingston DDR3 1066 (PC3 8500)
* PSU: Rosewill RBR1000-M 1000W
* 16GB flash drive
* A mystery case ...

Software
Ubuntu 11.04 64-bit - Catalyst 11.4, SDK 2.4
Phoenix 1.4 with phatk kernel

Stats
Overclocking: 800/285
Hashing: 313MHash/s per card, 939MHash/s total
Temps: 68C, 66C, and 61C

Things That Went Well
---The motherboard is quite nice for its price. On-board power, reset, and Clear CMOS buttons. On-board GPU. Three slots for graphics cards, and an extra PCI-e 1x for future expansion.

---NewEgg's shipping 

---The MtGox price jumped to ~$9 as my parts were arriving. It's back down to $7 now, but that's still better than the numbers I did my cost analysis on initially.


Things That Went Okay :/
---The CPU and 1GB of RAM runs fine, but installing software through the GUI can sometimes throw stuff into cache and make stuff a bit sluggish. However, once you have everything installed, mining works just fine.

---The case I got is nice. 140mm on top, 120mm in front and back, and 2x120mm on the side over the GPUs. Pretty cheap too.


Things That Were Difficult 
---I wanted to use the front USB plugs on the case, and so plugged that cable in. One loud screeching noise from the video cards later I realized the USB plugs are too close to the bottom video card This caused the cable to hit the fan. No damage done, but I have to use the plugs in the back.

---Initially the middle card was running very hot. >80C, sometimes touching 90C. I built my rigs one by one, so I could test them out and apply updates to the design on the next two. So for the second rig I shoved the PSU in the CD/DVD drive bays. I had to bend the metal a bit, but it fit.

For the second rig I also used some bits of plastic to push the video cards apart. On this motherboard they are right next to each other with very little room. That seemed to help a little; allows more air to get to the GPU fans.

And finally I also experimented with memory underclocking. From stock 1000MHz down to 285MHz. Runs stable, and that final tweak seems to be what got me my final numbers. 68C, 66C, and 61C.

---Wiring was a huge pain in the butt. I have a bunch of velcro strips that I use to tie wiring together, and those were great. I keep all the paths for airflow wide open, but everything else is jammed full of wires.

---The biggest wild-card in my entire setup was the PSU. It had great user reviews, it was cheap, and had plenty of power. Only problem was, it had four separate 12V rails. I figured, if I was careful, I could use one of each GPU, and one for the motherboard and fans.

Long story short, it worked out just fine and the machines are running fine. But it was nerve-racking worrying about whether the rails could handle everything. The motherboard was especially worrying, because it supplies up to 75W through the PCI-e ports. 75 * 3 = 225W, or 18.75A. On a 20A rail ...

Also, the PSU had modular cables, but because I was so worried about power balancing, I put the case fans on the two 30A rails. This required attaching two of the PSU cables, and added clutter. What a mess!

---Another thing that ended up being difficult was my purchase from TigerDirect. Apparently they don't like money and decided I had to wait all weekend for them to verify my CC. This is despite me ordering from them a few times before. They called me, but when I called back they were closed. Then when I called Monday they said everything was fine ... so, I appreciate the waste of my time. Also, my items got back-ordered. Didn't get here until Friday (ordered the weekend before, 2day shipping).

NewEgg, on the other hand, had that stuff out and in my hands the second I pushed "Confirm." Well ... not that fast, but I've always loved NewEgg's speed. Also, they don't seem to sell back-ordered items like TigerDirect.


Things That Went Poorly
--- I initially chose to use 16GB flash drives as the hard drives for all these machines. I figured they would use less power, generate less heat, and not use any space inside the case (better airflow). I mean, Live Linux CDs run just fine off flash drives ... right? ... Well, after building the first rig, it felt like I had taken a step back in time to the 90s. With only 1GB of RAM, stuff was getting thrown into cache a lot. Guess where cache is? Yup, it's on the flash drive.

It didn't make a difference to mining, but it made installation take hours. It also meant longer boot-up times, which would exaggerate any downtime.

So I grabbed 3 of my old SATA drives and used those instead. Works great!

--- The on-board GPU worked fine for the first mining rig. The other two, however, refuse to use it. They can't even see it. It's not a big deal, but it's nice to have in case the cards lock-up and to keep GUI load off them. Still not sure why this is ... (the option to use on-board doesn't even show up in the BIOS).


Things I Would Change 
---In retrospect I would have dropped the case and bought a more expensive, single-rail, PSU. I wanted the case, because it was so cheap (like $50), and would provide easy mounting for fans and good airflow control. Well, I'll bet I could have bought a big, cheap shelf from the hardware store; mounted all the machines to it, and twisty tied all the fans around it. That would also have made wiring up the equipment easier.

Without a case, I would also have gotten a different motherboard with 4 slot capability. I didn't do that for this setup, because the 4th slot was at the very edge of the motherboard. That wouldn't fit the two-slot 5850s (fan on second slot). Without a case, though, that wouldn't have been an issue. Regardless, with a PCI-e 1x adapter I can get a 4th card on this motherboard.


Other Factors
---The first night of running the machines, they were all in my living room with the windows shut. I woke up to an oven, and decided to fry some eggs on the cases. While it was neat to cook breakfast on my mining rigs, the clean up was a tad messy, and ultimately I wanted the apartment to be less than sweltering. Also, I used the last of my green peppers so I need to buy some more.

I ended up moving the machines next to a window. A big appliance fan will be purchased later to push all the heat out the window. Like a Pro.

---The last ordeal of my story is something I had completely forgotten to take into account. Circuit breakers. Like most typical homes, my apartment has several circuits for all the 120V outlets, each circuit with a 20A or 15A fuse. These fuses blow if the instantaneous current exceeds 20A, or if the average current exceeds ~17A. That's about 1800W. The power strips I use are also rated for 1800W. If each rig draws 1000W at max, that's well over what my apartment can handle on a single circuit.

The 5850s draw ~180W each, which is 540W total. +100 for the rest of the computer and you have 640W. That's 1920W for all three machines.

I spent thirty minutes mapping out my entire apartment's circuit-to-outlet chart. With many thanks to the engineer who put this place together, the majority of the apartment's outlets are on a single circuit. Yay! So much fun! The rest are sporadic, with no logic to their placement. Also, I have no idea where two of the circuits are. They aren't hooked up to any outlets or lights ...

For now, I've got all 3 rigs running on one of the oddly placed circuits, which has nothing else on it. So far so good. I have one more nearby empty circuit I can use if things go awry.

It's all a huge pain. Hopefully something comes of my FPGA tinkering and I can replace these rigs with clean and efficient FPGA mining. 

Closing Thoughts
Worth it? Yes! Mostly because it was like Christmas Day getting all those shipments, tearing open the boxes, and piecing everything together. It's also a total nerd fest, and warms my geeky heart to have a mini-datacenter churning away 

Will it make me rich? Probably not. I'll be happy to break even and walk away with the experience. If it does churn out some cash, I'll pump that into my FPGA mining research.

By increasing the core voltage to 1.23V. That allows the card to run at higher speeds, but it carries far more risk than overclocking. As pointed out, simply increasing the clock speed will not damage the GPU in any way, except through excessive heat (1). Overvolting, on the other hand, can physically damage the GPU. I've heard the limit for these GPUs is 1.25V.

(1) The GPUs are actually rated for very high temps. Over 100C. And the card will shut them down if they get too hot anyway.

Is there a command-line driven ATI OverDrive Utility that allows properly adjusting the memory clock? aticonfig won't let me set the memory clock lower than the default 1000. So far I have used AMDOverdriveCtrl to set everything up, and it's great, but it requires a GUI. I want to be able to SSH into the rigs and set everything up, or even script stuff.

EDIT: Oh, looks like AMDOverdriveCtrl lets you run a "batch-mode" and specify a profile. That's pretty decent for scripting. Not ideal, but a good work around.

Wow ... umm ... I downloaded the MP3 in the OP to listen to some Bitcoin stuff. Then some poor woman called in to talk about the Osama news, and the hosts just ... ripped her apart. They were rude and outright vicious. They barely listened to her, cut her off all the time, and even started yelling. It got so bad that at the end they started coming up with hypothetical situations where they were going to kill her or steal all her money!?!    They were obviously in jest, of course, but that seems like an inappropriate thing to say to someone who calls into your show.

Is this just Fox News with an opposite political compass?

Remind me to never listen to that show again.

Stop enticing me with gambling games! 

So tempting ...

Oh, it's depleted. Thank goodness.

I gave it a shot.

It was a slow start. I didn't know how to run for the longest time, so it was excruciating to get anywhere. Also, the camera is a pain in the arse. And the constant "You can't move there" dialogs (even though I disabled them). But after I got a few BTM from the statues I played a few of the games and ... it was pretty fun! So, overall, a neat little thing. Worth trying if you want to just relax for a few hours after work.

Only major problem now, is, I withdrew 0.13 BTC last night before logging off. The transaction showed up on my wallet, but 10 hours later at it has no confirmations at all. Guess it's really low priority.

I ran this new kernel against stock poclbm using my 5970. Although the MHash/s was +10 for the modified kernel, it ended up getting less accepted shares in the long run (several hours). That may just be terrible luck, but I tried it twice; once under Windows, and then under Ubuntu. Both times for several hours. Both times with the same results (stock poclbm with more accepted shares).




I have not tried swapping which core the respective kernels were running on, but it's been enough downtime for me today 

I'm selling 8 copies of Total War: SHOGUN 2, Steam Digital Download codes, for 7 BTC each.

Retail: $49.99 USD, 8.93 BTC (@5.6USD/BTC)

The codes came on these cards:


They are untouched:


You'll need Steam installed to redeem the code. It's just a code, so no Steam trading needed or anything like that. I'll just scratch off the card and send you the code.

PM me to start trade.


This is my first trade , but I've been floating around the forums helping and posting for a little while now. I registered with bitcoin-otc: fpgaminer, and I'm lurking on #bitcoin-otc if you want to do the trade there.

Thank You!

Here's some verification:



-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Total War: SHOGUN 2 Digital Download (Steam) for 7 BTC
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (MingW32)
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=e4DW
-----END PGP SIGNATURE-----

EDIT: I also have 1 copy of Dirt 2 (Steam download code from a card), and one copy of Portal 1 available as a gift on my Steam account. Feel free to PM me offers for those.
EDIT2: My Steam Profile (created 2004), with more GPG goodness.

Yes.

The stores don't do it; it's the employees who skim or steal information. So it's the employee that would get in trouble, not the store. I've personally had my CC info stolen by a store employee before. 

And it can happen at any store you shop at. Either the employee is handling the card directly and memorizes the information, swipes it below the counter, or installs a skimmer on the reader you swipe through yourself. And as pointed out, gas stations will install the skimmers right inside the machine.

Luckily U.S. credit cards are federally protected past $50, and my bank is personally happy to reverse all charges with no fee in the event of theft.

Hmm ... did you run it locally or on a server? It might need to be run on an actual webserver, but I don't remember for sure. Google Chrome in particular gets cranky when JavaScript is run off the filesystem.

But you don't want it plugged in when you're handling it 

Just wait until one of the spiders falls into your GPU fan...

Yay!

I got my 5850 running at 900MHz@1.150V. Finally.  It has been stable during the day (before it crashed at 900MHz). I might try cranking it up more tomorrow.

I like how my purchase is actually increasing in value over time 

To be technical: only if the filing cabinet and motherboard share the same ground. It's usually good enough, since most everything finds its way to Earth ground eventually, but you should do your best to ground to whatever the device is grounded to.