Doesn't it seem "natural" that if there is an S6 it will be using S5 chips? That's pretty much their style for the previous miners they produced e.g. S1/S2, S3/S4).

While Bitmain doesn't fab their own chips, there's usually a significant cost to step from 28nm to another process geometry. New rules, design tools, and such make it resemble a "retooling" even if it's more like engineering design and software changes. Miner manufacturers have to decide if they want to make that "investment".

This is the classic "It isn't ROI unless it's ROI in Bitcoin". Since Bitcoin price has floundered in the last 6 months then the whole argument dissolves. Personally I calculate based on fiat. I don't see a resolution to the different views of ROI anytime soon, and the volatile Bitcoin price won't help.

@biodom: Thanks very much for the clue about the drop-down selection box for the SP20 firmware version. I didn't notice the "down arrow" and assumed there was only one. I see several other TEST versions now.

@zvi: Thanks for elaborating on the 2.6.7 and 2.6.14 versions of the firmware. I's really nice to have that kind of insight. I also appreciate that Spndoolies has a a true technical guy on here from time to time, and not strictly a "corporate mouthpiece" to dispense the company line.

While I only have about 10 hours on the 2.6.14 firmware it's vastly more useful than 2.6.1. I haven't been able to coax the fan below 10 yet, even when using auto, I think I'll be able to make good progress with this.

Thanks again folks, and Spondoolies!

I'll bet on an increase:

+1.8%

I recently received a used SP20. I know that it works, and can hash. When I received it, it had Firmware 2.5.61 installed. Virtually everything I have seen posted here for a recent version is 2.6.x. So I went down the route of "Upgrading the firmware". I went and let it choose the "latest firmware", and the result appears to be 2.6.1. I am virtually certain that many folks have 2.6.7 or possibly 2.6.14? I then tried the auto update again, and it says "I am current with the latest". I then looked into a "Manual Selection", and said that 2.5.12 was the only one I could choose from. That just didn't look right, so I decided to seek advice here before I try and advance beyond 2.6.1.

1) I am truly confused by the firmware version numbering scheme.

2) How do I get beyond 2.6.1 to something that's got better control of the fan?

If there is a discussion of this somewhere in the past 500 pages, please point me at it.

Thanks very much!!!

There are a couple of other SP20 threads with a variety of options for fan noise reduction. One that seemed pretty simple and novel is to rotate the fan 180 degrees to reverse the airflow through the SP20. The author claims that it reduced the noise and actually improved the temperatures within the box. I am pretty sure he was "downclocked" so it might not be wise if you are pushing the box to it's maximum speed. No need for wire fiddling, or anything that can't be reversed if need be. It's also worth checking the PCIe power connections to make sure they aren't getting too hot if you reverse the airflow through the box.

On the top cover of the SP20, or at least the one's I have seen, there is a set of carefully placed and threaded holes drilled. They don't just look like a fabrication "mistake". Does anyone know what those are for?

Besides, this is the speculation forum......

I thought the original spec from Molex for the pins in the PCIe socket was the same as the original ATX socket, and I thought that was 5 amps. Does anybody have a more accurate recollection or specification on that? At 240W, that's 20 amps split across 3 pins, and also 3 wires. That's just shy of 7 amps per pin/wire, assuming all is well balanced.

While the rig setup is impressive, even more striking is that your GF is interested in working on this! That to me is probably the most valuable thing you have going for you..... 

While I won't comment on the financial sense of the hosting offer, I think it's utter nonsense to consider this "centralization" of the Bitcoin network in any way. Unless I misunderstand the offer, the hosting facility exerts zero control on what pool,  or even what coin you try and mine. The offer is for space, electricity, cooling, and Internet access. This is distinctly different than cloud mining, or any of the mega farms created by the various ASIC companies.

Looks to me like suchmoon won't be paying out anything at this time. I think there's only one member that has a chance at this, and that's if things slow down some in the next 36 hours. If this is actually variance, then we shouldn't see another big increase after this upcoming one in a day or so. While I am no math wizard this seems like a real increase, not just statistical jitter.

While I would be absolutely stunned if you actually got anything besides a PDF confirmation, please report back on your outcome. I hope you are able to recover some of what you paid, since I expect this is a full on fraud. Sorry to be so negative........

Thanks, I appreciate the candor. I also appreciate the support offered on this forum.

I have found and examined the "SP20 Jackson Quick Start Guide". At the tail end of that 9 page document there is a reference to "SP20 Jackson User Guide" for further details. I have been unable to find the "SP20 User Guide" anywhere. Does this document exist, and if so where?  Is the "SP3x User Guide" useful at all for the SP20? Sorry if this is an silly  question, but I couldn't find anything relevant here.

Is there anything more descriptive than a Git repository URL? When you go there, you are confronted with 8 "things" that I assume are kinda like directories. When you dive into them, there are bits of code and stuff. Wouldn't it make more sense to give folks guidance  on how to achieve the desired goal using settings in the GUI? Am I just being too dense on this?

One items of note. The original post suggested that you are concerned about a timeframe of 1-2 years, I have yet a single example of a miner that has remained profitable to run for one year, much less two. Maybe that will all change in 2015, but I would be reluctant to think about more than 6-9 months for your SP35. This isn't a reflection on the specific hardware choice, just the nature of mining in general.

This is also where your cost minimization come in. Everything I have read indicates that the last 200GH area really pretty expensive to obtain in terms of power cost. There are multiple SP20 threads, even one that includes efficiency plotted again hashrate. The higher the speed, the higher the $$$/GH.

One minor quibble with "pre-orders". Didn't Bitmain advertise and take pre-orders for a Scrypt miner named the L1? As I understand they later canceled the product and never shipped any. While I expect that Bitmain didn't just run off with the pre-order money, I don't know how they made the customers "whole". Did they refund, or just issue "credits/coupons"? Either way folks had some opportunity cost with "dead" money, along with disappointment.