So SHA256 rental profitability is 9% over straight BTC.

Any ideas why this has suddenly ticked up? Not that I'm complaining ;-)

I think so. I started mining on slush for the first time several days ago. The expected 33% off offer appeared in my dashboard around 3 days later.

But I haven't tried to buy a Trezor with the discount yet. The recent BTC price slide of 15% in a week has given me pause...

Does anyone know how long the 33% discount is good for once it appears in the dashboard?

If you're looking for a new pool, check out Suchmoon's profitability thread:

https://bitcointalk.org/index.php?topic=514242.0

I ended up moving to NiceHash for scrypt mining after having a good experience with them during the Paycoin excitement. I didn't mine Paycoin, but made a lot of profit renting to those that did.

You might want to consider is the NiceHash/WestHash rental pool. During the recent Paycoin mining craze, NiceHash rental rates for SHA256 were as much as 8 times what you could mine with a standard Bitcoin pool. That's over now so the NiceHash rates are down to normal.

That being said, if there's another SHA256 pump and dump you can capture that by configuring NiceHash (or WestHash for the US) as your primary pool, but specify the minimum profitability that you're willing to accept. If NiceHash rental rates are equal to or above your specified profitability, then your rig will mine on it. If rentals are below your specified profitability, the pool appears dead and fails over to your next pool.

I've got WestHash configured with a profitability slightly higher than the normal bitcoin mining rate. Note that the profitability will change as the difficulty goes up.

Here's a partial copy of the configuration I'm using. Note that the "xnsub" means that extra nonce subscribe is on (which is supported by my miner):

This is no longer the case. Since those news reports, BTC Guild has indicated that they are not closing.

See this post on November 3, 2014 from the news feed on their site (partial quote):


BTC-Guild is a nice pool. I've mined with them in the past. Currently I'm on Antpool (mostly).

I'm interested in a Mac OS X version too.

My SP20 went non-responding yesterday after I added a couple of pools. The web admin GUI never came back after submitting the change, and I could not ssh into the device. It responded to pings, but that was it.

I power cycled the unit and attempted further edits to the pool list. It seemed to work for a little while, then the SP20 hung again.

Operating on a guess that maybe I had specified too many pools, I rebooted again so that I could remove some. Once I saw pings responding, I quickly fired up the web admin GUI and stopped the miner. This allowed me to get back to the pool list and remove a few. Since doing that, the SP20 has run reliably again.

Is there a known problem with too many pools? I had 9 pools specified at the time that the machine went non-responding. I know that's a stupid large number of pools, but I've just been moving disused pools to the bottom of the list with the thinking that if I needed them again, I could just change the order.

If the miner craps out after too many pools are defined, then the UI should probably limit the number that you can specify.

Note that this was with the v2.5.52 firmware.

I was skeptical about this offer from the beginning. Scrypt ASIC hardware is going nowhere fast.

But the fact that lifeforcepools has taken this long to respond to people's reasonable concerns over lack of information, plus the fact that (s)he's attempted to censor Suchmoon tells me to steer clear of this deal.

I'm "unwatching" this thread now...

Honestly I don't see the S5 making that big a difference. It really is too late when you compare it against the competition. Now that we know the S5 specs and price, it doesn't seem all that compelling.

For example, if I'm reading it right the S5 has no DC/DC converters which means that programable over or under clocking is out of the question for most users with standard power supplies. Also, it sounds like if there's a single ASIC failure in the chain, the whole chain falls over.

While all of this adds up to cheaper construction and better profits for Bitmain, it means the S5 is less flexible and likely has lower resale value potential than the competitors like the SP20. If you can't effectively under clock an S5, then what value will it have a few months from now?

Add in the fact that the free review models of SP20's have resulted in enormous PR on this forum. Those SP marketing folks really know how to effectively schmooze. Bitmain's PR and communication skills just don't compare.

Sure, some people will buy the S5. People like Bitmain and they like shiny new things, and they will buy it without doing their homework.

But it's not going to be a game changer for the next (or any) difficulty adjustment.

I'd be more worried that Spondoolies reduces the SP20 price again. If they knocked off another $200 (unlikely, but who knows), and if they could build them fast enough, they might move enough units to propel the difficulty again.

Hell, I'd probably buy more and have no idea where I'd put them (they are loud!)

If the Guldencoin devs wanted to avoid multipool shenanigans, why did they pick the Scrypt algorithm? Why not just fork to some ASIC/multipool resistant algorithm and fade into obscurity?

Can you say "Vertcoin"?

Sounds like I missed out on titcoin. Damn!

Well at least I got in on nicehash rentals at an insane rate for a few days. That's probably worth a pair of titcoins...

I've got free power in a data center, so I'm interested in getting the most out of my SP20. Noise and power use are not a concern.

With the stock settings I get about 1.675 GHs out of the unit. Unfortunately I'm not having much luck overclocking.

What I did was take my stock max voltage of 0.75 and increased by 0.01 then waited an hour for things to settle down. At 0.76 I got a very slight increase from 1.675 to 1.685, but any attempt to increase beyond that resulted in less than the original hash rate.

I didn't notice any obvious differences in the ASIC temperatures. Although since the current GUI just shows a snapshot of the current temperature, it's kind of difficult to get a sense of temperature trends. That is, if the blade is ramping up then hits the max temp, it will back down, but you can't really see that without historical temperature info.

Anyway, after searching around some more it sounds like maybe my unit was already hitting its maximum temperature on some blades and backing down. So I reverted my max voltage to the original 0.75, then turned up the fan to 90. Just increasing the fan resulted in about the same hash rate increase as bumping up to 0.76.

I think what's going on is that some of my blades are hitting the max temp and backing down, with the original manufacturer's settings. In fact I can see in the hash rate graph that it spikes up near 1.7 GHs then backs down periodically. It may well be that I simply cannot push it any further without additional cooling.

Here's a snapshot of my current ASIC stats:


Note that three are at 120c. They appear as yellow in the web GUI. My guess is that these are the ones that are bumping up to the 125c limit and backing down, but without historical data I can't be sure. Maybe there's a log event when an ASIC backs off? If so, I don't know what to look for in the event log.

I guess that I can try setting the fan to 100. Noise in the data center is not a problem. But with cold air blowing directly on the front of the unit (measured as 20 °C on the SP20 Temp Front sensor), it's somewhat disconcerting that I'm seeing the ASICs overheating at stock settings.

Any suggestions on how I can maximize the hash rate from this unit would be appreciated.

Also, I should note that I've seen at least one case where cgminer restarted, apparently on its own. It happened last night around 1 AM, according to the dashboard's CGMiner Uptime value. The main unit itself did not reboot, just cgminer.

I looked through the event log but could not find an event corresponding with the cgminer restart. Although it's kind of hard to deal with the event log because it's flooded with "DC2DC ASIC WARNING" entries for blades 2 and 3.

What causes the cgminer to reboot? Is that normal?

Thanks for the ASIC stats info. That's helpful. Maybe it can make it's way into the help text?

+1

Although I think Spondoolies has both the price and quality advantage at the moment. I just upgraded from 2 S3s to an SP20.

I'm seeing the following warnings in the Events page:


There's nothing alarming that I can spot in the Dashboard. All the temps are between 85 and 115C.

Should I be concerned about these warnings?

According to the Vertcoin blog, they're estimating the hard fork will happen on December 16th. They've tied it to a specific block.

In a post on the Vertcoin blog they indicated this fork was a strike against ASICs and a move against multi-pools.

Back in September I asked how this would affect Wafflepool, but I don't think there was an answer. I assume that Vertcoin would be dropped entirely, unless there's enough other interesting coins using the Lyra2 to warrant creating a new pool. I googled that and found no other coins using Lyra2, but honestly I don't know if any exist or are planned.

Again I'll ask what happens to the Waffelpool Script-N pool without Vertcoin? Is it worth keeping around for just murraycoin and spaincoin, or will it just be shut down?

Ordered an SP20 on Sunday and received it in California on Wednesday. I'm running with stock settings in an air-conditioned server closet on a pair of CX750M PSUs and getting about 1.675 GHs. The PSU wires and connectors are cool as a cucumber, although they were slightly warm to the touch when running in my office with a higher ambient temperature.

Easy to use, worked out of the box, simple and clean administration, no fuss no muss. This is a great upgrade over the pair of S3s that the SP20 is replacing. Overall I'm very happy.

One question though. I'm running with the same 2.5.26 firmware that shipped with the unit. Now the admin web app is telling me that I can upgrade to 2.5.33.

I went to the Spondoolies technical blog and can find no information about this firmware version. Can someone tell me what has changed in this version? It would be nice if the update page itself contained a summary of the changes.

In general I shy away from updating firmware unless there's a reason to do so. Once I have a miner configured and productive, I don't want to mess with it, unless it's a new product or has actual problems.

Sold!

Maybe the OP should rename this thread to "Underclocking the SP20 for fun and profit". Then it would be more obvious for the tl;dr crowd

Sale pending; in escrow now...