Topic: Fair Price for a Spondoolies SP20 Jackson? - page 2. (Read 1762 times)

I'm doing the same thing.  I have been running underclocked for quite a while now.  It just made sense.  The 1.7 I don't care how cold you won't get this.  

But for everyone except "free" electricity it makes much more sense to underclock you make more BTC mining this way on SP20 Jackson.  I have never had issues with PCIe cable's.  But I have had nice PSU's on my miners and always been careful.

I wonder, what is the highlighted based on?
I run Sp20E very downclocked at ~1200Gh using ~640-650W at the wall from a single Corsair CX750M, which has 2 split PCIE cords providing 4 required connectors.
The cords or connectors never exceeded 45C and I have a lazer temperature probe.
I grant you that you have to first connect a more powerful PSU (like EVGA 1300) or two CX750, then change settings on the machine to downclock, check power usage, achieve stable hash and then optionally changeover to a single CX750, but it is doable. I run a machine like this for almost 9 mo with no problems whatsoever.

 Partly correct. The fan usage DOES come out of one or more of those PCI-E connectors (I think it's probably split between 2 of them, but haven't pulled my SP20 apart long enough to actually check it).


 DON'T count on 1.7 TH - you have to have a very cold room to even have a prayer of achieving that. 1.3-1.4 TH range is achieveable easily even in somewhat warm rooms though, and is quite a bit more efficient to achieve.

 Do NOT under any circumstances try to run 2 connectors from one cable, unless it is a VERY custom cable with something on the order of 12AWG wiring.

 SP20 does not have wireless. Standard twisted-pair Ethernet only.

 The official spec on the MOLEX connectors that the PCI-E power specification uses works out to 288 watts per connector (the pins are rated more, but have to derate for use in that particular connector style).
 Exceeding this tends to lead to issues like the KnC Neptune and some Titans had with MELTED connectors and resultant fire and damage-to-unit risk.

 Most power supplies use 18AWG on their PCI-E connections - this is plenty for a SINGLE connector at 225 watts (per the PCI-E spec), it gets a bit marginal at 288 watts.

First, ignore the +2 pins on both end, they're just extra grounds. Second, a double cable would work, the problem is it would probably heat, then melt, then maybe fry your stuff. I believe the safe level is 190w each for double. In this case you definitively will want to only plug one 6 pin per cable.

For the 6 pins @ 300watts, it depend on the connectors and the cables themselves. If its 16AWG it should be fine, you can easily find out by just touching it after its been running for few. If its hot, then its not good. Basically avoid 18AWG wires if you want to run 300watts in a connector.

Keep checking every other week because if it heat up, it may get worse and worse.

I've had bad cables work fine, warm, then hot, then melted after 1.5 years of 250watts each.

Last thing to keep in mind, if your PSU is pulling 1200watts at the wall, its not running 300watts per pci-e, since you need to deduct the watts wasted by the PSU conversion and also the fan's usage.

Alright guys, thanks. Yeah, I already have a bunch of PSU's lying around (from S3's)... I'm honestly thinking of selling them off in favor of SP20's... So much freakin' headache to have to run a crap ton of Antminers.

I do have a couple other questions and I hope you guys can help. Does the SP20 have built-in wireless? And if it does, is it less advanced than setting it up on an Ant? I don't mind either way because I'd have many less units, but just curious...

Secondly... I believe for 1.7 TH/s, you need to be supplying the unit with about 300 watts in each 6 pin slot... Suppose I were using a CX750m for two of those... Power-wise, the PSU can handle it I think... But the problem that concerns me is the 8 pin to 6+2 pin connectors. They kind of daisy chain two 6 pin connectors to that. Now, I know I would have to use each 8 pin independantly, because those two 6 pin connectors would want 600 watts, so that's out. And I guess the SP20 can adapt, but like I said, I want max hashrate...

If I take one 6 pin from each of the two 8 pin connectors, will that single 6 pin on each connector be able to give 300 watts to each slot? I hope what I'm saying makes sense...

I mean, I know for a fact that a single 8 pin to 2x 6+2 can power an Antminer S1, S3 etc with no overclock (though the wires get warm) Of course, each blade is only 130 watts, so it's a combined 360. Fine... What I'm asking is, can one of those 6 pin connectors be capable of delivering 300 watts on it's own through one of the connectors? My Rosewill Photon came with 8 pin to single 6+2 pin connector, as opposed to the double ones... Would that be required? We already know the 8 pin can supply the power... But is the single connector tough enough for that current? If both are daisy chained and all that current is running into one connector, then into the other, I would think maybe so... But I'm not sure.

Sorry for the novel... I just wanna make sure I'm equipt for getting these units only to have them sit and have to mess with things for too long. :/

350 to 375 seems fair.  Assuming it works and that your power is not crazy high.

Low 300's sound good. Anymore and you run the risk of it devaluating highly before you can make up the difference. On the other hand with the BTC price looking strong, it sound like a overall good deal if you can get it for 360$ shipped or less.

I see all kinds of prices on Ebay like well over $400, but given current state of things, that's kind of a lot...

I'm thinking that since price is looking good right now, and I have cheap electricity, ideally I didn't want to put more then $300 into one...

Any thoughts?

"Don't mine, it's a fool's game". Tbh, I just like the feeling of mining, and my electricity bills here aren't unbearable... Plus, if you get cheap hardware, in the longrun if you can front your electricity costs, the BTC you'll make, and their value in the longrun, could be much higher and your actual price/BTC may be lower in the end. Like I said, mining is just fun. When you're not having trouble...

What's the absolute max you'd pay for an SP20 nowadays?