Most of my Avalon 841`s have a "15" under the PG column to the far right (hovering shows that as "Power Good").  One has a "3" and is underperforming.

Should I just swap the power supply?

Update:  I have spare PSUs, so went ahead and swapped it out.  Problem appears to be solved.  This is also the unit that was running about 4C higher in temp prior to the PG number changing.

Of course, will continue to monitor it.

Around 9am CST6CDT the vast majority of my antminer farm went offline.  At the moment I have about 150 S9s and a few L3s offline.

The miners physically look fine, with flashing green lights, no red lights (mostly), network activity, etc.  However the majority can not be pinged, and a few that can be are not starting up.

Current network topology:   PFSense firewall -> right side Netgear GS316 -> <fans out to 7> Netgear GS316 -> Antminer S9s
                                                          ->  left side Netgear 10-100 switch on right side -> Netgear 7 port gigabit switch on left side -> <fans out to 3> Netgear GS316 -> Antminer S9s & L3s
                                                                                                                                                                                                 -> Avalon 821s & 841s

My normal topology is to have the right side Netgear GS316 also support the left side, but I split the network using a redundant feed I had back to the PFSense firewall with morning in an attempt to isolate the problem.

Of my (76) 14TH S9s, (24) are active, the rest can not be pinged.  Likewise (9) of my (25) 13.5TH S9s are reachable - mostly on the right side.

The left side has (11) of (13) 13TH S9s working, (2) T9s, and (2) of ( "problem children" S9s.  All of the Avalons are fine, but of course, they are clustered behind a few PIs, so have a lower network port count.  (22) of my (26) L3s cannot be pinged.

So both the left side and right side is having problems, and they are independent of each other network wise back to PFSense firewall box.  Occasionally I'm seeing Antminers go blinking Red, but a quick power cycle clears that. 

I'm at wits end without a clue.  I'd be fine if I lost a switch.  But my problem children appear to be spread across several switch, and in fact, several physical networks.  The LAN side IP addressing is shared at the firewall, but I can't see how that would be a problem.

Although growing (with the latest batch of 34 mixed Antminers being added early this week), the network has been otherwise stable until this morning.

Somebody please!  Give me some ideas of what I am overlooking...

I decided to diversify my SHA256 farm and start mining some Scrypt, mostly because of coupons from Bitmain and then $505 list prices of L3s, combined with some empty shelf space in my data center.

Spent some time on Google, but unlike BTC pool information, not finding as many pool comparisons for LTC and its friends or specific fee structures.
Update:  Finally found https://litecoin.info/index.php/Mining_pool_comparison

Recommendations I found so far:

Solo hash - Pro:  no fees.  Cons:  LTC only unless I was to setup merged mining and manage multiple wallets.  Doable.

Litecoinpool - Pro:  Claims 0 fee compliments of merged mining.  Cons:  Cost money to run a pool, guessing they shave some off the merged mining and keep (currently trivial) transaction fees.  Concerns:  PPS pools TEND to have higher fees to cover themselves.  Reported in the Pool Comparison to charge 4%

Give-Me-Coins - Pro:  Smaller pool, merged mining, payout directly to each wallet.  PPLNS - so SHOULD have lower fees. Cons: (Minor) Need to maintain multiple wallets (already setup).  Concerns:  Pool Comparison claims 0% fee, but a pool must charge something to survive.

ProHashing - Pro:  Profit Switching, rumored to pay out substantially more than merged mining sites.  Ability to pay out in any coin, including BTC.  Cons:  Somebody is paying for all the transaction fees associated with mining multiple coins and converting them to payout coins.  Concerns:  Unknown fee structure.  Also, if they are so great, and pay a lot more, why isn't everyone mining there?

FYI: Out of principle, I refuse to mine on any Chinese owned or controlled pool.  Also trend towards smaller pools for the health of the network - so long as blocks are found on a weekly basis I consider them big enough (which is why Litecoinpool is just a backup for me now).

Basically, this boils down to trying to maximize my return, which usually means minimizing expenses.

Can anyone please help educate me on this branch of mining?

Hi all.

I run over a 100 S9s so am somewhat familiar with Bitmains front ends.

Just received my first (4) L3+s.  Hooked them up, powered them up (with APW3++s running on 220V), and waited.  And waited.  And waited some more (now 53 minutes), and all I get is the basic web screen.

S9s can take over 20 minutes during their first boot to scan the cards.  Figured the L3+ has 4 cards vs. the S9s 3, so it might take a half hour or so.  Now its been substantially longer than that.

Also find it odd that the kernel log is blank on all 4.  I can web into them, but otherwise zip.

Any suggestions?  Zero experience with these things.  Bought them because I had room in my data center, $400 coupons to burn, and a strong curiosity.

Correction:  Kernel log was just VERY slow to respond.  Looking for errors I found the following repeating in the logs:

Code:

Apr  3 23:38:37 (none) local0.err cgminer[8003]: Get [1]Temp Data Failed!
Apr  3 23:38:37 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][12]@ChainID:[0], Chip[C]
Apr  3 23:38:37 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][10]@ChainID:[1], Chip[C]
Apr  3 23:38:37 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][11]@ChainID:[2], Chip[C]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][10]@ChainID:[3], Chip[C]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][12]@ChainID:[0], Chip[C]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][10]@ChainID:[1], Chip[C]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][11]@ChainID:[2], Chip[C]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][10]@ChainID:[3], Chip[C]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][12]@ChainID:[0], Chip[C]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][10]@ChainID:[1], Chip[C]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][11]@ChainID:[2], Chip[C]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][1][10]@ChainID:[3], Chip[C]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Chain 0 chip 0 RemoteTemp 0x12
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Chain 1 chip 0 RemoteTemp 0x10
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Chain 2 chip 0 RemoteTemp 0x11
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Chain 3 chip 0 RemoteTemp 0x10
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[0], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[1], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[2], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[3], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[0], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[1], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[2], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[3], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[0], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[1], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[2], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[3], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[0], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[1], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[2], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Dump IIC Data:[41][98][1][0]@ChainID:[3], Chip[C9]
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: OK Chain 0 chip 0 local 0x12 remote 0x12 offset 0xfffffffa 
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Remote = 0 Chain 0 chip 1 local 0x0 remote 0x0 offset 0x14 
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: OK Chain 1 chip 0 local 0x12 remote 0x10 offset 0xfffffff6 
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Remote = 0 Chain 1 chip 1 local 0x0 remote 0x0 offset 0x14 
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: OK Chain 2 chip 0 local 0x10 remote 0x11 offset 0xfffffff9 
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Remote = 0 Chain 2 chip 1 local 0x0 remote 0x0 offset 0x14 
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: OK Chain 3 chip 0 local 0x10 remote 0x10 offset 0xfffffff9 
Apr  3 23:38:38 (none) local0.notice cgminer[8003]: Remote = 0 Chain 3 chip 1 local 0x0 remote 0x0 offset 0x14 
Apr  3 23:38:39 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][11][FA]@ChainID:[0], Chip[C]
Apr  3 23:38:39 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][11][F6]@ChainID:[1], Chip[C]
Apr  3 23:38:39 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][11][F9]@ChainID:[2], Chip[C]
Apr  3 23:38:39 (none) local0.notice cgminer[8003]: Dump IIC Data:[1][98][11][F9]@ChainID:[3], Chip[C]

Hi all.  Received my first batch of Avalons today.  I went to set up (3) strings:  String 1 was headed by a pi 1 with a single 821 on it.  String 2 was headed by another pi 1 with (5) 841s on it.  String 3 was headed by a Pi 3 with (5) 841s on it.  Once I found real data cables to use with the AUC3s (and found out just how many charging only cables I have!), the Pi 3 unit came up just fine.

The (2) Pi 1 units had AUC3's that were mostly blue but slow blinking green.  e.g.  They were more-or-less always in setup mode and resetting as soon as they came ready.  The Avalons behind those two Pis remained idle (yellow light).

I moved the AUC3s from those Pis over to the Pi 3 and confirmed the AUC3s were fine, the cables were fine, and that the miners were fine.  Currently running all (11) Avalons off that single Pi 3.

Curious if anyone knows what the problem was driving the AUC3s from the Pi 1s?  I thought perhaps insufficient power supplies to drive both the Pi 1 and the AUC3, so tried a 2.4 amp one - but had no change.

Any other ideas?

Hi all.  Running a farm of 100+ S9s.  Heat rejection for them is easy:  Stick the rear fan through your cold/hot aisle wall and the issue is solved (cold air in from the cold aisle, hot air out to the hot aisle).  Only downside is the power supply waste heat (7% of what is used, more or less) ends up in the cold aisle.

I have (11) Avalons coming on Monday and I've been trying to figure out an equally elegant cooling solution for them.  Alas their power connections are on the back of the machine, so if I played a similar game as I do with the S9s, I'd either need holes in the cold/hot aisle wall for power cables, or would need to put the power supplies in the hot aisle - which just doesn't sound like a good idea (and would involve some other minor redesign issues like moving power from the cold aisle to the hot aisle to avoid having the power cords going through the wall).

FWIW - I'll be using Bitmain APW3++ power supplies for the Avalons, mostly because I have an excessive quantity of them.  So many in fact that I've considered splitting them, with each power supply driving half of an 841.  e.g.   P - A - P - A - P...  That would at least prevent power cables from crossing the back of the exhaust area of the Avalons.

Any thoughts or suggestions?

Wondering if its possible to merge profiles?

For personal reasons, I've abandoned my old Sr. Member account (although I still have access) and started using this one.

I would like to have that account disabled and the Activity points merged with this account.

Is that possible?

In my opinion, more or less in order:

1)  Lowest fees - currently believe that is Kano.is at 0.9% with transaction sharing
1a)  Shares transaction fees - back in December, fees represented close to 40% of the per-block earnings at one point
1b)  Any pool that does NOT share transaction fees should be rejected from consideration (which, unfortunately, is most, if not all, Chinese based pools)

2)  Reasonable variance - you need to get paid often enough to be happy.  This is a tough one.  Comparing two pools that pass rule #1:

Slushpool - finds a dozen or so coins a day
Kano - finds a coin every few days
.
.
.
solo - only an option if you have several thousand miners or are good with getting a paycheck once a year or so or maybe never.

Variance is the close cousin to "luck".  The luckier a pool is, the more blocks it finds relative to its hashing speed, and the less variance it will have.  But its not a real thing!  "luck" could change any microsecond.
 "luck" is just mathematical statistics - over a long enough time period, all pools will average out to 100% luck.

You need to understand variance:  A big pool finds more blocks, but distributes the earnings out to more miners.  A small pool is just the reverse:  it finds fewer blocks, but pays those earnings to fewer people.  Over the long run, rule #1, well, rules.

3)  Wind-up/Wind-down time - most pools use some leveling algorithm.  Using the two above examples:

Slushpool - about 4 hours
Kano - about 12 days

4)  User Interface.  Slushpool wins hands down over Kano - but you pay over 2X in fees to have that privilege.  That doesn't matter much if you have a few miners.  If you have hundreds, the difference can be thousands of dollars a year.

Notes:

A) In the long run #2 & #3 really don't matter much.  Both pools show your hashing rate in minutes, payouts just lag on Kano compared to Slushpool, but would continue longer if you changed in the future
B) Bigger is not better.  Sure Antpool is #1 in size, in no small part to Bitmain using their own pool (no fees for them!).   Your profit will be determined mostly by rule #1 - lower fees mean more profit.
C) More, smaller, pools is healthier for the blockchain.  If you can live with the variance, support the pool with the longest average payout you are happy with.
D) For pools with long ramp up times that are relatively small, like Kano, you MIGHT suffer due to difficulty changes while you ramp up.  For smaller pools, make sure you understand what happens to your efforts (based on their scoring system) when a difficulty change occurs.

Personally, as I thought this over, I decided to switch my 1.3PH from Slushpool to Kano.

Upgraded my wallet to 16.0 recently and generated a new receiving address.  Noticed it starts with a 3 now?  I thought that indicated a multi-sig address???  

I run a farm of about 100 S9s currently.  I'm looking to do a purchase of a dozen or so more miners and am really torn on what to do.

Price/TH wise, especially with the coupons Bitmain has been providing, the S9 is still the winner.

However... the Avalon 841 has a lower power consumption/TH, worth about $100/year/miner to me in electrical savings/miner.  But they are more expensive, even with 2 years of running factored in.

However... adding more S9s now to add to the S9s I have been accumulating since June of 16 (yeah, I have a few Batch 1 S9s...)... well... they are feeling a bit old, architecturally.  Top that off with paying anywhere between $1296/S9 last April to $2725/S9 last December, and remembering them for around $1145 back in October, I have to believe that Bitmain will substantially drop their prices when they come out with their anticipated 14nm S11.  That would, of course, reduce the resale price for whatever I bought at todays relatively high $1915 (Even with $450 off coupons they are still more expensive than most in my farm).  Just looks what they did with T9s recently:  dropping from ~$2000 to $1400.

But... if I order S9s soon, I'll probably get about 20 more days of computing time.  At todays price & difficulty, thats about $6/day/miner after power cost.

And...  The next Canaan product, the 861, is close - but its just an 841 with an internal power supply - so no tech change.

Of course, if Bitcoin jumps to $25000 this December, anything bought now will appear to be a brilliant move.  But we are living in an $8500 bitcoin world today.

So.  Speculators:  Is anything coming in the next couple of months that will shatter the current price/performance/consumption curves?

What SHOULD I be worried about, given that I tend to buy about a dozen miners at a time as I fill my data center?  (e.g.  I re-invest as I go, so won't take a loan to buy 60-80 841's directly from China, although I keep thinking about that.)  FWIW:  The advantage of growing incrementally is that even mistakes get moderated out over time.  Of course, no quick riches either.

Your thoughts?

Oh, just to share on speculation:  Most of my Bitmain coupons expire in June.  Therefore I expect a major announcement and price drop on S9s shortly after expiration.

Hi all -

One of my S9s keeps dropping one card.  When I examine it, I see that one pin on the power connector is off-colored compared to everything else.  Often just resetting that connector will get the card up and running... for awhile.

Is there any way to clean that pin?  What would I use?

I have a couple of older fixed frequency S9s in my farm, including on 14TH one that is running at 13.6.

I'm just wondering what would happen I loaded one of the auto-freq firmwares?

My guess is that it would boot (controllers likely being compatible), but not find the cards?

Just thought I'd get some opinions before jumping...

Just a sanity check.  I wanted to make sure the Avalon uses the same 6-pin connectors and/or if there was some other surprise reason an APW3++ won't work.

I'm thinking of jumping over to Avalons from my current S9 direction and have well over 20 spare APW3++s.    I know the quality is as good as the Canaan power supply, but would hate to have them just gathering dust.

One of my 14TH/sec S9s has been running at around 12TH/sec due to one ASIC card working at about half speed.  The miner status panel showed 6 ASICs as missing (not X, just not there).  Ok, fine.  12TH/sec beats 0Th/sec for several months of warranty repair, so I just left it running.

One of the regulars here has repeatedly suggested downgrading to the 0417 firmware, which I did on this machine (and many others that were under-performing for no obvious reason).  Several of those under-performers came up from 13.3-13.5 back into the 13.8-14.1 range, which I considered a nice win!  Surprisingly, the unit with the missing ASICs came back with all of them showing and crunching along at its rated 14TH/sec!  Very Cool.  Thank you Fanatic26!

Alas, that was yesterday...  today I came in to see the missing ASIC unit running with only 2 hash cards, the other was visible, but not doing anything.  No change after a reboot.  For hells bells flashed it back to 1117 and it came fully up, but now thinks its a 13.5 TH/sec machine.

After running for an hour, the problem card is visibly under-performing:  http://puu.sh/zrgzx/f64f357763.png, but doing better than it used to do by a bit.

Going to just let it run so long as all 3 hash cards are doing something.

Just thought I'd share how fickle these units are.

ps.  Should add that the APW3++s are pretty fickle too. I think.  Seems like I can swap power supplies and sometimes problems go away for awhile.  Sometimes those swapped out power supplies run other S9s just fine.  Sometimes not.  I have (3) out of (103) that definitely have problems powering all three cards (and yes, I'm at 220V).  Fortunately, at todays $2320 miner price vs. $105 power supply prices, its, IMHO, just silly not to have a few spare power supplies if you have more than just a single miner.

Oh, for those of you in the northern hemisphere currently using outside air for cooling, I can definitely state that APW3++ power supplies do NOT like 0C air - or at least most of them don't.  I powered up (80) machines back in early December with temps between 0-2C and about 1/5th of them came up (the lights on the S9s would not even blink on the other 4/5th and swapping in a pre-warmed power supply would fix the problem.).  Fortunately I could open up my hot aisle and allow some air recirculation (now regulated with a thermostatically controlled exhaust fan that keeps my cold aisle around at least 10C).  As the temperature warmed, more and more of the power supplies started working.  It seems that 10C is a more realistic minimum for them.  Once running, they generate enough internal heat to stay happy.  I only state this since they are rated for a running minimum temp of 0C.

Hi - Had a T9 that is less than a month old crap out:  http://puu.sh/zqQiU/3f2bc88069.png

Went to the Bitmain site and appear to be in a catch 22:

1)  They want tracking information in order to create a repair ticket
2)  They want copies of the repair ticket in the package

I'm within the USA and planned on using USPS to deliver to their new California repair center.

Do I have to instead use UPS/Fed-Ex or some other carrier that allows me to go online and create a shipping/tracking number and then wait for some type of Bitmain approval?

Does anyone know where/how the firmware determines if an antminer is a 14TH/sec vs. a 13.5TH/sec box?

Is it one of the jumpers on the control card?  A setting in some configuration file?

It FEELS like the firmware finds that information somewhere, then autotunes the available cards to come as close as possible.  If it autotuned each card to its maximum, I would think we would see a spectrum of different speeds as "ideal" ones.

Hello all.

By way of introduction:  I run a ~100 node S9 farm that I brought up in early December.  Prior to that I ran a small cluster of around (8) S7s and S9s.  Got lucky and bought the bulk (80) of my machines during the brief 14THs sale.

The vast majority of the machines run just fine.  I've had a few APW3++ power supply issues, but swapping those out for new ones generally fixes those problems.

I have also had a few hash card problems:  things that new power supplies just don't fix, like this obvious one where a couple of chips are bad:  http://puu.sh/zmqcQ/be27eff6a1.png

Anyhow, yesterday one of my nodes had a card go offline.  Happens.  Normally a reboot and all is well.  Not this time.  When I rebooted, the system came up, but never started hashing.  Upon investigation I found the single board speed test seemed to be hanging... and I let one pass run over 12 hours to be sure.  OK, no biggie, standard process of disconnecting one board at a time and rebooting should identify whatever was wrong.  Nope.  Went through all 3 boards with no change!

Well, if it wasn't the boards, I figured it must be the controller... and fortunately I received some spares from Bitmain recently that I purchased just for this case.  For reference, the original controller card was version 1.20, and my replacements are 1.30... if that matters.

In any case, I swapped the controller and powered up.  All three cards are now running fine, but at 400Mhz.

Also for reference:

Hardware Version   16.8.1.3
Kernel Version   Linux 3.14.0-xilinx-gb190cb0-dirty #57 SMP PREEMPT Fri Dec 9 14:49:22 CST 2016
File System Version   Sun Jul 30 20:19:24 CST 2017

Interesting tidbits from the kernel log:

Chain[J6] has 63 asic
Chain[J7] has 63 asic
Chain[J8] has 63 asic
Chain[J6] has no freq in PIC, set default freq=400M
Chain[J6] has no core num in PIC
Chain[J7] has no freq in PIC, set default freq=400M
Chain[J7] has no core num in PIC
Chain[J8] has no freq in PIC, set default freq=400M
Chain[J8] has no core num in PIC

Which explains the 400M clock speed.

These leads me to my primary question:  How do I get the controller to run its speed test and auto-tune these back up to their proper setting?

I tried using http://172.16.4.155/cgi-bin/minerAdvanced.cgi to set the starting speed to 550M, hoping that would kick start the process.  The 2nd time I tried that, it appeared to work, but all cards are at the fixed frequency I specified.

Guessing I just need to flash one of the auto-freq binaries, but wanted to check and make sure before I potentially trash a $60 (plus ridiculous shipping) card.

Secondary question:  Can all the controllers support both fixed and auto-freq binaries?  If so, is there any reason to run fixed on any of my older miners that came with it?  Related, is it then just the mix of hash cards that determines if a miner is 13.5TH or 14TH?

Final question:  Anybody know of a trustworthy US based repair shop?  I don't mind sending in individual cards for repair, but no way I'm I going to send something like that miner with a few bad chips off to China for a few months of travel, losing all that hash the whole time.  I've previously used BitmainWarrenty (now MyRig), but am not 100% happy with them due to what seems like excessive repair time (several months).