Topic: rumors of 3.5Th antminer S7 "lite" (Read 8777 times)

Very interesting. Before i saw this picture, i did not want to but this batch, but now... I don't think so, perphaps it could be a good idea...

Thanks Rich!!

So following the publication of the picture of the Batch 8 Hash Board on the Bitnain Product page this is my current thinking.



As we knew they have removed 3 triples, 9 ASIC's, from the chain. However rather than that being it, which never completely added up because the resultant increase in the Core Voltage from 0.6V to 0.8V took the chips way off the data Sheet and would have ruined the efficiency. So they have removed the chips from the bottom of the chain and my best guess is that the have added a Buck converter to the board, in the vacated space.

We can see the large inductor & capacitors and I am assuming that the Buck Converter chip is on the other side, which they are choosing to keep from us at the moment.   So assuming that is correct I am further assuming that the 45 chips are still arranged as a 15 Chip triple node string. The buck converter presumably reduces the 12V to around 10V, giving us a hybrid design. In fact an integrated version of what we have been playing with on the S5 with a 12V PSU and an external Buck Converter.

The big unknown here is have they made this voltage software adjustable to give say 0.55V to 0.75V / Chip, or is it a fixed voltage? If they have done this perhaps it was done as a reaction to the Avalon6 which has an automatic frequency / undervolt algorithm?

Either way although there will be a small loss in efficiency with the Buck Converter but a gain in flexibility and overall be it software adjustable or good old pencil mod I think it represents an improvement over the straight string design.

It is also possible that I have completely misunderstood what the components are and the change that they have made is for something completely different.......


Rich

The problem with this is now if you did that it will void your bitmain warranty... which kinda sucks.  You basically have to have permission from them to do anything at this point.

I agree it would be interesting to see some of the chip counts.  They keep jumping up and down it's hard to keep track.  I think the S7 will be remembered as the miner that never really kept one speed.  It is very odd for them to keep changing it each batch it seems at this point.  I do admit I like they went up and not down on last batch put up on hashing speed.

It would sure be interesting to know if the 135-chip miner is actually a de-populated 162-chip miner with "dummy jumpers" in place of the missing chips. I hope that somebody that gets a Batch #6 or Batch #8 opens it up enough to count.

700M !!!!!!!!!!!!

Wow got a guess right.   Batch 8 is a 135 Chip Variant.



Rich

I have this feeling that we will never get to the bottom of the S7 variants. I have seen mention of at least 3 board revisions, but because it's a closed unit with the Boards covered in mini heatsinks we may not get any good pictures to see if the changes are cosmetic or just a BM1385 selection?

Rich

i think they are rising the default frequency because is winter and because they are acceleratin the roi for this products; but maybe they changed the headsinks design for this batch...

Maybe they buffed out some of the issues with the earlier batches and did a 4 th unit to just be on the safe side of things.  After some testing they said ok everything is good lets drop a 5 th unit and start pushing out more of these chips.  It is interesting to note that shipping times for batch 6 & 7 are exactly the same, so that would lead me to believe they had both these machines designed at the same time.

I think it makes more sense the 5th vs the almost 4th on the 3 blade design.  I just think 10 PCIe for 4TH is to much, and I know some are going to say you can use less... and i'm sure some do but I have been following bitmain's warranty on last few miners.

I cannot for the life of me figure out the up vs down.   But I think they will end up closer to  5th on future batches maybe they got quality up or something, or they had better yields.  There has to be something behind it, and I'm guessing it's tied to money.

Maybe they are dealing with different fabricant that can do one but not the other? Its nagging me, as to why they are doing this, as i can't come up with a reason. Sure they have lots of BM1385's but that doesn't really justify doing random things with them?

Yes I guess we have several games... Guessing what they might do, guessing what it is while we wait for someone to get one, and Wishing for what we actually want.  

On the Wishing front yes I still think that a 2 Board S7 would be a great product. I am actually now torn between wishing it would be based on 54 or 45 chips / board? 45 chip I feel would be a very solid product with a lot of scope for over & under clocking and volting. Whereas 54 chips / board would push up the hash rate and I think respond well to overvolting which is much easier to do with a Server PSU than undervolting. Unfortunately I don't expect to see either...

Am still intrigued to find out why they have found it necessary to have so many variants? I can only assume that they are getting a very broad spread of BM1385 chips and this is there way of coping with this? As has been said already it's going to be a nightmare in the 2nd hand market to know what you are buying.

Rich

I would really like to see a two board S7 with a high chip permutation, with bigger heatsink, should make the thing very quiet during winter and make it cheaper to buy it single unit by single unit.

Back to wishing for a 3.5TH~ "lite" for Christmas.

Tough game this guessing.  Then again who would have guessed that we would have 4 different Default Frequencies / TH/s and 2 different chip count S7 in such a short period of time?

Still they are running out of permutations, unless we start seeing different Default Frequency 135 Chip versions. 


Rich

I suppose it give them more operational leeway, i'm guessing they realized that people trust them enough that they can get away with doing this, as it give them another edge. Interesting of them to make a step up in chips instead of down. Look like RichBC's guess did not come to be.

Sound a bit risky to buy in now, as with the difficulty increase, i'm not sure this unit will be worth 5BTC in 3~4 difficulty rounds.

Interesting they have a new batch.  It's almost like pre-ording you order so far ahead.  1.5 Month lead time to get product is a change in bitmain.  It is intersting as i would guess with 1.5 month lead time they could order all parts, etc from customers money not even need to use their own like when batches were made close to shipping date.

I really hope they push timeframe to less day's ahead when they look at more batches.

It seems that my forecast was wrong.    Batch 7 is another variation with 162 Chips, 5.06TH, 1270W, Default Frequency 625MHz, 0.25J/GH and Supply Voltage 12.0V+5%, should not be less than 12.0V

https://www.bitmaintech.com/productDetail.htm?pid=0002015111710183627718X85SYG0616

I can only guess that they are selecting BM1385 for these?


Rich

My money still on all future batches being of the 135 Chip, 4.05TH variety. Still intrigued to see what the actual consumption & J/GH these actually achieve? However we have a while to wait for first tests on a Batch 6, and there must be a risk that deliveries get slowed by Xmas?

Rich

They have did batches pretty far out really for them.  It's almost to point its kinda a pre-order I think you get a month or so ahead.  I mean the current batch could ship "between Dec. 7 ~ Dec. 17 (if shipped out 5 days later than it, it won't be considered as delay )." So Dec 23 ship out around a month and 6 day's and they are not late.

So It would not surprise me if we see another one of the newer S7's again just wait till it's closer to that batch being shipped or possibly  shipped.   I do not expect them to change it again or make a two blade, I think they are going to remain firm on current design at this point.

The new s7 is marked as sold out on bitmain so I wonder what the next batch has in store for us.  Are they going to produce another batch of the same, something different or drop a new chip and new unit.  I'd guess they just produce another batch but the drop in btc price has hurt their value since they are using a hard btc price instead of dollar.  Soo I wonder will they release something to the public?  The units they haven't even shipped yet so it will be some time till then