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Topic: GekkoScience BM1384 Project Development Discussion - page 31. (Read 146713 times)

legendary
Activity: 3416
Merit: 1865
Curmudgeonly hardware guy
Wow, that datasheet is a heck of a lot better than they've put out before! I really like that the protocol is detailed.

Regarding the pinout and such, they did implement a lot of the stuff that's been mentioned in this thread. Given this chip's been in development for months I'd say they beat us to the punch, but that doesn't mean I don't like it. Also if I'm reading right, I think the _A pins are the signal pins with integrated level shifters? And an integrated 0.9V LDO for the PLL?

Dude. I really want to play with some of these chips. You know how much easier the designer's job gets with integrated level shifters? Holy cats.
hero member
Activity: 767
Merit: 500
I'm not sure you'll get the full 32.5 GH/s per chip with the undervolt to .6 volts per chip, but should be fairly close with a small undervolt like that at worst.
Depends on how much "overclock" headroom the chips turn out to have.

Trick is to keep the cost under 1/4 of whatever a S7 ends up selling for, otherwise it would make more sense to just get more S7s.

Are thel BM1385 chip specs posted yet anywhere?


Do you mean the datasheet that is available on Bitmain website since the announcement of the chip?

https://bitmaintech.com/files/download/BM1385_Datasheet_v2.0.pdf



looking at the footprint, yet another different layout Again! at least this one looks a little more logical! no more odd blocks and tracks to throw the VCC in.. buuut still have to physically see it it might still bee some odd block for the power..
legendary
Activity: 1498
Merit: 1030
I didn't see it either when I looked for it the day after the original announcement.

 The limited number of voltages listed has some interesting implications - seems like we are definitely hitting the hard limits on 28nm (not a shock if it's full custom), though I'm a bit supprised that the max voltage listed is so low.

 I'm even MORE supprised that the "default" is now a mid-voltage point, as opposed to Bitmain's normal "highest voltage is the default".
 THAT makes me wonder if the S7 is going to turn out to be a 17 chip per string device, not an 18 as some of us have speculated - but upon reflection, no way they'd have published that "230 watts at the wall per TH" claim if so.
legendary
Activity: 872
Merit: 1010
Coins, Games & Miners
Yeah, that datasheet wasn't posted when I looked for it a few hours after the announcement. I hadn't checked back, thanks for the link.

If the datasheet is less complete than previous, it must be pretty sorry because the previous datasheets were severely lacking in data. I'll tear into it here in a few hours when I'm not placing parts on Compacs.

They put the protocol on the sheet: Nice.

The package outline seems QFP? Nice.

OMG, hope they did read this thread.
legendary
Activity: 3416
Merit: 1865
Curmudgeonly hardware guy
Yeah, that datasheet wasn't posted when I looked for it a few hours after the announcement. I hadn't checked back, thanks for the link.

If the datasheet is less complete than previous, it must be pretty sorry because the previous datasheets were severely lacking in data. I'll tear into it here in a few hours when I'm not placing parts on Compacs.
hero member
Activity: 686
Merit: 500
FUN > ROI
Less specs maybe because they don't want to sell the chips, at least for now.
Maybe -  or they just forgot to include those drawings into the PDF.. plenty of other technical detail in there for those wanting to get a bit of a head start.

We'll see, whenever...
[...] Bitmain expects that the next-gen chip will be available for consumer purchase in the near future.
...near future may be Smiley
hero member
Activity: 840
Merit: 1000
Do you mean the datasheet that is available on Bitmain website since the announcement of the chip?
Technically that was posted a bit later (had to adjust wiki when it popped up).  It's also somewhat incomplete compared to the previous chips' datasheets.  Unless I keep scrolling past it, there's no package outline - and even fewer sample points on hash rate/power.

Less specs maybe because they don't want to sell the chips, at least for now.
hero member
Activity: 686
Merit: 500
FUN > ROI
Do you mean the datasheet that is available on Bitmain website since the announcement of the chip?
Technically that was posted a bit later (had to adjust wiki when it popped up).  It's also somewhat incomplete compared to the previous chips' datasheets.  Unless I keep scrolling past it, there's no package outline - and even fewer sample points on hash rate/power.
hero member
Activity: 840
Merit: 1000
I'm not sure you'll get the full 32.5 GH/s per chip with the undervolt to .6 volts per chip, but should be fairly close with a small undervolt like that at worst.
Depends on how much "overclock" headroom the chips turn out to have.

Trick is to keep the cost under 1/4 of whatever a S7 ends up selling for, otherwise it would make more sense to just get more S7s.

Are thel BM1385 chip specs posted yet anywhere?


Do you mean the datasheet that is available on Bitmain website since the announcement of the chip?

https://bitmaintech.com/files/download/BM1385_Datasheet_v2.0.pdf

legendary
Activity: 3416
Merit: 1865
Curmudgeonly hardware guy
All our boards should have full-range voltage control. There'll be no 0.6V upper limit. If the S7 doesn't have inherent undervolting ability, our board would actually be better so even priced the same it'd still be the smarter purchase because the viable life is significantly extended without hacking required.

If we can't build the boards priced low enough to be worth buying, we won't build 'em. If the only way to do it is to either outsource manufacturing to a slave-labor or near-slave-labor country, or crap on the design in a way that kills flexibility or reliability, we won't build 'em.

I have seen no chip specs released yet except the sparse data that's been posted in BM1385's announcement.
legendary
Activity: 1498
Merit: 1030
I'm not sure you'll get the full 32.5 GH/s per chip with the undervolt to .6 volts per chip, but should be fairly close with a small undervolt like that at worst.
Depends on how much "overclock" headroom the chips turn out to have.

Trick is to keep the cost under 1/4 of whatever a S7 ends up selling for, otherwise it would make more sense to just get more S7s.

Are thel BM1385 chip specs posted yet anywhere?
legendary
Activity: 3416
Merit: 1865
Curmudgeonly hardware guy
They don't have to come from Bitmain either, if anyone else would be willing to let us play with their silicon. Avalon, Innosilicon and LK (unless they're using Innosilicon's chip) could contribute. Bitfury and 21e6 are technically able but very likely unwilling due to their selfish and/or nonsensical business models.
sr. member
Activity: 462
Merit: 250
BTW, using the projected design one could get 8 20 chip boards into a C1 chassis versus 4 for the S1/S3/S5 making it a 5.2 TH/s liquid cooled machine drawing ~1125W.

And all we (the community) needs are the chips.
sr. member
Activity: 462
Merit: 250
I would also like to see a more efficient (via more chips per string or via controlable voltage regulation) BM1385-based varient.
As far as as I know, the 18 chip board will be a 20 chip board whose mounting is hole compatible with 1/2 of a S1/S3/S5/C1 heatsink/waterblock.
Assuming stock clock and Vcore with an operating efficiency of .216 W/GH/s and 80 chips total. 80 x 32.5 GH/s = 2600 GH/s (2.6 TH/s) drawing ~561W.
IF GS et. al. works a little magic and permits Vcore adjustment (which likely they will) this board via devolting/declocking will remain profitable to operate well into 2016.


Do the S1/S3/S5 all use the same frame mount points for their hash boards?

Plus/minus a couple of holes and in a word, YES.
and because the C1 uses S3 hash boards that unit can be included as well.

Now if Bitmain will sell chips, which currently they refuse to do, this endeavor could proceed forward.
legendary
Activity: 1498
Merit: 1030
I would also like to see a more efficient (via more chips per string or via controlable voltage regulation) BM1385-based varient.

 Do the S1/S3/S5 all use the same frame mount points for their hash boards?
legendary
Activity: 1008
Merit: 1001
I sure hope s1 repurposing with the latest chips is still on the agenda....


Ditto, been hanging on to my old S1 since that potential was first announced.  Hope to see it come to fruition soon, maybe in time for this coming winter.

I got a butt load of S1's, S3's, and C1's as well.
To the best of my knowledge it's Bitmain not selling chips is the holdup.

Would be nice to see an S1 running on BM1385 chips  Grin Wink (just kidding)
I would be pleased to get boards with the BM1385 chip with a better efficiency than the S7  Cool Roll Eyes Shocked Grin
sr. member
Activity: 462
Merit: 250
I sure hope s1 repurposing with the latest chips is still on the agenda....


Ditto, been hanging on to my old S1 since that potential was first announced.  Hope to see it come to fruition soon, maybe in time for this coming winter.

I got a butt load of S1's, S3's, and C1's as well.
To the best of my knowledge it's Bitmain not selling chips is the holdup.
legendary
Activity: 1274
Merit: 1000
I sure hope s1 repurposing with the latest chips is still on the agenda....


Ditto, been hanging on to my old S1 since that potential was first announced.  Hope to see it come to fruition soon, maybe in time for this coming winter.
member
Activity: 125
Merit: 12
I sure hope s1 repurposing with the latest chips is still on the agenda....
legendary
Activity: 1302
Merit: 1068
We can be hopeful about that announcement portion:

Quote
Bitmain expects that the next-gen chip will be available for consumer purchase in the near future.
I'm not sure if "consumer purchase" is exactly what "we"/sidehack need but at least it seem to be on the table.
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