Antminer Z9 mini ASIC technology

Little is publicly known about the nature of the ASICs in a Z9. I’m personally quite curious how it deals with the memory bottleneck. The intent of a memory hard PoW is that it would use more memory than can fit on a single chip, so that an ASIC would have to use off-chip memory and performance would be constrained by the bandwidth and power consumption of all those IO pins.

Perhaps we can analyze whether the given Z9 performance is consistent with such an approach. Let’s see how much data needs to be read and written in one second.

10k solutions corresponds to solving 10k/1.88 instances, each of which needs to read/write 145 MB for 9 rounds, so that’s roughly 7 TB (3.5 TB written and 3.5 TB read).
Can DDR4 or LPDDR4 DRAM do that while consuming under 300 Joules?

If not, then the Z9 would have to avoid off-chip communication.

So this question is important for determining whether a change in Equihash parameters, e.g. to (144,5) will reduce the efficiency of future ASIC miners.

Update: This article

suggests it’s possible with HBM memory. But it would require the ASIC to consume a small fraction of the power of the memory IO.

I also found this paper

which gives 70 J/TB for DDR3 and 40 J/TB for LPDDR2,
and only 3.7 J /TB for Micron HMC DRAM reads.


I think the assumed 7TB can be roughly reduced by a factor of 2.5, that’s an educated guess so to speak.
Given the memory power consumption values are correct it seems perfectly doable while consuming under 300J.
This implies that changing the Equihash instance to (144,5) would not reduce the efficiency of ASIC miners.

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Memory dual channel >>>>> Memory multi-channel

for example,32-channel ddr3(128MB),or more
Customized BIOS
MCT(Memory Controller)There’s a rumor that bitmain got a technical problem here, patents are in big companies like Intel. The chip they developed could not bear the pressure of eth on memory, so the F3 (ethash 1.5G) won’t be mass-produced soon.

I made the mistake of purchasing 8 x Z9 Minis and started mining beginning of September 2018 - obviously ZCash. I will not encourage ANYONE to do so, the ZCash difficulty level increases weekly, the cost of running the ASICs are MUCH higher than any projected “profit” - which, by the way, was “projected” as $20-$30k per year ! With almost nothing else to mine, it is just NOT WORTH IT !

I understand you have no hope to ROI, but do you still make enough to cover electricity costs? At what point would you simply lose more money by turning them on?

Well, it obviously depends on what you pay for electricity, as well as the amount of money you generate (the fluctuating value of the crypto coins you mine). Yesterday. the value of crypto dropped drastically and I LOST (without considering electricity cost) around R350.00 At the moment my electricty costs around R35 per day and today my portfolio went up with a whopping R 21.50 Theoretically it is already time to switch them off !

(Unless you’re a hobby miner then none of that really matters too much)
According to profitability calculators, the return vs cost normal settings, 0.1 kilowatt hour is still better than 3 to 1
it’s known that most of the hashrate belongs to large Farms so we can assume they obviously have overhead cost, wages, so the conversion is much more important to them then hodlrs

in practice this is fake news.

with 0.20$ per KW ROI is @ 10 months (with ZEC @ 110$)

the fact you were expecting 20-30k in a year with 8 minis (80Ksols-120Ksols) payed less than 7k is way too exagerated and you should lower your expectations (generally in life).

Not saying you wont make over 30k mining Zcash, but just don’t expect them short term.

What you will be mining in a year is going to be worh more than 100k in 20 years (personal opinion)


Profit base on today rate.
8 x Z9 mini still have USD30 around per day.
assume your KWh 0.15

ROI about 7 months only.
even with expected difficulty keep raising.
I believe you can cover your cost within 1 year.

not bad man…

To be honest, for USD110 per ZEC, If I were you, I prefer buy ZEC direct instead of mining…

The less your rewards are worth (fair market value), the less you own in taxes…
Loving these low low prices!
Now back to z9 mini asic technology : )

Stability good at 650mhz (maybe higher) memory consumption that level

, closer to 700 seems like extra cool temps are key for stable chain (fan idle low 3k rpm range, pcb’s 40’s, chips mid-hi 50’s)
Ill turn it up when it cools down more to compare

No idea where you life and why you expected "projected 20-30k per year revenue from these 8 mini units.
As i own my own some it’s still more than profitable at the moment and i have no clue why someone would switch them off other than selling these units eventually.

If you made your calculations based on the profit calculator at the time you purchased/paid them than it’s more than obvious that this projected profit never can hold for 12 months. Have in mind you are one of 1000’s that purchased a given batch and never the only one having the privilege buying an asic…

I see people can OC it to 750 without problem and hashrate over 16KSOL on a Batch2 one.
** Attached photo NOT from me I get it from online only **

I had 1 batch 1 run for 2 months @ 750 then 1 hashboard start failing.

Then I lower to 713~ and it failed after 2 weeks.

Now I keep at 650, and for now hashing at 14k-15k

failed mean burned hardware failure??? I see bitmain ask for USD200+ for 1 board…

No they do about 5-ish ksol apiece at that speed, with only 2 would be 9-10 ksol range max

Not bad ? It is terrible ! After ALL this effort I am back to square one in a YEAR ? Not my idea of a good investment … BTW, yesterday I made $13 with FOUR minis. In an air-conditioned room with overclocked units !

This was NOT for 8 units - BUT FOR A SINGLE DEVICE ! Obviously from some of these clever people that (most likely) have a stake in the manufacturing. Call me gullible, but I still have faith in humankind and I respect honesty and integrity. My calculations was based (like any normal person would do) on (1) how long for a ROI ? (2) When will I actually start MAKING money ? (3) How much would I be able to make ? Sadly, I doubt whether I will even reach break even.
Sell ? Who would buy something that does not even let you break even ?
My post was intended to warn potential buyers of the Z9 Mini - if I had to make that decision today, the answer would be a massive “NO” !

I bought myself some units of the Z9 mini from batch 1 and 2 and it was obvious that batch 2+ will have a hard time to roi so i adviced as well not to buy from there on as it gets high risk if someone will reach his ROI forward on. But than again, when i made my calculations of a possible ROI i don’t use the current profitable income for the next months. And that’s mostly where you made the mistake.

However, your final point is of course valid, that buying from now on doesn’t make sense in case your electricity cost is 0.05+ kw/h… Just true!