US: 1-800-809-MINE (6463) | International: +1-913-815-8801

The Monarch
Butterfly Labs 28nm Technology Bitcoin Mining Card


The fastest and most power-efficient
Bitcoin miner yet

Datacenter ready PCI cards

Cloud hosted mining makes it flexible and easy

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We are pioneers of the industry - having manufactured the first commercial Bitcoin mining hardware.

Butterfly Labs has shipped more ASIC products than all competitors combined

BFL Truck

The Monarch 28 nm Bitcoin mining card is our 4th generation bitcoin processor - our 2nd generation ASIC chip.

BFL Facility

Our facility in Kansas has the largest production capacity of all Bitcoin hardware manufacturers.

Our engineering and management team has deep experience in technology and the Bitcoin space.

Why Butterfly Labs?

bfl logo

$ 3.66 /GH

0.6w per GH

Professional and expandable card design

4th Generation miners since 2011

The Competition

at least $ 17.50 /GH

2.5w per GH

Bulky Case design

1st generation late 2013


Power Consumption

Form Factor


Tough Questions about the Monarch Card

QWill the power & performance really be that good?


BFL began making bitcoin mining hardware in 2011 with the announcement of the now famous FPGA 'Single'.  The delivered speed was within target range, but the power consumption was higher than the design simulation indicated.  The product was a smashing success.

With that experience under our belt, we baselined our models and started in on our next chip for what became the iconic FPGA 'Mini Rig'.  That 2nd generation chip met both its speed and power consumption specs with perfect accuracy. 

How did we get perfect accuracy?   We were able to use real life data in our simulation models from the prior generation chip. 

So fast forward to our first generation ASIC chip which was an original design.  We delivered exactly the speed promised, but the power consumption was higher than predicted.  That caused a controversial release delay while we adjusted the PCB to accommodate additional power.  That 65nm ASIC chip is now powering the majority of the bitcoin network.  It's an excellent chip and its real world data has given us the bench test results needed for baselining our simulation models when we began optimizations for the 28nm chip. We are confident that our Monarch will be able to produce 1.7 GH per Joule, an eight-fold increase over our 65nm ASIC products.

In sum, the value of a 2nd generation chip can't be overstated.  It allows us to optimize with great vision and it takes the guesswork out of calculating power and speed in the final silicon design.

The bottom line is that BFL is the only 28nm chip manufacturer on its 2nd generation ASIC.  If you want the benefits of a mature & proven design, there's only one option.


QCan I transfer my existing order into a 28nm Monarch card ?



You can apply the purchase price of any undelivered end-user product towards a 28nm miner by paying a 10% transfer fee. (This transfer cannot be applied to bulk chip orders.) That will close out your old order and credit your account towards the purchase of a 28nm Monarch pre-order.  However, we do recommend you keep your remaining 65nm orders and take delivery because you'll get your mining gear much sooner.  28nm products won't begin shipping til year end and the network hash rate is expected to be much higher at that time.  It's also worth pointing out that FPGA era products were still very valuable well into ASIC generation rollout, and the relative power difference between 65nm and 28nm is much much less.

To see how much transfer value you have, log into your account dashboard and follow the transfer instructions to jump queues.

QCan you host these for me?



Cloud hosted mining makes it easy.  Although Monarch cards have a USB plug, so you can run them outside as a computer peripheral if you want, they've been design optimized for PCIe use in rack mount data center servers, or any standard ATX motherboard.  An example of four BPU's in a 4U rackmount

Butterfly Labs has arranged to provide cloud hosting of your Monarch cards with either Six or Twelve month hosting terms available at checkout.  Your cloud hosted miner will be set up and made accessible to you online.  All maintenance, hosting, power & software setup will be provided.  All you need to do is configure your bitcoin wallet address and hit 'go'.

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Pre-Order Terms