The Acorn FPGA GPU Accelerator | The Ultimate Guide to Enhanced GPU Mining

Hey guys! A few months ago Squirrels Research Labs came up with an FPGA that fits into the M.2 slot in your motherboard to optimize your GPUs vs having to swap out your GPU for a full blown FPGA to mine like I have been building. This is a pretty ingenious idea.

I like this concept as there are thousands of GPU miners out there that are running their machines faithfully and are familiar with what makes their GPU optimized for different algorithms and there is no programming needed. All of the tools are available for gamers for free giving miners a huge resource to under/overclock their GPU for maximum profit or coins.

The need for a hybrid FPGA/GPU

As you may know I am developing a DIY FPGA platform so the average miner can install their own customized bitstream. For those of you biting at the bit to get some exciting FPGA action, I wanted to talk to you about the Acorn.

Many FPGA developers like myself have underestimated the sure amount of work to program these bitstreams and boy do they take a lot of time! To fully optimize the code you need to write everything by hand at a near hardware level which can be very difficult. You will need to do this for every algorithm that you make, but luckily once the algorithm is made you can swap between different boards easier, but one downside to this incredibly powerful tool is the hardware cost. I have literally spent thousands to buy the boards and software needed but what if you have already spent thousands on GPU mining rigs? What if you have multiple rigs, can you use your GPU’s with the FPGA boards? No, you would replace the GPUS for the FPGAs or build a whole new rig for the FPGAs. We are talking about a bit of money, but what if you could have an FPGA that makes your GPUs hash faster? That is what Acorn does.

So what is the Acorn?

Acorn is a tiny FPGA that fits into your M.2 slot on your motherboard to help your GPU hash about 30MH/s faster for memory intensive algorithms like Ethash and CryptoNight V1, while it has 60MH/s for Ravencoin, Monacoin and other LyraREv2 and X16r coins according to their website.

How does it work?

FPGAs are great at pipeline parallelization where computing tasks can be split into function and replicated. They don’t perform well in serial processes or even serial parallel very well, so the goal here is to split the tasks into memory intensive and processor intensive tasks and offload the CPU/GPU processing to the FPGA. GPUs are pretty good at tasks that change constantly, while the FPGAs can do this but require expensive memory to be installed on the FPGA.

What hardware is needed?

You will need a motherboard that has M.2. M.2? What is that? It is a slot that accepts PCI Express Mini cards, usually used for SSDs. Check out Erik’s article for more M.2!

Example of a M.2, picture by Richard Lewis

The slot that this 960 Evo sticks into is the M.2

Next, you will need the proper configuration, you can technically mine on the FPGA directly, but due to its size of logic gates (100k-200k vs 1.2M-2.5M on a PCI FPGA) it would be quite slow compared to the hybrid combination they suggest using GPU and the Acorn FGPA. So you will need at least one GPU and one Acorn.

The geeky answer:

The FPGA fits into a motherboard that has a M.2 x4 slot Gen 3, which is a PCI Express Mini Card. First off the interface offers PCI Express 3.0 (up to four lanes), Serial ATA 3.0, and USB 3.0. When using Solid State Devices (SSD), it will work in NVM Express (NVMe) mode which is awesome because it is designed to fully max out the PCIe bus (with hardware parallelism of course!) in “M key” 2280 (actually 2390) configuration. This means that the board is 23mm x 90mm long, so make sure your board has 10mm extra to handle the card. For more information on M.2 terminology check here. From here you will need to have the proper config to acorn ratio. Check out the table below for more information on how to optimize for your configuration.

Chart to explain what Acorn FPGA to buy

What if my M.2 is under my PCI card and won’t fit with the acorn’s heatsink or I want more than one acorn but only have one M.2 slot? You will need to use a PCI riser card, they recommend the Asus Hyper M.2 x16 Card Expansion with NVMe, but any compatible PCIe M.2 M Key adapter should work. Just make sure you match your PCI motherboard bus to your expansion card bus speed, in this case PCI 3.0 x16.

What software is needed?

Just their custom miner and everything else is plug n play! Great job squirrels!

The geeky answer:

This board is preconfigured to run a few algorithms so on the board you’ll be fine if you plan on using ETHASH, CRYPTONIGHT V1, LYRA2REV2, X16R. All you need is their custom miner that is fee free. Yea! You can find the SQRL miner here. The miner can mine multiple algorithms which I imagine the acorn will mine shortly, they are ETHASH, CRYPTONIGHT V1, CRYPTONIGHT, CRYPTONIGHT-LITE, CRYPTONIGHT-HEAVY, LYRA2REV2, X16R, TIMETRAVEL10, X16S, PHI2.

What about OhGodACompany’s software upgrade, how do I install that? OhGodACompany’s ETHlargementPill is built in. Woot!

Price and Availability

Chart to determine what the acorn hashrate and power requirements are
Power requirements and hashing power for the CLE-101 Acorn FPGA
Power requirements and hashing power for the CLE-215 Acorn FPGA
Power requirements and hashing power for the CLE-215 Acorn FPGA
Power requirements and hashing power for the CLE-215+ Acorn FPGA
Power requirements and hashing power for the CLE-215+ Acorn FPGA
Power requirements and hashing power for the Dual CLE-215= Acorn FPGA
Power requirements and hashing power for the Dual CLE-215+ Acorn FPGA

Acorn just went live for Pre-order yesterday! Unlike huge PCI based FPGAs that cost thousands and have a lot more logic gates, the acorn is moderately priced at S199.99-$329.99. So what do you get for these price points? Look at the tables above for a detailed comparison.

Thoughts and Conclusion

I have to give my hats off to these guys, they really made a complicated system easy to use and pretty straightforward for a price point most can handle. This is a big step forward in the crypto world and I particularly love that they are utilizing existing GPU hardware, pretty amazing. I also like they have all their SDK and API’s available to help expand the community.

Overall this is a pretty good price, as with a lot of new mining hardware there is a bit of healthy skepticism, but I think for the price point and the way they have been developing it, they seem pretty legit. I have reached out to David at squirrels research labs to ask for some review copies of their product, so stay tuned to see if they are able to let us review it on our mining rigs!

UPDATE: We have a live webinar witg David from Squirl labs set for 8/3/18 at 3pm EST USA. Click here for more info -> Live Q&A with David from Squirrel Labs!

As always learn to live free each and everyday!

For the past 20 years I have been advocating and teaching about Renewable Energy and Alternative fuels. I worked in IT for 9 years and ran a few IT businesses during that time. I have worked wind turbines and in fuel cell technology and I currently teach college courses full time in Renewable’s and Alternative fuels. I am passionate about technology, building things, family and having fun outdoors. I love sharing and helping to make the world a better place in my own way.

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Sounds really interesting! Will keep an eye on this project! Greetings from Switzerland.


Hello Abe,

my question,

I have a 2 Rigs with 7cards (RX580 8Giga) and I dont know if i can “install” the hardware etc.

I have a M2 Slot (is empty at moment) …..

So, what i need exactly? one CLE-215+….and one 960 Evo stick??

sorry for my stupid question, but my english is not so good, that i can understand all what u write about this FPGA GPU Accelerator.

Also I dont know is works with 7 cards Mainboard and if I need to programming something after I have the CLE-215+?

Thx so much for your help and very good work here!!




I have 6x1080ti RIG and i am thinking about 215, i have 2 M2 slots. Do you suggest to get duo 215 or just single?


Hi Abe, Thanks for spending the time to write this great article and researching the Acorn, I watched the webinar and this is going to be really good for the small miner. With the current crypto prices and high energy costs (UK), we are hardly breaking even. Therefore this could really make a big difference. I’m trying to get my head around the maximum Acorns I could support for my setup below? how many Acorns could I use for the setup below? would I have more performance if I removed one of the GPUs and added an extra acorn? Also… Read more »

Eslam Attya
Eslam Attya

Hello Abe,

my question,

I have a 1 Rigs with 5cards (RX470 4Giga).

I not have a M2 Slot , so i’ll using Asus Hyper M.2 x16 Card.

How many Acorn CLE-101 do I need?

I can use Acorn CLE-101 with windows operating system?