Bitmain recently introduced the Antminer S5 with their next generation chip. The S5 has the familiar open blade design as the S1 with panels on the sides to direct airflow without being completely encapsulated as the S3. What makes the S5 shine are the new chips. The S5 consumes 560 watts in our tests and runs at 1.1 to 1.2 th/s.

Specifications Antminer S5:

• Hash Rate: 1155 GH/s ±5%
• Power Consumption: 560 to 590 W
• Power Efficiency: 0.51 J/GH
• Chips 60x Bitmain BM1384 Gen3
• Rated Voltage: 12V
• Dimensions: 298 mm x 137 mm x 155 mm
• Cooling: 1x 12038 fan
• Operating Conditions: 0 °C to 35 °C
• Network Connection: Ethernet

Review of Antminer S5

The shipping gods were benevolent this time and Bitmain sent them prepared in case they were not. S5 arrived very well packaged in a rigid bubble wrap casing. This new packaging protects the Antminer from damage it can take in transit. The first thing we noticed was how light the S5 is at just 6.5 lbs. This light weight is due to the use of plastic side panels directing the airflow on the outside as opposed to the full metal casing the S3 had. While they feel a bit flimsy the tight fit and well-placed screw’s keep them secure. The top and bottom are open with simple access to the top for the four PCIe power connections. The S5 is noisy due the single 120mm fan that drives the air over the blades not being the best. The Antminer S5 runs at 61 to 65 dB at 4 feet. While not an immediate divorce maker, they are not quiet enough to put in your living room.

Low Power Consumption, Solid Hashrate

For this review, we used a Dell 1200 watt server PSU with a custom breakout controller board being made in conjunction of HolyBitcoin and J4bberwock. (We will have a full review of server PSUs and breakout boards for them in the coming weeks.) We also tested with an EVGA 1300 watt Supernova. The S5 pulled 560 watts at 110v from both PSUs. For this test, we used BTCGuild and Antpool where the S5 consistently ran at 1.186 th/s. This aggressive chip brings Bitmain up to the top with the Spondoolies-Tech SP20 even slightly better. The move is a good one as falling BTC value has made each gh/s you can squeeze out of a chip at the lowest power usage a win.

The Antminer S5 uses DHCP to get on your network taking away some of the hassle of out of the box static IP addresses that may not be the same as your routers DNS setting. The control panel is the simple to use as always with the initial user name and password root / root. The password should be changed immediately. The pool config panel can quickly be populated as ever making the total setup to mining time short.

One criticism is the lack of the extra nonce feature many of Bitmain’s competitors have allowed for more coins and pool types to be used. The S5 work well on P2Pool from the start with none of the hiccups the S4 had. Bitmain’s Antpool can be used in P2Pool mode as all showing their promised commitment to keeping the global hash rate distributed. With Antpool being the second largest pool, it would be nice to see them follow through and move all of their power to P2Pool. As of now the choice is manual between “solo mining” and P2Pool on their pool.

The Antminer S5 is an excellent next step and with power consumption levels low. The S6, when it comes out with multiple blades and a rack mount chassis, should be a beast if they go that route like they have in the past with their S2 and S4.  Yoshi the US Bitmain Sales representative told CCN.com at TNABC in Miami that the S6 may also be their next Gen chip though so time will tell which way they go.

The S5’s loud fan may turn off some buyers, but we replaced it with a Cooler Master jet flow that had a higher CFM and much lower volume at 48 dB. The change in fans also resulted in a drop in temps by 4C. Being winter and the temps below freezing in the CCN.com mining laboratory, we pushed the clock speed freq up and were able to get the S5 to a stable 1.41 th/s at 630 watts. Any higher the error rate would push from 1-3% to 6-8%.

The Antminer S5 also is a solid under clocking system able to drop just below 480 ways and still perform at nearly 1 th/s. This power saving feature is critical when BTC value dips are allowing you to still mine under clocked to save power costs yet at not so much of a hit performance wide to cost you too many satoshi’s.

Overall another excellent chip and miner from Bitmain. How long they can keep the crown of the fastest power to gh/s ranking will be tested soon as Spondoolies and BitFury are both due out with those next gen chips very soon. The Antminer is also priced aggressively as well making it a good purchase.

At TNABC in Miami CCN.com asked Yoshi a few questions about Bitmain and Hashnest as well as his take on Cloud Mining with the BTC value that had taken at dive at this point. When asked about Cloud Mining he was very clear that most miners have an EOL and if they are accelerated by lower BTC value they turn them off. He noted they also have rolled out the S4 in HashNest as a choice that would allow customers to run longer. Now that the BTC value is rising many of the current miners will remain profitable longer as well.

We also asked about extra-nonces support as many customers needed it to have the S5 run on multi pools like WestHash. At the time, Yoshi the S5 would be able to do them but they had not released the new firmware. Bitmain has now released the new firmware found here , and the miners are running great with this new ability. Hytekk has put up a guide on how to install the firmware and activate the extra nonce capability.

Thank you, Yoshi for the information and Hytekk for the handy guide for those who had not updated the firmware before or enabled the extra nonce feature. We will be doing a longer interview with Yoshi in the near future. Stay tuned.

Disclosure: Antminer S5 was purchased by the writer for review.