When building a GPU based mining rig, research shows there is a lot of misinformation going around that makes it difficult to decide what to purchase. This has a lot to do with the nature of mining. Its something that just about anyone with a little cash can do, if they can follow directions from a blog like The Geek Pub. These people post in forums and all over the internet in blog comments. In many cases their opinions and advice are simply uninformed at best, and blatant lies at worst. Choosing the best power supply for mining cryptocurrency on a GPU is one of the areas where this becomes clearly obvious. You’ll see chants of “You need multiple power supplies.” or “You need a 2000 watt power supply.” Read along and we’ll get to the bottom of this quickly!
Understanding GPU Mining Power Supply Needs
It’s very common to think that a GPU miner needs massive amounts of electricity to operate. And it is true that it needs a lot. It’s also true that there is more than meets the eye when thinking about power supply wattage numbers. Indeed the power supply might be one of the most critical components for a mining machine, right next to the GPU itself. Here’s the good news: This is mostly a simple math equation that anyone can do.
Mining Power Supplies and Total Wattage
The first thing you need to do is understand the total wattage that your mining computer will draw. Add up the wattage of all of the components in your rig and see where that final number lands. The main concerns here are your processor, motherboard, and GPU cards. This however is where things can get really confusing. The wattage number on your processor is likely to read something as high has 95 watts, while the number on a card such as the NVIDIA GTX 1060 is likely to read as high as 200 watts when looking at the manufacturer specifications. With six GPUs you’re looking at 1295 watts!
Here’s where much of the confusion comes in. These are the maximum theoretical wattage numbers, under a perfect condition and full load. In your mining operation there is almost zero chance you will ever hit those numbers. As shown in the tour of my mining PC build, I run six GTX 1060 cards, each pulling about 95 watts at maximum load.
Let’s understand those two main factors:
Mining doesn’t use the Full Capacity of the GPU
Mining doesn’t use the full capacity of the card or even many of its components. Think about it. There are many components on the GPU designed to deliver video to a monitor. None of these components are even connected in mining operations. Much of the data bus of the card is idle most of the time. It’s the CUDA cores that are busy calculating hashes for the coin you are mining.
Over and Under-clocking Plays a Bigger Role than Many Think
While we overclock the memory core of the GPU, we under-clock just about every other component on the card. The core GPU clock can be under-clocked as much as -200 Mhz depending on the card. The power levels can be set as low as -65% on some cards. Other cards can be under-volted with literally no impact on performance.
These factors result in a GPU rated at consuming 200 watts at maximum theoretical load actually consuming only 95 watts during a mining operation! This is great news because your six GPU mining rig that calculated at 1295 watts, in actuality is only pulling about 520 watts in a mining operation. This same thing applies to almost every component on the board. That 95 watt CPU is likely only consuming 15 to 20 watts at idle (or mostly idle).
The world is over-subscribed. This is something many people miss completely and one of the reasons there is so much bad advise going around on the internet. It makes it really hard for the uneducated newbie to pick the best power supply for mining cryptocurrency. You will literally see people in the forums say “But your mining rig ‘might’ surge and you’ll burn out your power supply.” This is utter hogwash.
Walk out to your garage or go in your basement and look at your breaker panel. It probably says something on it like “200 amp panel”. A 200 amp is the most common panel installed in residential homes. The main breaker at the top of the panel will be a 200 amp breaker. This feeds the entire panel. Now take just a minute to add up all of the breakers in the panel. What? They add up to more than 200 amps don’t they? That’s nuts! Actually its called over-subscription. Your power company does this. Your Internet company does this too. I can assure you AT&T doesn’t have a terabit uplink to cover the 1000 gigibit connected homes in a a Gigapower neighborhood.
That’s because they know the odds of everyone doing something at once is infinitesimally small. The same thing is happening inside your mining rig! One card may surge for a second, the CPU may surge for a second, etc. But not all at once.
Over-sizing you Power Supply for Efficiency
There is a good reason to over-size your mining power supply though! And that comes in the terms of efficiency. A power supply performs most efficiently when running at about 80% load. This allows the fans to spin down, and the the power supply will generate less overall waste heat. Slightly over-sizing your mining power supply can save you some cash on your electric bill resulting in a more profitable miner, assuming you don’t spend so much on the supply as to eat those savings. If your rig tops out at 520 watts, spring for 850 watt supply to keep things efficient and give some wiggle room.
A Smart Power Supply is Great for Mining
Another thing to consider is getting a smart power supply. This is two fold. Mining rigs usually operate unattended without a keyboard, mouse, or monitor attached. Being able to remotely monitor the power supply wattage and temperature levels is a great feature to have. Additionally, as you add components to the rig over time or upgrade older components you can make sure you are still within the limits of your supply. Some manufacturers report this data through a protocol called LINK. Smart power supplies will add a little cost your ROI equation, but in my opinion not enough to outweigh the benefits.
Modular Mining Power Supplies Rule
Another great feature to look for in a power supply is modularity. A fully modular power supply means that the cables are not permanently attached to the power supply. This allows you to use different cables for different components. If you don’t have a certain component on your rig there is no cable hanging loose and unused that needs to be dealt with. Simply leave that cable in the box for future use.
Modular power supplies generally come with multiple cables for different types of devices. This means you can select exactly the modular cable (and number of cables) you need to build out your rig. I always recommend a modular power supply when you can afford one.
Best Power Supply for Mining Cryptocurrency
So let’s list my top 4 picks for the best power supplies for mining! These power supplies should work in 99% of mining rigs being built today. If you are planning to use a super power hungry card like a Titan V, then more planning is likely required. Check out my article on selecting the right mining GPU for help.
#1 – The Corsair HX1000i
The Corsair HX1000i is a 1000 watt smart power supply with LINK technology. It’s incredibly quiet, super efficient, and has plenty of modular ports for running PCIe risers, GPUs, and just about anything else you need it to.
#2 – EVGA SuperNOVA 1000 G2
Rocking in at number two on our list of the best power supplies for mining is the EVGA SuperNOVA 1000 G2. This power supply is fully modular, gold certified, and comes in at 1000 watts. What brings it to number two on our list is that it costs slightly more than the HX1000i and does not offer smart features. Get it here!
#3 – The Cooler Master V1000
The Cooler Master V1000 comes in at number 3 on our list. It’s a great compromise between these other supplies. It’s fully modular, gold certified, and clocks in at great value price! Its only downside is that it is not a smart power supply. Get it here!
#4 – The Rosewill Gaming Power Supply
The Rosewill Gaming Power supply is a bronze certified power supply clocking in at the lowest price on the scale. It’s perfect for the budget conscious miner. It’s 1000 watts and meets the requirements of most mining rigs. It however, isn’t fully modular. You’ll have to deal with a giant octopus of cables hanging out the back, even if that cable is unused. Additionally it is not a smart power supply.
If clean power and budget are all you need, the Rosewill is the way to go. Get it here!