Category Archives: Mining

Radeon R9 280X GPU & mining: preliminary results

Now that the excellent Radeon 7950 video cards have essentially become unobtainable, I’m getting a lot of questions from people about how to get the most out of the new Radeon R9 280X in terms of mining. I managed to get my hands on a few Sapphire 280X cards this past week, and have done a little bit of experimenting.

I’ll get around to updating my guide for the 280X at some point in the next couple weeks, but if you’re looking for a good starting point as far as cgminer and undervolting settings go, read on.

Radeon 7950 GPUs are becoming scarce

Many of you have contacted me recently asking for my opinion of x brand/model of 7950 GPU, given that some of the top choices from my mining hardware guide are sold out everywhere. Thought I’d throw up a quick post with some of the best alternatives for those of you that are looking to build a rig.

Yes, the Radeon 7950 is still the best GPU mining platform (and probably will be for quite some time), assuming you don’t have access to free electricity. Click “read more” for the list.

ASRock releasing mining motherboard

ASRock announced today that they’re releasing a motherboard that is specifically targeted at GPU miners. Although ASRock is marketing it as a “bitcoin mining” motherboard, it’ll likely prove far more interesting to scypt-based coin miners (litecoin, etc), as bitcoin mining is now pretty much the realm of ASIC-based hardware.

The H81 Pro BTC has 6 PCIe slots, which means it will support a maximum of six GPUs. The remarkable feature is the inclusion of two molex power connectors on the motherboard, which should prevent the need for powered risers entirely.

It’ll be interesting to see how the board is priced.

PSA: Don’t use GPUs to mine Bitcoin!

USB ASIC miner

A couple of these ~$20 USB ASIC miners are just as effective as a $300 GPU when it comes to SHA-256 (Bitcoin) mining.

With the recent price surge of Bitcoin, I’ve been getting a few messages from people asking about the viability of building a GPU-based rig to mine bitcoins directly. Don’t do that! GPU mining is only suitable for scrypt-based cryptocurrency (Litecoin, etc).

If you’re interested in mining Bitcoin, then you absolutely must use ASIC hardware if you hope to turn a profit. For example, six of these will mine as many bitcoins as a full-size triple GPU rig, and they’ll do it at less than 10% of the cost and power consumption (remember to pick up a USB hub if you plan to run a few, and perhaps a small fan or two—they run fairly hot)!

The downside to ASIC-based mining is that the hardware cannot be re-purposed once it becomes obsolete—and with the rapidly-increasing Bitcoin mining difficulty, that will happen fairly quickly unless the price of the currency keeps pace. Remember that you can always mine scrypt-based coins with your GPUs and trade them for bitcoins on an exchange, as well.

Undervolting in Linux via modified video BIOS

Hex

Before VBE7: Creating custom vBIOS files meant manually editing hex and hoping for the best—yuck!

For a long time, I’ve held off on writing a guide about modifying your video BIOS for the purpose of lowering voltage. Undervolting has the potential to reduce power draw by about 50 watts per GPU, so it’s easy to understand the appeal—you’ll see a significant savings on your electricity bill if you’re running a 3×7950 rig (like the one in my guide) 24/7. Unfortunately, the AMD Radeon drivers in linux don’t allow voltage control, so the only current way to lower voltage below manufacturer-specified levels in linux is to modify your video card’s BIOS.

In the past, such a hack involved manually editing your vBIOS file by hand, using a hex editor. Most folks hesitate to make such a modification, as performing the edit can be tricky if you’re not familiar with hexadecimal—and a mistake can mean a bricked GPU. Due to the potential danger I had decided not to post a guide about manually modifying your vBIOS ROMs. After all, nobody wants to be left with a $300 paperweight after inadvertently trashing their video card.

Enter VBE7, a GUI-based vBIOS editor for Radeon 7xxx series GPUs. Now anyone can easily make changes to their vBIOS without having to muddle around in a hex editor, praying they get things right. I’ve been testing VBE7 for a few days now, and it appears to work brilliantly. Read on for my guide on creating your own custom power-saving vBIOS!

CryptoBadger’s custom mining rigs $76 off until 7/4

CryptoBadger's custom mining rigsI just got a shipment of riser cables in, for those of you who were interested in purchasing a custom rig from me. I’ve also decided to take $76 off the purchase price of each rig until July 4th (or until I run out of risers again!), in celebration of Independence Day here in the US!

Click here for information on purchasing one!

AMD 7990 GPUs available at Amazon

Amazon has some of the new Radeon 7990 video cards available. These behemoths are essentially two 7970 GPUs on one card, but require less power than two individual 7970s. That package should make it quite a good choice for cryptocurrency mining, if you can stomach the price tag (although it currently comes with vouchers for 8 free games, which defrays the cost a bit if you choose to resell them).

Anyone tried mining with one of these yet? The speed/power consumption ratio should be comparable to a 7950 (the current king of mining), but with a huge advantage in potential GPU density.

WeMineLTC litecoin pool possibly underpaying miners

If you use WeMineLTC as your litecoin mining pool, you should take a careful look at your earnings. There have been an increasing number of reports from miners that the pool is underpaying by ~30%, either because the operators are intentionally skimming, or because the pool is misconfigured. You can read more in this Reddit thread, or here on the Bitcointalk forums.

I have never used WeMineLTC, so I can’t comment personally. Mining pool scams certainly aren’t unheard of, so regardless of which pool you choose, make sure to keep an eye on your earnings to ensure that they’re in line with expectation (don’t forget to account for the pool’s fee, any pool or miner downtime, and internet latency).

Update 5/29: Apparently there was a vulnerability in WeMineLTC’s pool code that was exploited by some users to steal coins. It has been patched as of today.

CGWatcher: A watchdog for cgminer

CGWatcherEver wish that you could keep an eye on your miners 24/7? Maybe you’ve had cgminer inexplicably stop mining in the past, or you’re currently testing out settings that you’re not sure are stable—whatever the reason, it’d be nice if you immediately knew about issues that required a cgminer restart.

Enter CGWatcher, a tool that will keep an eye on cgminer for you. CGWatcher monitors several cgminer outputs, and will automatically restart cgminer whenever an issue is detected (e.g.: a dead/sick GPU, no submitted shares for the past x minutes, hashrate below a set threshold, etc).

It’s a great little tool, and I highly recommend it—especially if you don’t have your miners at a point where they’re completely stable yet. You can read more about CGWatcher (and download it) at the author’s website.

The altcoin explosion… and how to profit from it

AltcoinsIf you’re following the cryptocurrency mining scene at all, you’ve probably noticed that there are digital currencies other than Bitcoin and Litecoin. Quite a few of them, actually. Bytecoin, Terracoin, PPCoin, Feathercoin, Freicoin, Novacoin… the list goes on and on, and it seems like there is a new addition weekly.

The sad reality is that virtually all of these coins bring nothing significant to the table when compared to Bitcoin. The Bitcoin code is open-source, which means that anyone with a few hours of time on their hands can make some minor adjustments and fork off a brand new virtual currency that is nearly identical to the original in everything but name.

But why would somebody make a near-clone of Bitcoin? Why would anyone use a knock-off currency when they could just use bitcoins instead? Read on for some answers about altcoins, and how you can profit from them as a miner.