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.

Today’s Senate hearing on Bitcoin: surprisingly reasonable

This afternoon’s Senate hearing regarding the future of Bitcoin and other cryptocurrencies went quite well. In fact, the Washington Post is calling the hearing a “Bitcoin Lovefest.” It seems that many of the top US government officials recognize the potential value of Bitcoin, as well as the danger of stifling innovation by attempting to regulate it.

If you weren’t able to watch the hearing on C-SPAN, you can find an excellent summary on reddit of the main points made.

No doubt the positive hearing outcome helped drive today’s tremendous BTC price growth.

Please be reachable if you purchase one of my custom mining rigs!

Just a quick note that I have been unable to reach a couple of the people that have purchased a custom mining rig from me over the past few days.

I need to be able to reach buyers so that I can gather mining pool worker credentials and some other information in order to set up each rig up properly—as well as give myself some peace of mind that the person on the other end of the transaction isn’t trying to scam me, which is unfortunately always a possibility with Paypal. If I’m unable to reach you after a few days of attempts, I’ll simply cancel your order and refund the purchase price of the rig to you.

If you’ve purchased a custom rig from me recently and we haven’t yet established a dialog, please contact me ASAP.

On a related note, it’s getting difficult for me to locate enough quality parts to build these things as fast as the orders are coming in, given the recent upward price explosion of cryptocurrency. If you’ve been putting off buying or building a mining rig, you may not want to wait too much longer.

Max Keiser predicts $50+ for Litecoin

Looks like Max Keiser agrees with my long-term prediction for Litecoin. He tweeted this morning that he expects Litecoin to hit $50.

LTC hit a record high earlier today, reaching nearly $6.50 before pulling back a bit.

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.

On mining profitability

With the price of litecoin and bitcoin on the rise, I’ve received a tremendous amount of email over the past couple weeks from people wanting to know whether or not it’s “too late” to get into mining. Or how soon one can expect to break even on a new mining rig purchase. Or what my predictions are for the future value of cryptocurrency in general. I’ve responded to many of you already, but it probably makes more sense to post something here publicly.

Full disclosure: I don’t have a crystal ball. I have no idea what the future holds with regard to bitcoin or litecoin valuation. There are far to many variables and unanswered questions—especially on the regulation front—to make predictions with a high degree of confidence. However, I’d be happy to share some observations that I’ve made over the past few years, and offer my 2 cents in a general sense. Read on if you’re interested.

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


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!

bitcointalk.org forums hacked, user accounts for sale

The popular cryptocurrency forum bitcointalk.org (the site is currently down) was breached by hackers yesterday. Apparently the hackers were able to gain access to the site database and obtain the complete list of ~150,000 user accounts, along with each user’s hashed password. The hackers are now offering the list up for sale to any interested buyer for 25 BTC. There is some more information in this reddit thread.

If you had an account on the bitcointalk forums, make sure that you’re not using the same login/password combination anywhere else. While the user passwords were hashed, they’ll likely be cracked at some point.

Here is a copy of the email that I (and presumably every other bitcointalk forum user) received from the bitcointalk admins earlier today:

Unfortunately, it was recently discovered that the Bitcoin Forum’s server
was compromised. It is currently believed that the attacker(s) *could* have
accessed the database, but at this time it is unknown whether they actually did
so. If they accessed the database, they would have had access to all
personal messages, emails, and password hashes. To be safe, it is
recommended that all Bitcoin Forum users consider any password used
on the Bitcoin Forum in 2013 to be insecure: if you used this
password on a different site, change it. When the Bitcoin Forum
returns, change your password.


Passwords on the Bitcoin Forum are hashed with 7500 rounds of
sha256crypt. This is very strong. It may take years for
reasonably-strong passwords to be cracked. Even so, it is best to
assume that the attacker will be able to crack your passwords.
The Bitcoin Forum will return within the next several days after a
full investigation has been conducted and we are sure that this
problem cannot recur.


Check http://www.reddit.com/r/Bitcoin/ and #bitcoin on Freenode for
more info as it develops.


We apologize for the inconvenience.

mcxNOW paying out interest on cryptocurrency deposits

Yesterday, mcxNOW—a cryptocurrency exchange supporting Bitcoin, Litecoin, and several other altcoins—started paying its users interest on their digital deposits. The interest rate is variable and dictated by the trading fees collected by the exchange.

It’s an interesting move, and if it’s successful in significantly growing mcxNOW’s user base, you can bet that other exchanges will launch similar programs. Remember that while earning interest on your deposits may feel very bank-like, you’d be wise to treat online exchanges as your own personal cryptocurrency piggy banks at your own risk.