As difficulty and hash rates continue to rise, cryptocurrency mining offers the promise of spoils for those who persevere.

Case in point is the story of Dave Carlson, who went from 30 GPU rigs to an advanced mining operation capable of making millions.

It seems decentralized, math-based currencies are on the up, and increasing amounts of miners are hashing away, powering these globe-spanning payment networks.

With this in mind, here’s a look at the top mining stories that have surfaced since our last round-up.

Wallet hardware designer TREZOR exhibited a public demo of its product this month at the Bitcoin Exchange Berlin (BXB), a free event in the city that aims to educate the public about the currency.

The company began taking preorders for the wallet last summer with the aim to start shipping the devices in January. However, TREZOR has stated that it is still working out software bugs and refining case production.

Cloud Hashing

, which offers bitcoin-mining-as-a-service, is preparing to increase the amount of hashing power it provides. By the end of this month, the company expects to reach 2.5 PH/s per second.

David Gilbert of the International Business Times estimated that would equate to $20m in block rewards per month, although those numbers could quickly decline if bitcoin's difficulty continues its upward march.

The company is also rolling out a promotion for Mt. Gox victims via the Mt. Gox customer relief effort which offers prospective Cloud Hashing customers discounts on mining packages.

The rates stand at $8 per gigahash for customers who can verify they had an account with Mt. Gox by showing email correspondence or other documentation.

Netherlands-based Mining Asics Technologies B.V. has opened up preorders for its line of Scrypt-based miners. The company is taking 35% deposits for a lineup that includes both FPGA and ASIC Scrypt miners.

At the bottom end of the spectrum is the 10 MH/s 180W Platinum 1 FPGA Scrypt miner which costs €2,999. For the more sophisticated crowd, there is the top-end 200 MH/s 3KW Excalibur 3 ASIC Scrypt Miner for €14,999.

Mining Asics Technologies sells these as completely standalone mining units: there's no need for a host as the miners come with Linux preinstalled. Additionally, a web interface allows users to access the system, and the company says that it will provide support for CGMiner.

CEX.io

, the company associated with the GHash.io mining pool, offers users a marketplace for the supply and demand of gigahashes.

The company is offering an interesting idea: it takes gigahashes and uses it as a trading pair against bitcoin in the form of GHS/BTC. The exchange is leveraging the power of its pool to allow for trading of bitcoin for gigahashes of power.

CEX.io is also selling futures contracts so that miners can hedge against risk. It is currently selling contracts for both April and May.

Scrypt mining is fast becoming a pursuit that requires careful planning. Thus, building rigs on a custom frame has become a popular choice for miners.

The Riggit V9 mining frame from Crypto Think Tank is a project design that provides spacing and power accommodation, but leaves the framing open to customization.

The Riggit V9's aluminum body can support up to eight cards, weighs 0.5 kilograms and is constructed for optimum airflow. It's designed to work best with two power supply units and has various screw placements for different configurations. The frame is available for $99.99 in Canadian dollars from NCIX.

GPU altcoin mining is really the only option left for the everyday mining enthusiast with limited means.

The good news is that AMD seemingly has solved some previous supply problems. It's selling Radeon R9 280 GPUs around a $279 price point, which is much lower than previous prices, which seem artificially inflated due to high demand.

Hashes per dollar spent are pretty important numbers right now, so the 270x might be a better deal electricity-wise.

On the subject of power consumption ... electricity usage is always on the mind of the cryptocurrency miner. The lower the electric cost, the better the mining yield.

MyRigSpace

, a new company located in Oregon, is focusing on that region's cheap hydro-generated electricity to market its hosting. "The days of hobbyist mining may be coming to a close," said Robert Van Kirk of MyRigSpace.

The company is taking advantage of the Portland, OR area electricity prices that are around 7 cents per kilowatt-hour.

They are also exploring plans to leverage even cheaper hosting options in Moses Lake, Washington, where prices are 1.73 cents per kilowatt-hour.

Los Angeles-area Zoomhash may be selling a scrypt GPU mining killer. They have a uniquely designed mining unit that is capable of hashing scrypt at 300 ~ 400 KH/s at 7W, according to its website.

It is selling Gridseed units in packs. For example, a set of 10 Gridseed miners can be had for $ 2,399.00, which would produce 3,000 ~ 4,000 KH/s of power.

The company claims that the units can also hash bitcoin, even given the current difficulty. But attempts to contact the company's CEO to verify this have not been successful. Nevertheless, what Gridseed is offering has value over traditional scrypt GPUs.

Got a cryptocurrency mining tip for future round-ups? Contact us.

Disclaimer: This article should not be viewed as an endorsement of any of the companies mentioned. Please do your own extensive research before considering investing any funds in these products.