Due to the rising hashrate of the bitcoin network caused by the introduction of ASICs to the market, GPU mining Bitcoins has become impracticable. The hashrate of most GPU units is below 1GH/s, and as of 2014, some single ASIC units are able to reach speeds of over 1,000GH/s while consuming far less power than used by a GPU. The information in this table is preserved for historical interest, but does not include many GPUs which were released after the advent of ASIC mining. An application-specific integrated circuit (abbreviated as ASIC) is an integrated circuit (IC) customized for a particular use, rather than intended for general-purpose use. In Bitcoin mining hardware, ASICs were the next step of development after CPUs, GPUs and FPGAs. Capable of easily outperforming the aforementioned platforms for Bitcoin mining in both speed and efficiency, all Bitcoin mining hardware that is practical in use will make use of one or more Bitcoin (SHA256d) ASICs. Note that Bitcoin ASIC chips generally can only be used for Bitcoin mining. While there are rare exceptions - for example chips that mine both Bitcoin and scrypt - this is often because the chip package effectively has two ASICs: one for Bitcoin and one for scrypt.