The Advanced Micro Devices (AMD) 486DX4 microprocessor is often referred to as an Intel clone, although it requires a lower internal voltage (3.3 volts), which enables the chip to operate at lower internal temperatures. To achieve higher clock speeds in the 486 processor series, Intel engineers increased the total number of transistors to 1.6 million and reduced the original 1.0-micron fabrication technology down to a finer 0.6 microns. AMD answered with its own improved 3-layer, 0.5-micron complementary metal oxide semiconductor (CMOS) fabrication technique, which resulted in chips that dissipates 2.6 watts at 100 megahertz or 3.2 watts at 120 megahertz clock speeds. Enhanced 486DX4 microprocessors from AMD, which feature 32-bit pipelined microarchitecture, support 8-kilobyte write-back (versus 16-kilobyte write-through) internal cache memory. This enables frequently accessed data and instructions to be stored in a high-speed, internal cache.