The main producers of heat in both laptop and desktop is of course the processor. Beginning with the 8086 16-bit Intel microprocessors that nearly 30,000 transistors, the 80286, the 80386 32-bit microprocessor. This i386SX was first produced 275,000 transistors as a stripped down version to reduce the i386DX with a 16-bit external bus circuit overhead on the PC. Another version, now specifically designed for laptops, the circuit had i386SL save electricity,such as sleep mode, etc. This brought the transistor count to around 3x that i386DX.