It has a language of 252 root instructions and with the reserved 4 bytes as prefixes, access to an additional 308 instructions. Although it lacks the raw processing power of processors like the Intel 80x86 or the [[Motorola 68000]] series, the Z80 is extremely useful for low cost control applications.
The Z80 has about 8500 transistors. To put it into perspective, 64KB of DRAM contains 524288 transistors, as 1 bit of DRAM needs 1 transistor. Fun fact: an Amstrad CPC equipped with a 4MB RAM expansion has 32 million transistors dedicated to RAM while the Z80 CPU still has only 8500 transistors.
The Z80 is mid-1970s technology while the 64KB DRAM is early-1980s technology and the 4MB DRAM is early-1990s technology.