The registers, memory bus, data bus on x86 architectures are 32 bits while this is 64 bits on 圆4. 圆4 came as an extension of the existing x86 architecture.
#X64 vs x86 difference 32 bit
X86 instruction set architecture is 32 bit while 圆4 instruction set architecture is 64 bits.
#X64 vs x86 difference 64 Bit
That is, a data bus of 64 bit can parallel transmit 64 bits while the x86 architecture that has a 32 bit bus can only parallel transmit 32 bits. 圆4 can parallel transmit larger size data along the data bus.Therefore, 圆4 can handle computation of larger integers much faster, as there is no necessity to use several registers in such case to split the value and store as in x86. Values that can be stored in a register, in a 圆4 system, is larger than a values that can be stored in a x86 based register.圆4 is an expansion of x86 therefore, it is much improved and powerful than the old x86.But, on 圆4 systems, this limit is huge, which is 2 64 bytes. x86 has a limitation on maximum addressable memory that is an upper limit of 4 GB ( 2 32 bytes).But 圆4 has 64 bit registers, 64 bit memory bus, and 64 bit data bus. Processors with x86 instruction set architecture, therefore, has 32 bit registers, 32 bit memory bus, and 32 bit data bus.(First x86 processors were 16 bit but, in later processors, an extension to 32bit was done). But 圆4, which came as an extension to x86, was introduced by AMD. x86 emerged from the famous Intel 8086 processor and, therefore, x86 was introduced by Intel.x86 was introduced in around year 1978 while 圆4 came up more recently in year 2000.Some important thing to emphasize is that this 圆4 architecture is still backward compatible with the old x86 instruction set.Ħ4 bit processor What is the difference between x86 and 圆4? Currently, all Intel processors such as Core i3, Core i5 and Core i7 use this 圆4 architecture. With Intel Core processors that started from Intel Core 2, Intel started using this architecture in their processors. Then Intel also adopted this architecture. AMD K8 was the first processor that implemented this 64 bit architecture. Now 2 64 distinct values can be addressed and this gives a huge upper limit on the possible maximum memory. With the 64 bit architecture, all registers became 64 bits and the memory bus and the data bus also became 64 bit. This AMD64 or 圆4 architecture is also known under the name x86_64. 圆4 is another name given to this AMD64 architecture. This was introduced under the name AMD64. AMD, in around year 2000, introduced such specification that extended the x86 architecture to 64 bits. In order to overcome this, further extensions were done to the x86 architecture. 2 32 bytes are equal to 4 GB and, therefore, x86 had a maximum addressable memory limit of 4 GB.
Anyway, in general, x86 refers to the 32bit architecture that evolved from a 16bit architecture that came up with the 8086 processor.Ī 32 bit system can represent only 2 32 distinct values and, therefore, the memory addressing is limited to that number of addresses. Then, the x86 instruction set was extended to a 64 bit instruction set and from this point onward it was called as 圆4, which we are going to discuss in the next section. Apart from that, many other improvements were also done.
But various other extensions happened to the x86 architecture, such as addition of instructions like MMX, SSE and SSE2. Then Pentium processors came as Pentium I, Pentium II, Pentium III, Pentium IV and all these followed a 32 bit architecture as well. Here, 32 bit means that all registers, memory bus, and data bus are 32 bit. With the introduction of 80386, the x86 instruction was extended to a 32bit system. Since all these processors end with the number 86, the instruction set architecture was identified by the name x86. Then later they introduced various processors such as 80186, 80286, 8036, and all were backward compatible with the original instruction set used in the 8086 processor. In 1978, Intel introduced the 8086 processor that was a 16 bit processor. X86 is an instruction set architecture introduced by Intel with the famous 8086 processor. Later other companies such as Intel also implemented that specification and this AMD64 is the one that is identified by the name 圆4. Then various extensions happened and, in 2000, AMD created the specification to extend the x86 instruction set to 64bit under the name AMD64. x86 is a world famous ISA introduced by Intel in 1978 with the 8086 processor. Instructions, memory addressing, registers, and many other architectural sections of a CPU are specified by the ISA. An instruction set architecture (ISA) is a very important term that applies to any CPU. The most important difference between x86 and 圆4 is that the former is the 32 bit architecture and the latter is the 64 bit instruction set architecture.