x86 VS x64: The Key Differences Explained

The terms x86 and x64 are fairly rare to hear. Modern computing machines like desktop PCs and smartphones run on a 64-bit architecture as a standard. They are more commonly labeled as x86-64, AMD64, or ARM64. During the transition from 16-bit and 32-bit systems to 64-bit systems, the differences between the computing systems were clear and simple. 64-bit systems contained significantly more RAM, memory, and processing power than the 32-bit predecessors.

These improvements are due to the doubling of the size of instructions the microprocessor can handle. AMD sought to displace Intel as the lead in processor manufacturing. It wasn’t long before Intel adopted the new 64-bit ISA as well. As the improved ISA took over, software applications were optimized to take advantage of x64’s improved efficiency. The remnants of these changes can still be seen when acquiring certain software like Java or visual studio. The download page on their respective websites offers not only different builds for various operating systems but also both a 32-bit and 64-bit version.

Today, any computer, tablet, or smartphone purchased new will come pre-installed with an OS that works on a 64-bit system regardless if the product uses Linux, macOS, Windows, or Android. Aside from very specific or proprietary solutions, it is recommended to use 64-bit systems and 64-bit software. Luckily, this is a simple task as modern software may only be available as a 64-bit application. On Windows systems, applications are separated into two different ‘Program Files’ folders. One is exclusively for 32-bit applications (‘Program Files(x86)’). This is because x86 applications can be run on x64 ISA systems making x64 the better option overall.

x86 VS x64: Side by Side Comparison

	x86	x64
What It is	Instruction Set Architecture	Instruction Set Architecture
Primary Use	Define processor management and instruction execution	Define processor management and instruction execution
Name	x86(32-bit) ISA	AMD64
Conceived	1978	1999
Technical Committee	Intel Corporation	AMD
Influential Developers	Intel Corporation	AMD
Open Format	Yes	Yes
Technologies Influenced	CPUs, RAM, motherboards, and most internal components	CPUs, RAM, motherboards, and most internal components
Initial Release	1978	1999

Computer systems have advanced rapidly over the last few decades. It is mostly due to a culmination of several competing technologies. As processor manufacturers developed better and faster chips, the processors became physically different in form and size from other designs. This, in turn, meant that newer components and older components may be incompatible.

This isn’t a new problem, nor was it unforeseen. In fact, most compatibility issues with technology are handled by the developers themselves. After all, who wants to buy a product that requires the user earns a degree in order to understand how to use it?

x86 and x64 are what are known as instruction set architectures (ISA) used by Intel as a standard for their microprocessors. ISA’s define how a processor manages and executes instructions from the OS and applications.

In fact, the name x86 is short for Intel’s 8086 microprocessors. The first series were 16-bit processors, but x86 gradually developed into both 16-bit and 32-bit instruction sets. The success of this system spread throughout the computing landscape.

x86 never stopped being developed. By 1999, a new series of 64-bit instructions built on the x86 architecture was being developed by both AMD (AMD64). The new series of instructions doubled the integer count of x86. This meant that x64 held a much larger virtual address space and physical address space. x86 is only able to manage 4 GB of RAM while 64-bit systems can address up to 256 TiB of RAM.

x64 and AMD64 also allow instructions to reference data in relation to the instruction pointer. This allows code to be position-independent. This allows applications to make better use of shared libraries for a faster and more efficient load during runtime. The increased ability of 64-bit architecture promoted adoption by Intel and later by ARM processor manufacturers as ARM64.

Here’s a quick feature list for each:

x86 32-bit Features:

• Uses Complex Instruction set computing Architecture (CISC)
• Complex instruction take many cycles to complete
• Prioritizes hardware over software for performance.
• Uses registers to manage hardware and relies on physical components to make up for low memory.
• Designed with fewer pathways and can use complex addresses
• Uses software DEP
• Limited to 4 GB of RAM

x86-64 64-bit Features:

• Larger virtual address space
• Large files can be processed simultaneously on multiple address spaces
• Support for up to 256 TiB of RAM and memory space
• Instructions are more efficiently and effectively loaded
• Supports hardware DEP
• Backwards compatible with 32-bit programs

x86 VS x64: 6 Must Know Facts

• x86 (32-bit) ISA systems only support up to 4 GB of RAM and can only transmit 32-bits of information. These are the two limiting factors that created the need for x64. At one time, it was thought that there would be no need for more than 4 gigabytes of RAM. Today, most devices come with a standard of 8 GB of RAM even smartphones and tablets.
• x64 was an improvement on the x86 ISA created by Intel but was actually made by AMD. While AMD chose to make the naming convention similar to Intel at the time, this was not because Intel had a hand in its creation. AMD was responsible for the creation of the 64-bit ISA that is now a standard. They chose to name the system AMD64 or x86-64 as a way to keep it simple for the market.
• 32-bit is still preferred for audio. While 64-bit is better than 32-bit, audio producers still tend to use 32-bit audio due to easier access and compatibility. In some cases, this is due to aging audio equipment that still performs well. 64-bit audio is more typical when the producer requires a series of post-processing tools and plug-ins to transform the sound.
• 64-bit ISA can theoretically support 16000 Petabytes of RAM. However, Windows limits maximum RAM to 2TB, and macOS limits RAM to 128GB. Fortunately, very few have the need for more than 16 GB of RAM.
• x86 is only truly required for legacy devices. While you may be curious as to what the differences between x86 and x64 are, you will likely never require anything other than x64 systems. This is because the only need to run in x86 is for aging devices that can not be updated or no longer have support.
• x86 assembled code always executes as a 32-bit code. Programmers using visual studio or Java need to know that compiling code as 32-bit will only allow the program created to run in 32-bit mode. This means it will limited in the same way a 32-bit system would be when it comes to resources. If the system the code is run on is 64-bit, the code will execute faster but still only have access to 4 GB of RAM and 32-bit ISA. This includes the visual studio or Java compiler that may be in use. If the compiler is programmed to run 32-bit, then the software will be locked to 4 GB of RAM.