Alpha was designed to replace 32-bit VAX complex instruction set computers (CISC) and to be a highly competitive RISC processor for Unix workstations and similar markets.

These microprocessors were most prominently used in a variety of DEC workstations and servers, which eventually formed the basis for almost all of their mid-to-upper-scale lineup.

PRISM was intended to be a flexible design, supporting Unix-like applications, and Digital's existing VAX/VMS software, after minor conversion.

A new operating system named MICA would support both ULTRIX and VAX/VMS interfaces on a common kernel, allowing software for both platforms to be easily ported to the PRISM architecture.

[9] Having watched the PRISM delivery date continue to slip, and facing the possibility of more delays, a team in the Palo Alto office decided to design their own workstation using another RISC processor.

After due diligence, they selected the MIPS R2000 and built a working workstation running Ultrix in a period of 90 days.

[11] As the meeting broke up, Bob Supnik was approached by Ken Olsen, who stated that the RISC chips appeared to be a future threat to their VAX line.

Another concept was a pure RISC system that would translate existing VAX code into its own ISA on-the-fly and store it in a CPU cache.

Unfortunately, all of these approaches introduced overhead and would not be competitive with a pure-RISC machine running native RISC code.

[12] The group then considered hybrid systems that combined one of their existing VAX one-chip solution and a RISC chip as a coprocessor used for high-performance needs.

These studies suggested that the system would inevitably be hamstrung by the lower-performance part and would offer no compelling advantage.

There appeared to be no compelling reason why VMS could not be ported to a RISC chip as long as these small bits of the model were preserved.

Two questions were raised: could the resulting RISC design also be a performance leader in the Unix market, and should the machine be an open standard?

When management accepted the findings, they decided to give the project a more neutral name, removing "VAX", eventually settling on Alpha.

[16] The PRISM's Epicode was developed into the Alpha's PALcode, providing an abstracted interface to platform- and processor implementation-specific features.

This included DEC's StrongARM implementation of the ARM computer architecture, which Intel marketed as the XScale processors commonly used in Pocket PCs.

The core of Digital Semiconductor, the Alpha microprocessor group, remained with DEC, while the associated office buildings went to Intel as part of the Hudson fab.

To ensure this, any architectural feature that impeded multiple instruction issue, clock rate or multiprocessing was removed.

A split register file was also determined to be more suitable for multiple instruction issue due to the reduced number of read and write ports.

Digital concluded that 32 registers was more suitable as it required less die space, which improves clock frequencies.

Since it is useful to obtain the most significant half, the Unsigned Multiply Quadword High (UMULH) instruction is provided.

Firstly, Digital had determined that the Alpha 21164 was already capable of performing DVD decoding through software, therefore not requiring hardware provisions for the purpose, but was inefficient in MPEG-2 encoding.

In 2003, the Alpha 21364 or EV7 Marvel was launched, essentially an EV68 core with four 1.6 GB/s[a] inter-processor communication links for improved multiprocessor system performance, running at 1 or 1.15 GHz.

In October 2001, Microway became the exclusive sales and service provider of API NetWorks' Alpha-based product line.

[6] Hewlett-Packard merged with Compaq in 2002; HP announced that development of the Alpha series would continue for a few more years, including the release of a 1.3 GHz EV7 variant named the EV7z.

However, the figures give a rough impression of the performance of the Alpha architecture (64-bit), compared with the contemporary HP (64-bit) and Intel-based offerings (32-bit).

On the other side, HP (PA-RISC) is also reasonably close to Alpha, but these CPUs are running at significantly lower clock rates (MHz).

DEC later produced Alpha versions of their Celebris XL and Digital Personal Workstation PC lines, with 21164 processors.

To assist third parties in developing hardware and software for the platform, DEC produced Evaluation Boards, such as the EB64+ and EB164 for the Alpha 21064A and 21164 microprocessors respectively.

The fastest supercomputer based on Alpha processors was the ASCI Q at Los Alamos National Laboratory.