[1][2] The 6x86 was made as a direct competitor to Intel's Pentium microprocessor line, and was pin compatible.

During the 6x86's development, the majority of applications (office software as well as games) performed almost entirely integer operations.

So, to optimize the chip's performance for what they believed to be the most likely application of the CPU, the integer execution resources received most of the transistor budget.

The M2 would also have some of the same features as the Intel Pentium Pro such as register renaming, out-of-order completion, and speculative execution.

[15] In March 1997 when asked about when the M2 line of processors would begin shipping, Cyrix UK managing director Brendan Sherry stated, "I've read it's going to be May but we've said late Q2 all along and I'm pretty sure we'll make that.

They were sold by TigerDirect and had a 12.1in DSTN display, 16 MB of memory, 10x CD-ROM, 1.3 GB hard disk drive, and cost $1,899 for the base price.

[18] Later by the end of May 1997 on the 27th, Cyrix said they would announce details of the new chip line (6x86MX) the day before Computex in June 1997.

Cyrix hoped to ship tens of thousands within June 1997 with up to 1 million by the end of the year.

[22] They had slightly better floating point performance, which cut adding and multiply times by a third, but it was still slower than the Intel Pentium.

[25][26][27] National Semiconductor was not interested in high performance processors but rather system on a chip devices, and wanted to shift the focus of Cyrix to the MediaGX line.

[37] In May 1999 National Semiconductor decided to leave the PC chip market due to significant losses, and put the Cyrix CPU division up for sale.

[38][25] VIA bought the Cyrix line in June 1999, and ended the development of high performance processors.

[42] However, the MII was still available for sale until mid/late 2003, being shown on VIA's website as a product until October, and it still saw use in devices such as network computers.

[45] However, it continued to use native x86 execution and ordinary microcode only, like Centaur's Winchip, unlike competitors Intel and AMD which introduced the method of dynamic translation to micro-operations with Pentium Pro and K5.

The lack of full P5 Pentium compatibility caused problems with some applications because programmers had begun to use P5 Pentium-specific instructions.

One of the main features of the P5/P6 FPUs is that they supported interleaving of FPU and integer instructions in their design, which Cyrix chips did not integrate.

The 6x86's and MII's old generation "486 class" floating point unit combined with an integer section that was at best on-par with the newer P6 and K6 chips meant that Cyrix could no longer compete in performance.

This was primarily caused by their higher heat output than other x86 CPUs of the day and, as such, computer builders sometimes did not equip them with adequate cooling.

Another release of the 6x86, the 6x86MX, added MMX compatibility along with the EMMI instruction set, improved compatibility with the Pentium and Pentium Pro by adding a Time Stamp Counter and CMOVcc instructions respectively, and quadrupled the primary cache size to 64 KB.

6x86MX / MII was late to market, and couldn't scale well in clock speed with the manufacturing processes used at the time.