Original Link: https://www.anandtech.com/show/53

Intel Pentium MMX

by Anand Lal Shimpi on May 27, 1997 6:59 PM EST


A few months ago Intel gave the power user two options, a Pentium 200 for Windows 95 and a Pentium Pro 200 for Windows NT, nothing in-between and therefore leaving the power hungry user searching for a better processor solution from AMD and Cyrix. Intel satisfied the market's demand by releasing a Pentium Pro-like Pentium successor which boasted a larger L1 cache, a more advanced core, and 57 brand new additions to the x86 instruction set, dubbed MMX. Originally thought as standing for Matrix Math eXtensions Intel quickly denied that the buzz-word MMX meant anything at all and was nothing more than a copyrighted trademark. Regardless of what the term MMX really was intended to convey, Intel had regained the attention of the market with a shiny new toy that inspired a few happy lab technicians to "play that funky music" =)

Lets take a look at what makes the Pentium MMX a better choice than the Classic Pentium and the big daddy Pentium Pro:

  • Its 32KB of L1 Cache is double the size of the Classic Pentium's and Pentium Pro's L1 Cache, giving it an excellent speed increase in real world applications

  • The Pentium MMX was the first processor to use the new split-rail voltage, with its core running at 2.8v the Pentium MMX made a mobile laptop design very simple and easy to implement

  • Taking after the Pentium Pro, the Pentium MMX has a highly advanced core, much more advanced than the Classic Pentium. It is because of this that a Pentium MMX-166 can outperform its 200MHz Classic brother.

Lets take a look at where the Pentium MMX is and where its going:

First Generation Intel Pentium MMX Series Microprocessor
Chip Name Clock Speed Bus Speed x Multiplier Fab. Size
Intel Pentium MMX 166 166MHz 66 MHz x 2.5 0.35 micron
Intel Pentium MMX 200 200MHz 66 MHz x 3.0 0.35 micron

Intel dazzled us all, for the most part, by introducing a whopping 2 new chips!!! As I mentioned earlier, the Pentium MMX's low voltage requirements made it ideal for a mobile environment. Sure enough, weeks after the release of the desktop Pentium MMX a mobile version was on the market:

First Generation Intel Mobile Pentium MMX Series Microprocessor
Chip Name Clock Speed Bus Speed x Multiplier Fab. Size
Intel Mobile Pentium MMX 150 150MHz 60 MHz x 2.5 0.35 micron
Intel Mobile Pentium MMX 166 166MHz 66 MHz x 2.5 0.35 micron

By dropping the clock speed to 150MHz, Intel was able to release a mobile version of their killer Pentium MMX without sacrificing any of the excellent qualities of it. As if that wasn't enough Intel went ahead and released a new mobile Pentium MMX processor, this time clocking in at an amazing 200MHz.

Second Generation Intel Mobile Pentium MMX Series Microprocessor
Chip Name Clock Speed Bus Speed x Multiplier Fab. Size
Intel Mobile Pentium MMX 200 200MHz 66 MHz x 3.0 0.35 micron

Originally planning to end their Socket-7 line of processors at 200MHz, however AMD surprised us all with their K6 and Cyrix demanded attention with their 6x86MX so Intel had no choice but to release a higher clock speed Pentium MMX, this time aimed at competing with the 6th generation Socket-7 CPUs that were popping up in the market. Although it clearly had no chance of matching the business performance of any of the 6th generation chips, the Pentium MMX still has some life left in it.

Second Generation Intel Pentium MMX Series Microprocessor
Chip Name Clock Speed Bus Speed x Multiplier Fab. Size
Intel Pentium MMX 233 233MHz 66 MHz x 3.5 0.35 micron

As with the AMD K6, Intel's Pentium MMX 233 uses an internal clock multiplier designed to activate everytime a 1.5x clock multiplier is set on the motherboard, therefore by setting your jumpers to the 66MHz x 1.5 setting you get a 3.5x clock multiplier resulting in a 233MHz clock speed. And although Intel claimed that the Pentium MMX would end at 233MHz they already started working on a fab. shrink for the upcoming 266MHz Pentium MMX, codenamed Tillamook.

Here are some of Intel's plans for the future of the Pentium MMX line:

Third Generation Intel Pentium MMX Series Microprocessor
Chip Name Clock Speed Bus Speed x Multiplier Fab. Size
Intel Tillamook 266 266MHz 66 MHz x 4.0 0.28 micron
Intel Mobile Tillamook 233 233MHz 66 MHz x 3.5 0.28 micron
Intel Mobile Tillamook 266 266MHz 66 MHz x 4.0 0.28 micron

As you can tell, Intel does have some future plans for the Pentium MMX, by shrinking their fabrication techniques to 0.28 micron or lower they will be able to produce low power solutions with support for mobile systems at clock speeds up to 266MHz. Personally, I doubt Intel will end the line at 266MHz, we should be able to expect 300 and 333MHz versions of the Tillamook sometime next year which is the release date for the Tillamook (Q1-98). Whether or not it will run at a 100MHz bus speed and if it will be able to top AMD's K6/266 and 300 will be questions that will remain unanswered until next year.

Windows 95 Performance of the Intel Pentium MMX - Business Winstone 97

Chip Business Winstone 97
Intel Pentium MMX - 200 52.0
Intel Pentium MMX - 208 (theoretical) 55.1
Intel Pentium MMX - 225 (theoretical) 54.8
Intel Pentium MMX - 233 54.4
Intel Pentium MMX - 250 (theoretical) 57.2
Intel Pentium MMX - 266 (estimated) 56.6
Intel Pentium MMX - 300 (estimated) 60.1

Raw Intel Pentium MMX Performance - Wintune 97 Scores

Chip Millions of Instructions per Second (Integer) Millions of Floating Point Instructions per Second (FPU)
PMMX-233 435 133
PMMX-262.5 499 149
PMMX-290.5 537 166

Intel Pentium MMX Windows 98 Real World FPU Tests - Truespace3 Render Times

Chip Render Time (lower is better)
Intel Pentium MMX - 290.5 11:23s

Like the AMD K6, the Pentium MMX also experiences a slight performance hit when running Windows 98 compared to when running windows 95. This could be attributed to the weaker 32 bit performance of these two chips when compared to their 16 bit performance, although I wouldn't get too alarmed since the degraded performance is barely noticeable, Win98's new interface takes most of the attention away from it =)

Intel Pentium MMX Real World FPU Tests - Truespace3 Render Times

Chip Render Time (lower is better)
Intel Pentium MMX - 233 14:11s
Intel Pentium MMX - 262.5 12:14s
Intel Pentium MMX - 290.5 10:83s

Intel Pentium MMX Gaming Performance - WinQuake Framerates

Resolution Intel Pentium MMX - 233
320 x 200 46.9 fps
512 x 384 21.5 fps
640 x 400 20.9 fps
640 x 480 18.1 fps
Resolution Intel Pentium MMX - 262.5
320 x 200 56.2 fps
512 x 384 24.4 fps
640 x 400 23.5 fps
640 x 480 20.4 fps
Resolution Intel Pentium MMX - 290.5
320 x 200 61.9 fps
512 x 384 25.9 fps
640 x 400 25.9 fps
640 x 480 22.4 fps

Log in

Don't have an account? Sign up now