Cyrix MediaGX and National Semiconductor Geode Information

Cyrix MediaGX and National Semiconductor Geode Information
Manufacturing Code Explanation

If you’re like me you have stared at the bottom of your MediaGX and asked “What the heck does that code mean?”
Well through hours of research, sifting through press releases and images as well as fab announcements and earnings reports The CPU Shack has been able to determine mostly what they mean. 🙂

Basically the MediaGX was made by IBM and by Nationalal Semiconductor. National had an overun contract with TSMC which I don’t have any idea whether it was actually used. National DID use TSMC technology in their plant in South Portland, Maine.

Here are the basic release dates:

Date Speed (MHz) February 20, 1997 133 (Original Release) June 6, 1997 150 June 30, 1997 166, 180 March 18, 1998 233 August 25, 1998 266

After the sale of Cyrix to VIA in 1999 National continued to make the MediaGX (or Geode by that time) in speeds of up to 333MHz. ANY MediaGX, GX1, GXm or GXLV with a speed over 333 is a fake. I have several of these and they are listed in my raw data table at the bottom of this page. IBM made MediaGX parts at least through April of 1999. They began production no later then March 1997 (which fits perfectly with the release date). National began production of the MediaGX in August of 1998. It was a pilot project at their Santa Clara facility and rapidly expanded to their other plants. The latest known made part that I have seen was in Spetember 2000. The Geode division was sold to AMD in 2003 so there areundoubtably later ones made.

The GX Processor is clocked in a rather strange way. It’s internal clock is based on the PCI bus. The PCI bus can be either 30MHz (150 or 180MHz) or 33MHz for all others. The jumpers (2 or 3 depending on revision) determine what to multiply this by. The maximum is 10, or 333MHz which is why there are no Geodes over 333MHz. The memory bus (you can call it the FSB if you like) is clocked at 1/3 the core clock. This means the memory can actually vary between 55MHz and 111MHz depending on what CPU is used.

National also created the GXLV which is the low voltage version of the GXm.
Released December 1999

National’s design team in Herzlia, Israel reworked the GXm into the GX1 which is a lower power version with more features. It was available in speeds of 200-333MHz with voltages of 1.6-2.2V (scaled with speed) It is made specifically for Internet Appliances. It has a different graphics subsystem and an updated I/O companion chip. Relesed in April of 2000 (preliminary silicon was made one year previous to that) it also was the first integrated Pentium class processor to operate at less then 1 Watt (0.8-1.4 Typical). This was obtained by shrinking the die to 0.18u. These CPUs are used in hundreds of different Single Board Computers as well as Internet Appliances.

Identification of Manufacturing Codes

IBM Produced	National Produced
GRFDDYWW**	FRAxxYWWDD
G = IBM	F = Fab that the Wafer was Produced in R Santa Clara, CA (R&D Fab) T South Portland, ME (TSMC Equipment?) V South Portland, ME
R = Die Revision B 0.x (Beta revision) A 1.x G 2.x J 3.x	R = Die Revision 3 3.x 5 5.0-5.4 J 2.x This is odd with the date code so high. (possibly TSMC pilot) 8 8.x (GX1 )
F = Factory D Burlington, Vt K Bromont, Quebec Q Shiga, Japan	A = Assembly Plant A Santa Clara, CA B South Portland, ME C South Portland, ME S Singapore
DD = Die Run Code	xx = Lot number
Y = Year 7 1997 8 1998 9 1999	Y = Year 8 1998 9 1999 0 2000
WW = Week	WW = Week
** = Lot Code (1 or 2 characters)	DD = Die Run Code (AB – ZZ)

RAW DATA – If You have a MediaGX or Geode please e-mail me the data as there may be more variations

What we learn from the data:
National began production using a 3.0 die mask.
National had transitioned all Geodes to die revision 5.x by November of 1999.
National had transitioned to die revision 8.x by May of 2000

B is a Beta die revision. Production dies started at A.
Japanese made MediaGX devices are rather uncommon