Motherboard for National Geode GX1 - 300P

[feipoa]

I recently acquired a National Semiconductor Geode GX1 - 300P CPU in the PGA form factor (attached image).The Geode 300/333 MHz GX1 CPU is not easily found in the PGA form factor. The chip is [almost] a Cyrix Media GXm CPU, aka Geode from National Semiconductor. According to Wiki, it is nearly identical to the original Cyrix Media GXm CPUs, but with a die shrink, that is, .18 um instead of .35 um.

I have the 266 MHz Media GXm CPU in a system now, but would like to maximise the speed to 300 MHz. I was hoping that this GX1 will would in the GXm motherboard. Wiki mentions that the GX1 uses the CS5530A companion chipset, while the GXm uses the CS5530 chipset. I am hoping that the "A" suffix is only related to which onboard graphics and sound is used on the CPU. On my system I have the integrated sound and graphics disabled, so was thinking that this 300 MHz GX1 chip would work. This chip is the fastest Cyrix 5x86-based CPU in my collection. The purple lettering is also pretty neat.

I tested the chip in an ECS P5GX-M, which is possibly the best socket 7 MediaGX board. I left the multiplier set for 266 MHz and set the voltage to 2.1 V. The system POSTed and began to boot, but, both, Win9x and NT4 would not boot properly. NT4 actually rebooted on its own without signaling an error, not even a BSOD, while Win98SE spat out some error and stopped at the DOS prompt. Unfortunately, it seems like the NS5330A chipset required by the GX1 is different enough from the NS5330 that the GX1 chip will not work on this motherboard. For completeness, I also set the jumpers up for 300 and 333 MHz, but the screen stayed all black after power-up.

I think it would be pretty neat to get this CPU up and running, so my question is, what motherboard model will this CPU run in? Has anyone seen a GX2? I assume the GX2 would be the last CPU based on the Cyrix 5x86 core. Thanks!

[Guest]

I was thinking about purchasing one of these boards and would like to know if anyone knows the answer?

[CPUShack]

Did you try running it slower? say at 200?

[nliwilson]

I’ve also just bought this board & would like to know if I can use a GX1 with it, if anyone knows please?

[feipoa]