Why Make K6-2s to Run @ 66MHz?

Addressing FAQ's on the AMD-K6-2/300/333 at 66-MHz bus

Why is AMD making the 300 and 333-Mhz processor available at 66-Mhz FSB?

AMD has produced the AMD-K6-2/300/333 running at the 66-Mhz bus to address the basic PC market. As the faster speed Super7™ processors such as the AMD-K6-2/350 become the mainstream, the 66-Mhz bus products are well positioned for the upgrade and entry-level market. The availability of these new products gives you an opportunity to address circumstances that are best handled with the older 66-MHz Socket 7 motherboards. As well, it gives upgrading users an opportunity to use their existing 66-Mhz EDO DRAM, and therefore offers overall system level cost savings.

For circumstances that require leading-edge technology and the high-end performance of the Super7 platform, it is recommended to use the AMD-K6-2/350 processor or faster.

What is the impact on performance when using the 66-Mhz bus as opposed to the 100-Mhz or 95-Mhz FSB?

While the performance of the AMD-K6-2/300/333 at 66-MHz will be a few percentage points lower than the standard AMD-K6-2 300/333 at the 100 or 95-MHz bus, much of the entry level market buys on clock speed and price, not purely benchmark performance. For most common business applications, this difference will not be very noticeable. However, if you are using the system for gaming or other applications requiring high performance, then it is highly recommended to use an AMD-K6-2 processor with the 100-MHz or 95-MHz FSB.

How can I tell the difference between the 100-Mhz FSB and 66-Mhz processors?

The unit will be marked as the following on the processor.

Part Processor Marking
300/100-Mhz FSB AMD-K6-2/300AFR
300/66-Mhz FSB AMD-K6-2/300AFR-66
333/95-Mhz FSB AMD-K6-2/333AFR
333/66-Mhz FSB AMD-K6-2/333AFR-66

Currently, the AMD-K6-2/300/333 processors at 66-Mhz FSB are not available in a boxed version, so any boxed 300/333-MHz parts will support the 100/95-Mhz bus speed. If future boxed product is intended for the 66-Mhz bus speed, it will be appropriately marked.

What motherboards support the AMD-K6-2/300/333 at the 66-Mhz bus?

All motherboards tested for AMD-K6 family should work with the 66 MHz parts as long as the bus jumpers are properly set for 66 MHz bus operation.

AMD, the AMD logo, K6, 3DNow! and combinations thereof and Super7 are trademarks, and AMD-K6 is a registered trademark of Advanced Micro Devices, Inc. All other product names are for identification purposes only and may be trademarks of their respective companies.