Memory Lane

Yes, it 's true that the Pentium has a 64-bit I/O interface to main memory. The same goes for all fifth- and sixth-generation x86 processors.

Here's why it would be useful for Cyrix to make the 6x86 run at higher clock speeds: At 150 MHz, the 6x86 closely matches the performance of Intel's 200-MHz Pentium, but it can't match the performance of the 200-MHz Pentium Pro. If Cyrix chips could achieve higher clock speeds, they could compete directly with Intel's latest CPUs instead of Intel's last-generation CPUs. As I pointed out in my story, the 6x86's lack of MMX is not the main question -- it's whether Cyrix can successfully design a CPU that's fully compatible with MMX. If Cyrix doesn't have access to the same intellectual property that Intel and AMD do, it will be more difficult for the company to devise a compatible solution. -- Tom R. Halfhill, senior editor