The Alpha EV6 Bus

One of the biggest differences the AMD K7 will implement over existing "x86" processors is the use of the Alpha EV6 bus. This will differ from the GTL+ used by the Intel P6 family in a number of VERY significant ways.

The EV6 bus unlike the GTL+ operates only between the CPU and the chipset. This allows a very high speed data pipe to be established between the processor and core logic. The EV6 DOES NOT talk directly to the memory, but instead leaves this up to the chipset. The upshot of this is that a 200 MHz bus can be run with PC 100 SDRAM as the memory bus is independent from the processor bus. The K7 will also see separate buses for AGP and and PCI.

This means that the K7 can be run with a wide variety memory types including:

• PC 100 SDRAM. The current high volume manufactured memory.
• RDRAM aka RAMBUS, can run up to speeds of 800 MHz, but is currently very costly to manufacture.
• DDR SDRAM meaning Double Rate SDRAM. Can achieve RDRAM levels of performance at 100 MHz. Works in way similar to AGP 2X.

This EV6 bus will be especially useful for high end server and workstation machines as it implements "point to point" topology allowing CPU's to establish an independent link to the chipset. This of course is only of use in multi-processor systems but is a huge advantage over GTL+ in that each chip has its own connection to the chipset, whereas under GTL+ each processor must share one single connection. This allows up to 16 K7's to be run in a multi-processor system!

Chipsets for the K7 will come initially from AMD itself, with companies such as VIA Technologies and Acer Labs Inc (ALi) following later.

Floating Points

Initial reports also point to a very impressive floating point math performance from the K7. The K7 feature 3 independent pipes for FPU instructions which operate in parallel. Aces Hardware estimates that the K7 could have up to 40% faster FPU performance than current Pentium III processors! This would be a significant performance boost!

This does look very impressive indeed. What though are Intel up to allowing AMD to get so far ahead? Well, once again, read on...

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Other AMD Processors at:

• AMD K5 page
• AMD K6 page
• AMD K6-2 page
• AMD K6-3 page