AMD's 760MPX Chipset - Multiprocessor for the Masses

Back in June we had some very strong words to say in favor of the first multiprocessor chipset from AMD. Indeed the 760MP had a lot of potential and performed quite well, but would it survive?

The platform did not gain any major OEM design wins although the HPs of the world were definitely paying attention to its progress. Instead, the 760MP was a hit among enthusiasts, early adopting risk-takers, and those that were well aware of the platform's power and potential. Thus it came as no surprise that just two months after we wrote about it, we were running it to serve our backend databases as well.

It will take time for the large OEMs to trust the AMD name to power their mission critical server solutions, but it starts with successes at the early adopter level in order to gain a reputation for the product. While there were no performance or stability issues with the 760MP when we first reviewed it, there were some limitations of the chipset design that would most definitely hold back its success as a true high-end product:

Support for only a single PCI bus - As trivial as it may seem to most desktop users, having only a single PCI bus is laughable when it comes to the truly high end server solutions. With a single powerful RAID array it is very easy to saturate a 32-bit/33MHz PCI bus leaving no room for network traffic among other things. Remember that the ServerWorks HEsl chipset for the Pentium III platform already supports two 64-bit/66MHz PCI buses and one 32-bit/33MHz bus.

Support for only a 64-bit/33MHz PCI bus - The original 760MPX only supported a 64-bit/33MHz PCI bus which is ok for most users but a lack of 66MHz PCI support is definitely a mark down for the 760MP. Going back to the previous example of the HEsl from ServerWorks, it had two 64-bit/66MHz PCI buses whereas this chipset didn't even have one.

Low-bandwidth North/South Bridge connection - Because it was only outfitted with a single 64-bit/33MHz PCI Bus, that same bus was used to connect the North and South bridges of the chipset. A 266MB/s link between the North and South bridges is fine for a desktop computer, but not for a server.

This completed the issues that most higher end server users would have with the chipset and it paved the way for the introduction of the true mass-production version of the chipset - the 760MPX.