AMD and northbridges

[diegophil]

I have been out of the hardward area for sometime. Being as such, it surprised me recently when reading a review on the A8N32-SLI boards. What hit me first was the presence of a northbridge heatsink. It took me a minute to figure out what I was seeing, but after reading the article, it stated it was indeed a heatsink for the northbridge. So, I did some googling and some seraching to find out it is a C51 northbrdige w/o integrated graphics and that the northbridge controlls 16x lanes for teh graphics and the southbridge does the same plus some. I write this post mostly to make sure I understand what is going on with the new northbridge and to ask is this all the northbrdige does, or am I missing something else?

Thanks in advance for your responses. I like to know what is going on with the newest [H]ardware, even if I cant buy it.

 

[rufflove]

The A8N boards don't have a Northbridge as such - it does indeed sound like you need to do some catching up! The nForce4 boards use a single chip solution, known as an "MCP" in nVidia jargon.

Check out the nForce 4 tech data: http://www.nvidia.com/page/nforce4.html

In particular, look at this: http://www.nvidia.com/object/IO_8453.html

 

[diegophil]

Thank you for posting, Please look at an A8N32, not the A8N boards. There is indeed a second chipset just under thecpu socket, then there is the southbridge.

 

[diegophil]

bump

 

[Dan_D]

The Northbridge indeed is present. On the A8N32-SLI Deluxe and with any NForce 4 SLi x16 based board, or the NForce Professional 2200/2050, the Northbridge has all the duties of a traditional two chip solutions southbridge. It is what provides PCI/PCI-E support. It provides your USB ports and I/O for SATA/RAID and other things. Networking is also built into the Northbridge.

The second chip in the NForce 4 SLI x16/NForce Professional Solution is there for the sole purpose of adding additional PCI-Express lanes for the second PCI-E slot and any needed above that for additional PCI-E slots not covered by the number of lanes provided by the Northbridge.

 

[diegophil]

thanks for the response. I am a little confused as to which one your speaking about, but I think the first one your talking about is the south bridge and the later paragraph is the "north bridge". Correct me if I am mistaken.

 

[mavalpha]

The original nForce4 was a single-chip solution; that is, it incorporated traditional North- and South-bridge functions into one chip, which nVidia calls the MCP. What you term the Northbridge, is actually a middle-man that is specific to SLI x16; its sole purpose is to add eighteen PCIe lanes to the nForce4 chipset as a whole. The piece that you consider the southbridge is a full-blown nForce4 SLI chipset, that's been tacked onto the end of a sort of daisychain stemming from the processor and extending through the additional x16 hub.

 

[Dan_D]

The Northbridge, as in the one closest to the CPU actually has all the systems on board functions. The Southbridge, just adds the PCI-Express lanes.

This is the way it is done on the NForce Professional 2200/2050 chips.

The "Northbridge" is the closest to the CPU and has most of the functionality. The same as with standard NForce 4's. The second chip closer to the IDE ports and SATA ports is the Southbridge. Adding only PCI-E lanes. The NForce 4 SLI x16 chipset is virtually identical to the NForce Professional combination of chips as near as I can tell. Minus anything that might be needed for the Opterons extra HTT links or memory support.

Most of the added support needed for the Opteron is provided by the AMD 8131 PCI-X tunnel chip I suspect.