32GB RAM supported if slower Ram, 16GB if faster ( why? )

[DaveLembke]

http://ark.intel.com/products/27743/Intel-E7520-Memory-Controller

Working on the server again tonight at work that is referenced in another post. I decided to look into to memory controller to see what RAM is supported.

What is very strange is that this memory controller states that it supports 32GB of RAM if its 266Mhz, yet 333Mhz and 400Mhz DDR RAM is limited to 16GB.

Anyone know why the limitation based on speed? Never seen anything like this before, as for its usually a max RAM count across the board no matter FSB speed.

* I'm only running 4 x 512MB sticks at 2GB so nowheres near the limit for any speed, but found this interesting.

[giardmi09]

Interesting, maybe the speed drop is due to bandwidth limitations?

Not sure but that's all I got.

[patio]

All i know is there have been volumes written on how picky Xeon servers are about RAM and it's configurations...Intel has a bunch of info on it.

[DaveLembke]

Never knew that Xeon servers were picky when it comes to RAM. Will dig further on this subject on one of my breaks. Also bandwidth limitation might be a good educated guess. Just surprised that the limitation doesnt follow a linear fit in which 266Mhz = 32GB Max, 333Mhz = 24GB Max, and 400Mhz = 16GB Max, but maybe it did support 24GB at 333Mhz but was unstable for some reason and thats why they kept the 333Mhz RAM at 16GB just like the 400Mhz RAM.

Thanks for input on this