dual channel and amd

bwanaaa

Senior member
Dec 26, 2002
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my question is whether the first dual channel pair are handled preferentially by the on-die mem controller than the second dual channel pair? Is there a preference or speed advantage to one pair?

This begs the question of why the timings are slower when all 4 slots are populated. any insight on this?
 

exar333

Diamond Member
Feb 7, 2004
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depends on the AMD core....if your talking A64, you must have a sandiego/venice/x2 core to "officially" support 4 dimms @ 400mhz....its just very stressfull on the memory controller to run dual channel x4 DIMMS...thats why it downclocked it on earlier cores...
 

bwanaaa

Senior member
Dec 26, 2002
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tnx for the reply. yea, i'm running an x2. just wondering what specifically about 4 slots creates stress-is the htt not high enough? and are the 2 dual channel pairs EXACTLY equal the way they are treated or is the second channel an overflow channel.?
 

Topweasel

Diamond Member
Oct 19, 2000
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You memory will run at the slowest sticks speed for starters. As for prefrential treatment the first pair has information written to it before the second so I guess that could be preferential treatment. The only stress is when four dimms at used on a .9 micron A64 (cept the winnie) you have to run it at 2T instead of 1T. So yes the second pair will by used as an overflow but again all sticks run at the worst sticks speed. Interms of second sticks think of each pair as a RAID 0 array, the information is split beyween the 2 to double bandwith.