Why doesn't this DDR2 RAM fit into this supposedly DDR2-compatible Supermicro motherboard?

antblazer

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Feb 6, 2014
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Hello,

I was slightly embarrassed this past week when I ordered this ram to upgrade this motherboard for a lab server. The RAM only slightly didn't fit (maybe one tooth off), but I was perplexed because I had run this through several compatibility filters and this seemed like the right pick.

When I took the original RAM out, it looked like this, and had the description "DDR2 pc5300." I thought DDR2 and PC2 are synonymous? How can RAM be both DDR2 and PC?

In any case, I can't seem to find this particular RAM anywhere, and I'm not sure what to look for.

I found the information through the 'lshw' command in Ubuntu. Is there a chance that this is wrong? Or am I missing something obvious about the RAM I ordered?

Thanks for any information!

 
Solution
The HP sticks you linked to are "Fully Buffered." This is from wikipedia: "240 pin FB-DIMM DDR2 are notched differently from conventional 240-pin DDR2. Those types are neither mechanically nor electrically compatible." (http://en.wikipedia.org/wiki/Fully_Buffered_DIMM)

Just get any DDR2 pair that isn't fully buffered and you should be fine.

mgolus

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Apr 25, 2012
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The HP sticks you linked to are "Fully Buffered." This is from wikipedia: "240 pin FB-DIMM DDR2 are notched differently from conventional 240-pin DDR2. Those types are neither mechanically nor electrically compatible." (http://en.wikipedia.org/wiki/Fully_Buffered_DIMM)

Just get any DDR2 pair that isn't fully buffered and you should be fine.
 
Solution

antblazer

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That's it. On the wiki I can see the difference in notches, which matches the difference in my case. Thanks!
 

antblazer

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You think this will be OK?