Don’t be me: buffered RAM

I was a bit giddy after after wholly successful laptop upgrade and decided to upgrade/max the RAM in my arch linux desktop, too.

Went on eBay and scored 16GB of used RAM for $25 to stuff in the old Dell Optiplex 740. I run some memory hungry applications on it:

  • virtualbox for running virtual machines.  I currently have an XP and a Win7 instance to spin up when needed.  Virtualization is also a good way to test linux distros.

  • Chrome/Chromium

  • calibre for ebook maintenance and conversion

  • various .pdf processing tools

The latter can actually use all the RAM and start swapping out, the only thing I’ve seen do that so far.

[Note:  Crucial gives the max as 8GB but anecdotes on the web suggest it will work with 16GB.  Apparently Crucial uses manufacturers’ specs for its listings.  But at the time 4GB sticks were not available so Dell did not test that configuration.  So if you have an old PC you might want to google the max rather than rely on Crucial (an otherwise excellent resource) for that info.]  The RAM came quickly and I stayed up (too) late to install it.  No boot.  Hmmm.  Tried different slots, stick order, etc.  Still no boot.  Grrrrr.

It turns out the RAM is fine and I messed up.  The listing clearly stated “server RAM” but I didn’t follow up on how that might be significant.  I ASSumed it meant it was pulled from a server.  Well, that was true but that wasn’t all it meant.

Turns out that server/ECC/buffered RAM is used in servers and high end workstations but is not compatitble with most desktops.  Oopsie.  $25 is a relatively cheap price to learn that lesson, and I might relist it for $10 or something to offset some of the loss.

I went back on eBay and bought the non-ECC type for the linux box.  I’ll let you know how that turns out.

I’ll quote the seller’s info on ECC RAM here for the benefit of others:

The memory types **"F"**, **"R"**, and **"P" **are **NOT COMPATIBLE WITH MOST DESKTOP MOTHERBOARDS. **Most desktop motherboards are only compatible with unbuffered memory. **"E"** is compatible but the ECC function will be bypassed. **How do you identify the memory type? **The label for the memory type specifies the features. It's designated by the last letter(if there is one). For example, in the label **"PC2-5300F"** the last character** "F"** designates the memory as fully buffered. Additionally, **"R" **and **"P"** designates the memory as registered, **"E"** designates the memory as ECC unbuffered, and **"U"** designates it as unbuffered. The lack of a letter designates it as unbuffered.