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Questions:

1. Is dual-channel operation so sensitive that one should only run it
with memory bought as pairs?

2. Does dual-channel operation enhance performance enough to be worth it?

Discussion:

In the thread I started on how to determine in-system RAM
specifications, Joseph pointed out:

"Unpaired DIMM's will still work, the dual-channel interleave just
won't. You may have to set your BIOS to not use dual-channel to make it
work properly.

The bigger issue is that, even from the same manufacturer, if the specs
on 2 banks are slightly off (this often shows up in the non-speced
timings), the MB may run fine in dual-channel mode, except for
occasional errors that won't be noticed without ECC enabled, and may
lead to random system instability.  That's why it's generally best to
buy paired DIMM's if you want to run dual-channel RAM. If you aren't
doing that, then just make sure dual-channel is turned off, run DIMM's
with the same specs for flexibility, and don't worry about manufacturer
so much."

That sounds like proper dual-channel mode operation is a pretty
sensitive thing.  It also sounds like one could buy a RAM module today
and another of the same part number and manufacturer 6 months from now.
 And the second module would most certainly be of a different lot or
production run which could cause the problem Joseph describes.

So, I see a few options for me in my situation and would like feedback
from those with more experience with RAM concerns than I.

1 - Buy a proper speed and size module from where ever, disable
dual-channel and be happy with double the RAM space.  This is the safe
and least expensive route but no dual-channel.

2 - Buy a proper speed and size module from where ever, run dual-channel
and risk the sensitivity.  This is risky based on Joseph's description.
 Silent data corruption is very bad!

3 - Buy a proper speed and size module from Toshiba (my computer
manufacturer) and more expensive than third party RAM, run dual-channel
and still risk the sensitivity.  This is the safest for dual-channel
without buying double the RAM.

4 - Buy a new RAM pair from where ever, remove the RAM I already have,
run dual-channel with the new pair and less worry about sensitivity.
Sell the original module on eBay.  This is the solution for confident
dual-channel but is considerably more expensive.  (And problematic since
I could not see the current RAM module on my first look into the case.)

Maybe I am making a mountain out of a molehill here.  If dual-channel
performance does not make that much difference, it doesn't really matter
and I'll just take option #1.

Alan


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