[geeks] sun ultra 24

[Lionel Peterson]

>From: nate at portents.com
>Date: 2007/10/17 Wed AM 11:05:05 CDT
>To: The Geeks List <geeks at sunhelp.org>
>Subject: Re: [geeks] sun ultra 24

>> Huh?
>>
>> FB and ECC are not in competition.
>
>Yes they are in competition in the server/workstation market, depending on
>the platform.  Multi-socket AMD means ECC *non* FB-DIMMs, multi-socket
>Intel means ECC FB-DIMMs.
>
>> My Mac has fully buffered ECC memory.
>
>Yes it does, because it is multi-socket Intel.  And FB-DIMMs currently
>consume a lot more power than non-FB ECC DDR2.
>
>8GB of non-FB DDR2 memory uses 36.94 watts under full load vs. 101.2 watts
>for 8GB of FB-DIMMs.  When idle, non-FB DDR2 memory uses 14.32 watts vs.
>83.34 watts for FB-DIMMs.
>
>This adds up quickly in data centers where you have lots of memory
>installed in lots of servers.
>
>FB-DIMMs do have some advantages (latency not being one of them, and their
>performance issues are largely masked by the massive on-chip L2 caches
>that Intel uses as well as a lot of extra work they put into their memory
>controllers).  FB-DIMMs can be set up to have failover modules so in a
>situation where a module goes bad in use, the motherboard can stop using
>it and switch to it's mirrored module (similar to RAID) without missing a
>beat.

What the heck??? Any pointers to info on such an arrangement (even if only in theory)? I don't see how it would work, as when the module fails, it will take a gig of data with it (how does the "hot spre" RAM module get populated once an error is detected?).

Oh wait, you mean you buy *double* the RAM you need to use, and run all memory operations in duplicate (on both DIMMs)? Ugh, that is one way to sell more RAM...

IMHO (and I am not in a production environment), memory is the one thing that almost ALWAYS works - what with it's lack of moving parts and such...

Lionel