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Memory - more than you wanted to know!

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a b } Memory
a c 177 V Motherboard
May 16, 2010 11:07:05 PM

Since the advent, and common use of DDR3 memory, with its huge variety of available frequencies and latencies, memory selection and use has become an on-going nightmare for many. One thing repetitive questions have made apparent is that the more you've paid for your RAM - the le$$ likely you are to be able to get it to work acceptably! This is unfortunate - and unnecessary! I have thought, for some time (pretty much since the first i7 problems started cropping up), to try to put together a comprehensive guide to making an informed decision about buying RAM - and then, being able to actually get it working!! :sol: 

I know people these days, on average, are to some degree 'math-phobic', so I will keep the formulae and calculations to a minimum - but - I will work out some 'examples', and will provide an evaluation tool to 'get the math done', as it's the only way to actually know anything about prospective purchases!

This article has been 'subdivided' into four sections, mainly to compensate for the limitation on 'graphic citations' per post... (I need all the illustrations I can get!) :kaola: 

Part I - "What memory is"
Part II - "What memory does"
Part III - "Evaluation and selection"
Part IV - "Tweaking and tuning"

Section one is generic to all memory; the basic concepts apply to both DDR2 and DDR3, used with pretty much any processor. The examples in section two are mostly from Intel 1156/1366 platforms, but are also pretty 'generic'; I've joked numerous times about how little I know about AMDs, simply due to the comparative paucity of documentation:

"Funny, I've heard that bilbat guy only knows a lot of arcane BS about Intel processors - cause they're the only ones who document everything! If you wanna know how many Lahore pigeons crap on the roof of the Santa Clara fab each year, not only can you find it in a PDF somewhere (but where - that's the skill!) on their web site, but there's probably a three year plan documented to change their feeding habits, so they crap a lighter color, causing the roof to reflect more sunlight, and cut down on the air-conditioning costs... Every time I try to find out something about an AMD BIOS for someone, I see this business about "update AGESA three point five point three point nine point more digits than pi", and I've been randomly trying for months just to find out what 'AGESA' is - bah - no luck! (I hate acronymns anyway - the only one that ever sticks in my head is back from the days when they finally got completely out of hand with 'PCMCIA' - people can't memorize computer industry acronymns!) And you don't wanna even get me started about nVidia! As far as I can figure, nVidia is actually a front company for the CIA/NSA - if you go looking there for documentation, they'll have you investigated to find out why the hell you're looking for their documents!"

Since I posted that, not only have I learned what 'AGESA' is ("AMD Generic Encapsulated Software Architecture" - there's a mouthful for 'ya!), but (be still my beating heart), AMD've actually released 'pseudo-coded' sample programming!

Anyway - enough levity![:jaydeejohn:4]

Section three, evaluation, again references the Intel 1156/1366 platforms, but the actual explanations, as well as the 'eval tool', can be used for any DDR3-based system... This was originally titled "GIGABYTES and Memory", as I mostly post there, and I've selected their products to concentrate on, so the actual techniques discussed in the 'tweaking and tuning' section refer to GB boards and BIOS; it was converted to a 'general memory' reference at the suggestion of 'the management'! However, once again, the concepts of clocks, multipliers, and processor 'subsections' are generic, and the actual settings pretty much have to exist on any manufacturer's 'overclockable' MOBO - just the names are likely different, and their functional 'cross-referencing' will have to be surmised by the user...

I want to 'borrow' from my buddy and mentor over at TweakTown, LSDmeASAP, a few 'caveats':
  • I don't know everything...
  • I make misteaks all the time...
  • Sometimes my spelling is atrocious...
    and I'll add another of my own:
  • I'm a 'wordy' b@st@rd - I meander, I blather, and sometimes I rant & rave![:henry chinaski:1]

    If you don't care to read this much, or know this much, I've tried to put 'bullet-point' summaries at the ends of technical sections; you could 'skim through', look at the summaries, and then 'jump back' to examine the details of anything you'd like 'expanded upon'...
  • More about : memory wanted

    a b } Memory
    a c 177 V Motherboard
    May 22, 2010 11:16:22 PM

    ...scuzeamee - 'bumped' for ease of editing!
    a b } Memory
    a c 177 V Motherboard
    May 23, 2010 2:51:33 PM

    ...and again...
    !