G+_T. J. Sexton Posted August 7, 2013 Share Posted August 7, 2013 Just getting to listen to yesterday's episode. Gina Trapani fully redeems herself for last week's comparison of TRIM to defragging with a perfect metaphor for explaining RAM to non-techies. Will be shamelessly stealing it. Link to comment Share on other sites More sharing options...
G+_Joseph Cappellino Posted August 7, 2013 Share Posted August 7, 2013 That was a great analogy. My personal favorite is comparing it to a desk. What you're working on directly in front of you is like cache memory (located on the CPU) and is really quick to access the data, and extremely limited in space. Scattered on your desk is what is in your RAM, also really quick (but not as quick as cache). More storage, but it's not persistent. And the files in your drawers is like HDD/SDD data. Very long to retrieve data, but almost limitless in space and is persistent. This continues with when you need to work on something else, you need to put what you're working on back into RAM (the desk space). If there's no room in RAM, something from RAM goes into storage (the drawers). Then, you take what you need to work on out of RAM and into cache. Link to comment Share on other sites More sharing options...
G+_Greg Milner Posted August 7, 2013 Share Posted August 7, 2013 Here's the explanation in the show notes. https://docs.google.com/spreadsheet/pub?key=0AtdUwTOQMYundGRYSlViMHJoZXJtUkc0QXNOX0Rmenc&gid=56 "A closer chalkboard analogy for SSDs is a chalkboard that you have to erase completely in order to write to. Naturally, if there's something already there, you might want to maintain it, so you have to remember somehow what was there before you erase and then redraw it along with what you're adding or changing. That all happens in the SSD drive controller. What TRIM does is allow the OS (which knows what the file system looks like) to tell the drive controller (which doesn't) that a block of data in the SSD (which can be rather large... upwards of 512KB in some cases) is no longer needed, so the SSD controller doesn't need to read the block before it can erase and write it. That's where you get the performance increase. Brian Atlanta, GA" Link to comment Share on other sites More sharing options...
G+_Archit Jha Posted August 8, 2013 Share Posted August 8, 2013 The desk analogy above is what I always used to explain it to people! Link to comment Share on other sites More sharing options...
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