Comments on: The difference is as plain as the ear on your face! http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/ the blog that is not dansdata.com Fri, 10 Feb 2012 17:48:09 +0000 http://wordpress.org/?v=1.5.1-alpha by: tammy83 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-7986 Thu, 22 Dec 2011 18:45:10 +0000 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-7986 Very good post with informative information. I really appreciate the fact that you approach these topics from a stand point of knowledge and information. This is the first time, I visited at your site and became your fan. You are bookmarked. Please keep on posting. <a href="http://dressestoweartoaweddinghq.com" rel="nofollow">Dresses to wear to a wedding</a> Very good post with informative information. I really appreciate the fact that you approach these topics from a stand point of knowledge and information. This is the first time, I visited at your site and became your fan. You are bookmarked. Please keep on posting.

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]]> by: tammy83 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-7985 Thu, 22 Dec 2011 18:43:59 +0000 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-7985 They may participate directly in collaborative artifact production and promotion (such as can be found within the machinima community, for example). Just as importantly, a person can devote much of their energies to regularly visiting a site central They may participate directly in collaborative artifact production and promotion (such as can be found within the machinima community, for example). Just as importantly, a person can devote much of their energies to regularly visiting a site central

]]> by: tammy83 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-7984 Thu, 22 Dec 2011 18:43:27 +0000 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-7984 From a long time I have been searching such Kind of things which should be good for me but I was not able to get even one of them but by searching and by passing by time lastly I got something to which I can trust and I can say that this one is the thing from which I can get a lot. now I came on the thing I like to thank to the blogger to give such kind of care to this cute blog and the commenters who gave us so many external knowledge From a long time I have been searching such Kind of things which should be good for me but I was not able to get even one of them but by searching and by passing by time lastly I got something to which I can trust and I can say that this one is the thing from which I can get a lot. now I came on the thing I like to thank to the blogger to give such kind of care to this cute blog and the commenters who gave us so many external knowledge

]]> by: Alex Whiteside http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5213 Tue, 07 Jul 2009 01:12:11 +0100 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5213 I'd still consider that "block access" a subset of random access. You can access addresses arbitrarily, with additional latencies appearing for traversing the heirarchy in certain ways. Maybe it's a side effect of coming in from the "sequential access" side and putting up with tape decks. It's probably not a taxonomically relevant distinction these days when every form of storage does random access in some fashion. My concern is that if you're going to say that "block access" isn't random access, then it's a slippery slope into saying that <i>nothing</i> is really random access. (I recall a CU Amiga article where the author found CD-ROM to be a huge misnomer, preferring CD-RAD (Random Access Disk). I'm not that bad, thankfully.) I'd still consider that "block access" a subset of random access. You can access addresses arbitrarily, with additional latencies appearing for traversing the heirarchy in certain ways. Maybe it's a side effect of coming in from the "sequential access" side and putting up with tape decks. It's probably not a taxonomically relevant distinction these days when every form of storage does random access in some fashion. My concern is that if you're going to say that "block access" isn't random access, then it's a slippery slope into saying that nothing is really random access.

(I recall a CU Amiga article where the author found CD-ROM to be a huge misnomer, preferring CD-RAD (Random Access Disk). I'm not that bad, thankfully.)

]]> by: Popup http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5212 Mon, 06 Jul 2009 23:57:04 +0100 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5212 &gt; Well, by definition, it's either got to be "random" or "sequential", Does it? I have heard (and used) the term 'block access' to mean the kind of devices where the latency is more-or-less independent of the size of the read request (up to the 'block size'). A prime example would be a hard disk, where the average latency is (as defined by the spin speed) on the order of 10ms, but the extra time required to read a single byte (as defined by transfer speed) is on the other of 30ns! > Well, by definition, it's either got to be "random" or "sequential",
Does it?

I have heard (and used) the term 'block access' to mean the kind of devices where the latency is more-or-less independent of the size of the read request (up to the 'block size').

A prime example would be a hard disk, where the average latency is (as defined by the spin speed) on the order of 10ms, but the extra time required to read a single byte (as defined by transfer speed) is on the other of 30ns!

]]> by: Alex Whiteside http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5211 Mon, 06 Jul 2009 23:37:26 +0100 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5211 Linear and additive, at that. Linear and additive, at that.

]]> by: Alex Whiteside http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5210 Mon, 06 Jul 2009 23:36:08 +0100 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5210 Well, by definition, it's either got to be "random" or "sequential", and it sure as hell isn't "sequential" access, as we had back in the old tape days, when the latency was linear with the distance between the memory locations. It's not completely address-independent random access, but nothing is. Even a perfectly crafted ROM will give you different (miniscule) latencies depending on where the address is physically stored on the silicon. Well, by definition, it's either got to be "random" or "sequential", and it sure as hell isn't "sequential" access, as we had back in the old tape days, when the latency was linear with the distance between the memory locations. It's not completely address-independent random access, but nothing is. Even a perfectly crafted ROM will give you different (miniscule) latencies depending on where the address is physically stored on the silicon.

]]> by: Popup http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5209 Mon, 06 Jul 2009 23:28:39 +0100 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5209 As a matter of fact, I wouldn't call a NAND flash memory 'random access', as the latency of a read is strongly dependent on previous reads. (For two reasons: - as the hardware will have to read an entire 4kb block at a time (to do error-checking/correction) odds are that sequential reads will already be available. - If the system is clever enough it will automatically pre-fetch the next block, and have it available in some kind of cache. In fact, you'll be hard-pressed to find true 'random access' anywhere, certainly not SDRAM, and in most application not even SRAM qualifies - even in those cases sequential accesses often lead to shorter latency, thanks to pre-fetching by the hardware, or caching at a higher level. In fact, the only 'random access' memory I can think of is 'ROM' i.e. good old-fashioned EPROM or the equivalent... As a matter of fact, I wouldn't call a NAND flash memory 'random access', as the latency of a read is strongly dependent on previous reads. (For two reasons:
- as the hardware will have to read an entire 4kb block at a time (to do error-checking/correction) odds are that sequential reads will already be available.
- If the system is clever enough it will automatically pre-fetch the next block, and have it available in some kind of cache.

In fact, you'll be hard-pressed to find true 'random access' anywhere, certainly not SDRAM, and in most application not even SRAM qualifies - even in those cases sequential accesses often lead to shorter latency, thanks to pre-fetching by the hardware, or caching at a higher level.

In fact, the only 'random access' memory I can think of is 'ROM' i.e. good old-fashioned EPROM or the equivalent...

]]> by: Popup http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5208 Mon, 06 Jul 2009 23:14:29 +0100 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5208 While I ought to know better than to pick a fight with someone who buys pixels by the barrel... Would you also call a hard disk RAM? While I ought to know better than to pick a fight with someone who buys pixels by the barrel...

Would you also call a hard disk RAM?

]]> by: Daniel Rutter http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5207 Mon, 06 Jul 2009 23:00:56 +0100 http://dansdata.blogsome.com/2009/07/06/the-difference-is-as-plain-as-the-ear-on-your-face/#comment-5207 I've never really thought about this in detail, but have instantly ginned up the following justification: Is flash memory a <a href="http://en.wikipedia.org/wiki/Sequential_access" rel="nofollow">sequential-access</a> device? Clearly not, except in a very restricted sense of the term. Is it therefore a <a href="http://en.wikipedia.org/wiki/Random_access" rel="nofollow">random-access</a> device, if we define that as storage which takes the same amount of time to access data anywhere on the device? Yes, it is. I don't think the block-erase limitation and resultant background controller trickery disqualifies it as a random-access device. So it's random-access, and it's memory, and thus it's RAM. (Of course, if someone made a reel-to-reel tape drive that worked at a billion miles an hour and could whip data under the heads as fast as a hard disk can, with no noticeable extra delay for accessing data on any part of the tape, then that might <i>also</i> qualify as RAM under this loose definition.) I've never really thought about this in detail, but have instantly ginned up the following justification:

Is flash memory a sequential-access device? Clearly not, except in a very restricted sense of the term. Is it therefore a random-access device, if we define that as storage which takes the same amount of time to access data anywhere on the device? Yes, it is.

I don't think the block-erase limitation and resultant background controller trickery disqualifies it as a random-access device. So it's random-access, and it's memory, and thus it's RAM.

(Of course, if someone made a reel-to-reel tape drive that worked at a billion miles an hour and could whip data under the heads as fast as a hard disk can, with no noticeable extra delay for accessing data on any part of the tape, then that might also qualify as RAM under this loose definition.)

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