Talk:Single instruction, multiple data

message: Other examples of early SIMD machines were: 
* Xplor supercomputer, from Pyxsys, Inc., circa 2001
* Connection Machine, models 1 and 2 (CM-1 and CM-2), from Thinking Machines Corporation, circa 1985
* Zephyr DTC computer from Wavetracer, circa 1991
* Massively Parallel Processor (MPP), from NASA/Goddard Space Flight Center, circa 1983-1991
There were many others from this era as well. At least some of them deserve mention on the SIMD page.  — Preceding unsigned comment added by Gwilcox (talk • contribs) 20:35, 13 February 2005 (UTC)
thread_title: Other early SIMD machines

message: Max. Popularity :
* SIMD is very used for these slowest video-codecs of complex design : XviD, DivX, H.263+ AVC (the best of 2004 was AVC NeroDigital), ...
The reasons are that many users are P2P users, movies pirates, porn viewers, ...
and they need to compress the space of
MPEG-2 DVD 4.7 GB to XviD/DivX/AVC MPEG-4 CD 700 MB (for slow Internet)
using the tool VirtualDub.
The typical time to complete the compression with SIMD depending on the used codec
is between 2 hours using the fastest PC and 12 hours using the slowest PC.  — Preceding unsigned comment added by 62.14.140.198 (talk • contribs) 15:45, 15 March 2005 (UTC)
thread_title: Max. popularity

message: Another SIMD/MIMD architecture has emerged in stream processors. I am not well aware of where to put this update in the page (maybe a previous editor has an idea). I believe it's quite important this page (the only which is not a stub) also mentions the new paradigm functionality.
MaxDZ8 09:52, 27 October 2005 (UTC)
thread_title:  Stream processing 

message: *$1 = $2 + $3
**Single instruction ? Yes: +
**Multiple data ? Yes: $1, $2, $3
There's no definition of what SIMD means. Please write one in the text. --Hdante 11:25, 4 March 2006 (UTC)
thread_title:  SIMD definition 

message: there is a bad link in http://www.teranex.com/support/docs/TeranexParallelProc.pdf  — Preceding unsigned comment added by  Pizzadeliveryboy (talk • contribs) 12:11, 2 June 2006 (UTC)
thread_title:  bad link 

message: Shouldn't it be 300%?  — Preceding unsigned comment added by Berniefu (talk • contribs) 00:52, 10 December 2012 (UTC)
thread_title:  Why the speedup is 75% in the graph? 

message: In the Hardware section is sais: "Intel's AVX SIMD instructions now process 256 bits of data at once", isn't it deprecated, and now in 512 bits?  — Preceding unsigned comment added by Themarina.m (talk • contribs) 14:44, 13 August 2017 (UTC)
thread_title:  YMM vs ZMM 

message: In the Software section the Microsoft.Bcl.Simd library is linked, but it has been deprecated in favour of the System.Numerics.Vectors NuGet package. Frabert (talk) 09:44, 12 January 2018 (UTC)
thread_title:  .NET SIMD linked library has been deprecated 

message: Thus, such machines exploit data level parallelism, but not concurrency: there are simultaneous (parallel) computations, but only a single process (instruction) at a given moment.
Why do we have this automatic boner for parallelism? (In my experience, "exploit" is almost always parallelism's preceding verb; bonerville by any other name would smell as sweet.) 
What we really need to be saying is that in cases where regimentation is natural (or can be imposed upon the data), SIMD allow fewer instructions to process more data—this being important if performance (in either the time or energy domain or both) is architecturally rate limiting. 
There's another meaning of parallelism where you try to avoid creating false dependencies: every operation with its arguments available is free to dispatch. In this regime you don't end up at low resource utilization waiting for a slow boat. That's the notion of parallelism which is closer to the bonerific free lunch. But that glorious notion of parallelism has nothing to do with SIMD at all. It just happens that modest SIMD (registers in the 256-bit range) is compatible with superscalar OOO. 
I know I'm not in the majority here, but parallelism is not an elementary explanatory term if you make any effort to think clearly. 
The actual trade-off here is that in cases where you can sufficiently regiment the data (which might be painful for the programmers or other computational units within the system), you decrease the instruction dispatch rate per volume of data processed. 
Note also that we didn't originally classify fetching AX and then processing the two halves separately as AH and AL as a SIMD fetch operation. Chunking optimizations are also a slightly different concept. You can also feed arithmetic units in parallel with superscalar dispatch (macro-op fusion could also take you there on the internal execution path, even if it's not explicit in the ISA). Chunking is inherent in almost all modern cache design. 
The really core idea of SIMD is explicit data regimentation, and the driving motivation for this is to conserve orchestration resources at some level, because orchestration has fundamental costs and limits. — MaxEnt 22:07, 26 April 2018 (UTC)
thread_title:  Leaning on parallelism without much thought 

message: The two diagrams in the article for some reason use a "tengwar" font, which makes no sense for an article on cpu instruction handling. Can anyone generate new diagrams that use normal fonts instead of using Lord of the Rings typography? Pomax (talk) 06:11, 28 December 2018 (UTC)
thread_title:  Replace diagrams to ones that don't use an Elvish font 

message: In conjunction with MaxDZ8's comment regarding stream processing, it seems this page should mention Groq as a provider of SIMD/stream processing solutions Groq Technology. Perhaps in the "Commercial applications" section? Cl.taurus (talk) 18:08, 23 April 2021 (UTC)
thread_title:  Mention Groq in Commercial applications section? 

message: :The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion. 
The result of the move request was: Moved, with the redirect from the acronym remaining in this instance. (And apologies for the mix up with the SISD move earlier, that is now fixed).   — Amakuru (talk) 16:26, 28 January 2022 (UTC)
replies: text: SIMD →  – Propose to move the article title to the full name as it immediately becomes more descriptive and easily recognizable for users somewhat familiar with computer architecture, by recognizing the words "instruction" and "data". However, this may however conflict with WP:TITLEFORMAT. The same change has been proposed for SISD, SIMD, MISD, MIMD). Sauer202 (talk) 13:24, 21 January 2022 (UTC)
thread_title:  Requested move 21 January 2022