Talk:Single instruction, multiple threads

Latest comment: 21 days ago by Lkcl in topic Same as SPMD

Does 'SIMT' Include Latency-Hiding?

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Should we consider 'SIMT' to include the latency-hiding strategy used by its current-day implementations, whereby different warps can be switched between with zero overhead?

One could construct a SIMT architecture which did not have this scheduling strategy, after all (as, say, an extension to an ordinary CPU architecture), but this scheduling strategy is central to the way SIMT is used today.

For now, I've assumed it is to be included in 'SIMT', and have made this change accordingly: 28 August 2014‎.

Wootery (talk) 17:16, 28 August 2014 (UTC)Reply

Did NVidia Invent SIMT?

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In their processor just before the ZMS-05, 3DLabs (now ZiiLabs) used SIMT, which (to me) is just SIMD with some paths disabled some of the time, and converting to a jump if they are all disabled. Who was first to use SIMT? — Preceding unsigned comment added by Nickpelling (talkcontribs) 10:21, 18 November 2018 (UTC)Reply

yyeah i don't really know, it's a very good question. with all the history of computing that dates all the way back to the 50s, i doubt very much that nvidia invented SIMT. but you do have to be very careful about architectures. SIMD is most emphatically *not* SIMT, even when you have predication (which it looks like you're saying that the SMS-05 was designed with?). i will keep looking :) Lkcl (talk) 15:39, 14 April 2025 (UTC)Reply

Same as SPMD

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I think this article should either be merged with SPMD, or it should be explained how the two are different. Here's a lecture by a senior computer architect saying that they are synonyms: youtube_com/watch?v=mgtlbEqn2dA&t=808 — Preceding unsigned comment added by 180.150.36.7 (talk) 03:47, 5 October 2019 (UTC)Reply

ah. right. no, but you raise a really good "differentiator" :) "in SPMD parallel execution, multiple autonomous processors simultaneously execute the same program at independent points," - that is NOT the same as SIMT. SIMT is definitely the instruction being BROADCAST (all processors execute the SAME instruction, because there is only one Program Counter), where SPMD it is very clear that there are MULTIPLE program counters. superb that you brought this up, i'll just do an edit now Lkcl (talk) Lkcl (talk) 15:42, 14 April 2025 (UTC)Reply