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> The reason is that in these domains (e.g. game consoles, supercomputing), you know ahead of time the precise hardware characteristics of your target, you can

> The reason is that in these domains (e.g. game consoles, supercomputing), you know ahead of time the precise hardware characteristics of your target, you can assume it won't change, and can thus optimize specifically for that ahead of time. Cell was a failure in large part because this proved to be less true / less relevant than its designers thought. Source: many late nights / weekends trying to get PS3 launch titles performing well enough to ship.

scott_s 9y ago
I did work in graduate school trying to make the Cell easier to program - basically, providing OpenMP-like abstractions that would take advantage of the SPEs. I've always been really curious: how much did your games take advantage of the SPEs? When did you send code to the SPEs versus using the GPU? Were you using libraries that helped managing the SPEs, or did you do all of it manually?
- mattnewport 9y ago
  OpenMP is a bad approach for the types of problems commonly encountered in games and graphics programming in my experience. Matt Pharr's excellent series of articles on the history of ISPC gives some good explanations of what programming models actually work well for graphics particularly: http://pharr.org/matt/blog/2018/04/30/ispc-all.html http://pharr.org/matt/blog/2018/04/30/ispc-all.html At the time I was doing most of my SPE work (helping to optimize launch titles at EA prior to the launch of the PS3) most titles weren't taking much advantage of them at all. We were a central team helping move some code that seemed like it would most benefit over, I was particularly involved in moving animation code to the SPEs. There weren't really any options for libraries to help at that point, other than things we were building internally, so it was almost all manual work. Later on in the PS3 lifecycle people moved more and more code to the SPEs. To my knowledge most of that work was largely manual still. For a while I was project lead on EA's internal job/task management library which had had a big focus on supporting use of the SPEs but my involvement in it was mostly during the early part of the Xbox One / PS4 generation. The Frostbite graphics team in particular did a lot of interesting work shifting GPU work over to the SPEs (I think some of it they've talked about publicly) but I wasn't directly involved in that.
  - scott_s 9y ago
    I completely believe you on OpenMP being bad for games and graphics programming; we were targeting the HPC community which had a heavy interest in Cell as well. But all the while, I knew a bunch of programmers out in the world were shipping Cell code, and I was always curious what their patterns were. Thanks for the answers!

scott_s 9y ago

I did work in graduate school trying to make the Cell easier to program - basically, providing OpenMP-like abstractions that would take advantage of the SPEs. I've always been really curious: how much did your games take advantage of the SPEs? When did you send code to the SPEs versus using the GPU? Were you using libraries that helped managing the SPEs, or did you do all of it manually?

mattnewport 9y ago
OpenMP is a bad approach for the types of problems commonly encountered in games and graphics programming in my experience. Matt Pharr's excellent series of articles on the history of ISPC gives some good explanations of what programming models actually work well for graphics particularly: http://pharr.org/matt/blog/2018/04/30/ispc-all.html http://pharr.org/matt/blog/2018/04/30/ispc-all.html At the time I was doing most of my SPE work (helping to optimize launch titles at EA prior to the launch of the PS3) most titles weren't taking much advantage of them at all. We were a central team helping move some code that seemed like it would most benefit over, I was particularly involved in moving animation code to the SPEs. There weren't really any options for libraries to help at that point, other than things we were building internally, so it was almost all manual work. Later on in the PS3 lifecycle people moved more and more code to the SPEs. To my knowledge most of that work was largely manual still. For a while I was project lead on EA's internal job/task management library which had had a big focus on supporting use of the SPEs but my involvement in it was mostly during the early part of the Xbox One / PS4 generation. The Frostbite graphics team in particular did a lot of interesting work shifting GPU work over to the SPEs (I think some of it they've talked about publicly) but I wasn't directly involved in that.
- scott_s 9y ago
  I completely believe you on OpenMP being bad for games and graphics programming; we were targeting the HPC community which had a heavy interest in Cell as well. But all the while, I knew a bunch of programmers out in the world were shipping Cell code, and I was always curious what their patterns were. Thanks for the answers!