Some 'reverse-engineering' of Zen

By: juanrga (nospam.delete@this.juanrga.com), October 30, 2015 12:00 pm
Room: Moderated Discussions
lurker (lurker9000.delete@this.realemail.mail) on October 30, 2015 5:56 am wrote:
> dmcq (dmcq.delete@this.fano.co.uk) on October 30, 2015 5:12 am wrote:
> > I think 256 bits would be better as you can do four double precision operations at once and that is quite
> > common. On the other hand with four SIMD units instead one could merge two operations to give an effective
> > two by 256 bit units except for some special operations.
>
> 256 bits would be ideal, but I don't think 128 bits is going to be terrible for general
> applications. A lot of software don't even use AVX instructions. And as you said the
> four pipes can merge to execute 256 bit ops so at least that's something.
>
> > For anything larger they'd probably be better
> > off relying on GPUs I think if they can get the coherence and message passing working well. I can see
> > how to save larger register sets without impacting interrupt handling too badly but it seems a lot of
> > work when ARM is probably hoping to move 64 bit ARM into the embedded processor market.
>
> That reminds me, isn't AMD working on an HPC APU? Perhaps they decided that more intense workloads
> will be offloaded to the GPU anyway so they didn't bother that much with beefier FPU?

There are difficulties with offloading computations. Moreover, some time ago engineers shared the next concept APU for HPC



with two 256-bit FMA units could be fused into a 512-bit unit.

The fact AMD Zen provides 256-bit AVX compatibility via fusing 2x 128bit units shows that they consider 256-bit software is relevant enough to be supported.

The real reason why AMD Zen is stuck with 128bit units can be cache/memory bottlenecks or Skybridge (pin and inside compatibility of both K12 and Zen) or simply saving die space or .
< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
Some 'reverse-engineering' of Zenjuanrga2015/10/03 03:48 AM
  Some 'reverse-engineering' of ZenHeikki Kultala2015/10/03 07:01 AM
    Some 'reverse-engineering' of Zenitsmydamnation2015/10/03 02:47 PM
      Some 'reverse-engineering' of ZenAnders2015/10/03 10:04 PM
        Some 'reverse-engineering' of ZenContrarian2015/10/04 10:53 AM
          Some 'reverse-engineering' of ZenJukka Larja2015/10/05 08:15 AM
            Some 'reverse-engineering' of Zenmpx2015/10/05 08:37 AM
              Some 'reverse-engineering' of ZenContrarian2015/10/25 11:25 AM
                Some 'reverse-engineering' of Zenitsmydamnation2015/10/26 12:49 AM
                Some 'reverse-engineering' of Zenjuanrga2015/10/29 01:16 AM
                  Some 'reverse-engineering' of Zenanon2015/10/30 05:54 AM
                    Some 'reverse-engineering' of Zenjuanrga2015/10/30 09:37 AM
                    POWER8 load/store unitsGabriele Svelto2015/10/30 05:34 PM
                Some 'reverse-engineering' of Zenlurker2015/10/29 02:12 PM
                  Some 'reverse-engineering' of ZenDavid Kanter2015/10/29 11:06 PM
                    Some 'reverse-engineering' of Zenlurker2015/10/30 01:39 AM
                      Some 'reverse-engineering' of ZenGabriele Svelto2015/10/30 02:14 AM
                        Some 'reverse-engineering' of Zenlurker2015/10/30 02:41 AM
                      Some 'reverse-engineering' of Zendmcq2015/10/30 04:12 AM
                        Some 'reverse-engineering' of Zenlurker2015/10/30 04:56 AM
                          Some 'reverse-engineering' of Zendmcq2015/10/30 05:09 AM
                            Some 'reverse-engineering' of Zennone2015/10/30 05:16 AM
                          Some 'reverse-engineering' of ZenDavid Kanter2015/10/30 07:16 AM
                            Some 'reverse-engineering' of Zenlurker2015/10/30 07:44 AM
                          Some 'reverse-engineering' of Zenjuanrga2015/10/30 12:00 PM
                            AVX and 128-bit FPUs in Zen(Re:Some 'reverse-engineering' of Zen)Heikki Kultala2015/10/30 02:45 PM
                              AVX and 128-bit FPUs in Zen(Re:Some 'reverse-engineering' of Zen)juanrga2015/10/31 05:20 AM
                                AVX and 128-bit FPUs in Zen(Re:Some 'reverse-engineering' of Zen)Heikki Kultala2015/10/31 01:19 PM
                                  AVX and 128-bit FPUs in Zen(Re:Some 'reverse-engineering' of Zen)juanrga2015/11/01 06:41 AM
                                    AVX and 128-bit FPUs in Zen(Re:Some 'reverse-engineering' of Zen)Anne O. Nymous2015/11/01 08:39 AM
                                AVX and 128-bit FPUs in Zen(Re:Some 'reverse-engineering' of Zen)Matthias Waldhauer2015/11/02 12:26 PM
                                  AVX and 128-bit FPUs in Zen(Re:Some 'reverse-engineering' of Zen)juanrga2015/11/03 02:42 AM
                            Some 'reverse-engineering' of ZenMatthias Waldhauer2015/11/02 10:39 AM
                        Some 'reverse-engineering' of Zenbakaneko2015/10/31 06:28 AM
                          Some 'reverse-engineering' of Zendmcq2015/10/31 07:19 AM
                            Some 'reverse-engineering' of ZenJukka Larja2015/10/31 08:21 AM
                            Some 'reverse-engineering' of Zenbakaneko2015/10/31 09:23 AM
                              Some 'reverse-engineering' of Zendmcq2015/10/31 03:12 PM
                                Some 'reverse-engineering' of Zenbakaneko2015/10/31 04:25 PM
                                  Some 'reverse-engineering' of Zendmcq2015/11/01 06:36 AM
                                    Some 'reverse-engineering' of Zenbakaneko2015/11/01 09:11 AM
                                      Some 'reverse-engineering' of Zendmcq2015/11/01 09:27 AM
                                        Some 'reverse-engineering' of Zenbakaneko2015/11/01 02:35 PM
                                          Some 'reverse-engineering' of Zendmcq2015/11/01 03:52 PM
                                            Some 'reverse-engineering' of Zenbakaneko2015/11/03 02:17 AM
                                              Some 'reverse-engineering' of Zendmcq2015/11/03 03:17 AM
                  Some 'reverse-engineering' of Zenjuanrga2015/10/30 11:43 AM
                    Some 'reverse-engineering' of Zenlurker2015/10/30 01:09 PM
                      Some 'reverse-engineering' of Zenjuanrga2015/10/31 05:58 AM
                        Some 'reverse-engineering' of Zenlurker2015/10/31 07:07 AM
                          Some 'reverse-engineering' of Zenjuanrga2015/10/31 11:50 AM
                            Some 'reverse-engineering' of ZenPoindexter2015/10/31 01:47 PM
                              Some 'reverse-engineering' of Zenlurker2015/10/31 03:06 PM
                                Some 'reverse-engineering' of ZenPoindexter2015/10/31 04:37 PM
                                  Some 'reverse-engineering' of Zenlurker2015/11/01 02:46 AM
                                  Some 'reverse-engineering' of Zenjuanrga2015/11/01 07:16 AM
                                    Some 'reverse-engineering' of ZenMaynard Handley2015/11/01 05:33 PM
                                      Some 'reverse-engineering' of Zenjuanrga2015/11/02 04:06 AM
                                        Zen transistor countHeikki Kultala2015/11/04 12:30 AM
                                          Zen transistor countjuanrga2015/11/05 04:34 AM
                                    Some 'reverse-engineering' of ZenSymmetry2015/11/02 05:56 AM
                                      Some 'reverse-engineering' of ZenDavid Hess2015/11/02 06:16 AM
                                      Some 'reverse-engineering' of Zennobody2015/11/02 07:19 AM
                                        Some 'reverse-engineering' of ZenJukka Larja2015/11/02 08:34 PM
                                          Some 'reverse-engineering' of Zennobody2015/11/03 12:35 AM
                                            Some 'reverse-engineering' of ZenJukka Larja2015/11/03 01:41 AM
                                              Some 'reverse-engineering' of Zennobody2015/11/03 04:10 AM
                                                Some 'reverse-engineering' of ZenJukka Larja2015/11/04 01:52 AM
                                            Some 'reverse-engineering' of ZenKlimax2015/11/03 01:47 AM
                                              Some 'reverse-engineering' of Zennobody2015/11/03 03:19 AM
                                                Some 'reverse-engineering' of ZenKlimax2015/11/03 11:09 AM
                                          Some 'reverse-engineering' of ZenBanana_Comedown2015/11/04 10:17 AM
                                            Some 'reverse-engineering' of ZenJukka Larja2015/11/05 02:51 AM
                                              Some 'reverse-engineering' of ZenBanana_Comedown2015/11/05 12:23 PM
                                      Some 'reverse-engineering' of Zenjuanrga2015/11/03 03:13 AM
                                Some 'reverse-engineering' of Zennobody2015/10/31 07:16 PM
                                  Some 'reverse-engineering' of Zenlurker2015/11/01 02:48 AM
                                    Some 'reverse-engineering' of Zensylt2015/11/01 03:07 AM
                                    Some 'reverse-engineering' of Zennobody2015/11/01 10:49 AM
                                  Some 'reverse-engineering' of Zenmd2015/11/01 12:06 PM
                                    Some 'reverse-engineering' of Zenblu2015/11/01 12:59 PM
                                      Some 'reverse-engineering' of Zenjuanrga2015/11/02 04:10 AM
                              Some 'reverse-engineering' of Zenjuanrga2015/11/01 06:00 AM
                                Some 'reverse-engineering' of ZenPoindexter2015/11/01 08:25 AM
                                  Some 'reverse-engineering' of Zenjuanrga2015/11/02 03:47 AM
                                    Some 'reverse-engineering' of ZenPoindexter2015/11/02 04:39 AM
                                      Some 'reverse-engineering' of Zenjuanrga2015/11/02 12:26 PM
                                        Some 'reverse-engineering' of ZenDan Downs2015/11/02 02:12 PM
                                          Some 'reverse-engineering' of Zenjuanrga2015/11/03 02:51 AM
                            Some 'reverse-engineering' of Zenlurker2015/10/31 02:57 PM
                              Some 'reverse-engineering' of Zenjuanrga2015/11/01 06:26 AM
                                Some 'reverse-engineering' of ZenHeikki Kultala2015/11/01 08:57 AM
                                  Some 'reverse-engineering' of ZenMaynard Handley2015/11/01 05:39 PM
                              Some 'reverse-engineering' of ZenUngo2015/11/01 01:05 PM
                  Some 'reverse-engineering' of Zenquzhujian2015/10/31 09:39 AM
                  Some 'reverse-engineering' of ZenPoindexter2015/11/04 05:10 AM
                    Some 'reverse-engineering' of Zenlurker2015/11/05 12:54 PM
                      Some 'reverse-engineering' of Zennobody2015/11/05 02:28 PM
                      The sad status of tech mediajuanrga2015/11/06 04:19 AM
                        The sad status of tech mediaJoel2015/11/06 05:45 PM
                        The sad status of tech mediaMatthias Waldhauer2015/11/07 02:12 PM
                          The sad status of tech mediaJoel2015/11/07 04:40 PM
Reply to this Topic
Name:
Email:
Topic:
Body: No Text
How do you spell avocado?