3 Replies Latest reply on Jan 16, 2015 3:52 AM by dipak

    APU vs Discrete GPU

    boxerab

      I am currently testing my kernel on an HD 7700 discrete card.

       

      This 3 year old mid-level card is fast enough for my application.

       

      Carizo is arriving this year; will Carizo OpenCL perf be greater

      than 7700 ?  If not, can anyone comment on when APU perf will be reach

      7700 performance levels?

       

      Thanks!

       

      Aaron

        • Re: APU vs Discrete GPU
          dipak

          Hi Aaron,

          I'm not clear what does it mean "will Carizo OpenCL perf be greater than 7700?". One way, you may simply figure out by comparing both specs (say number of CUs, total number of cores, frequency, GFLOPs, Memory etc.). However, application scope of APU and dGPU may not be same. With Carizo APU, you'll get HSA and OpenCL2.0 (with higher GCN version than HD 7700) support, so you can exploit certain OpenCL2.0 features which may impact the performance significantly over the old HD 7700 dGPU card. So it depends on your usage. IMHO, if you don't want to use any benefits of APU or new features of OpenCL, comparing both the spec. is more intuitive. As Carizo is still not available, it would be difficult to comment about the actual performance differences. But, I can say performance of the APU are getting better day by day and it'll continue in future.

           

          Regards,

            • Re: APU vs Discrete GPU
              boxerab

              Thanks, Dipak.  My use case doesn't benefit from OpenCL 2.0.

              Also, HSA is not an issue for me.

               

              Based in OpenCL 1.2 spec, I am just wondering how the Carrizo perf will compare to HD7700.

               

              The two GPUs have similar number of compute units.

                • Re: APU vs Discrete GPU
                  dipak

                  I guess, you may use a Kaveri APU in this regard for benchmarking the same. Because, as I assume, you can get a idea using Kaveri also. Did you already test it on Kaveri? If so, what was your finding?

                   

                  Regards,