Adrian (a.delete@this.acm.org) on August 30, 2022 10:23 am wrote:
> me (me.delete@this.me.com) on August 30, 2022 8:17 am wrote:
> > > The Ryzen 9 7950X is expected to have a cost of around $0.50 per Gflop/s, which approximately
> > > matches the lowest computation cost that has ever been provided by GPUs.
> > >
> > > Also the expected value for Gflop/s per watt is about the same as it was
> > > for the best GPUs before their transition to FinFET CMOS processes.
> > >
> >
> > If I did the math right the 7950X @ 5 Ghz all core would be 1.2 TF for fp64.
> > Even with it being gimped, the Navi 21 GPUs do about that. MI250X does 47.
>
>
>
> It is true that a Radeon RX 6900 XT has a similar FP64 throughput as expected for 7950X.
>
> However, it costs $800 and it consumes 300 W, so it is both more expensive and more power hungry.
>
> To be an attractive alternative to a CPU, a GPU needs at least
> a double performance, both per dollar and per watt.
>
>
> Of course I would like a MI250X, but that is Unobtainium.
>
>
> It remains to be seen which will be the specifications for the soon to be launched NVIDIA RTX 4000 series and
> AMD RX 7000 series, but I doubt that any of those can offer competitive performance for FP64 computations.
>

Not all interesting/important fp codes are fp64. For fp32 the rx-6900xt has
a peak rate of 23 Tflops (16 fold the fp64 rate) which is half of the mi250x.
So, for some a consumer GPU may indeed proove to be attractive.