can anyone informed put some light on the question whether a program I write today with CUDA 2.3 for a 1.3 device will more or less scale in speed according to the specs of the upcoming G300? There are two reasons I ask. First of all from the g80/g92 to g200 it is quite straight forward to expect relatively good scaling since those are build of (more or less) the same basic blocks. But now I read that for the G300 we will not have anymore a SIMD but a MIMD processor (though one could argue that todays GPUs are already MIMD chips build from SIMD blocks). I also read that double precision is organized different to todays architecture.
Now, can I expect that a program, which I write for todays SIMD architecture (especially double precision code), scales relatively good to the G300? Meaning: if I reach now like 80% peak performance will it be close to 80% peak performance on the G300 as well [assuming I got enough threads running]?. In that scenario I would expect that the MIMD architecture just let me things do I can’t (or better shouldn’t) do now (i.e. no problems with branching) while code written with SIMD in mind would still run well.
I ask because I don’t want to start a project now which will be obsolete as soon as I finished it.