>>
>> Hi Dan,
>>
>> Yes, actually, I already know that parallel performance will be much
>> improved, however, I was expecting more improvement on single threads as
>> well, since the specs say that it takes 40 clock cycles just to access the
>> FPU on the T1, but something like 6 clock cycles on the T2. So just from
>> that perspective it seems like there should be a significant improvement for
>> single threads, not just parallel performance. At least that's the way I
>> read the docs from Sun on this. At any rate, my expectations here are
>> clearly wrong, and I guess I'd just like a better understanding of why I'm
>> getting it wrong.
Hi Rod,
I wouldn't expect any noticable difference running a single query
that is taking anthing than less than a second if the only technical
difference is that it takes 34 less clock cylces to access the FPU,
thats 34 clock cycles on a cpu with <1GHz clock. The additional FPUs
and reduced clock cycles to access the FPUs simply improve preformance
when running mutliple threads that require FPU calculations, ie almost
no overhead up to 8 simultaneous FPU calculations and less overhead
when the number of simultaneous calculations goes over the number of
physical FPUs due to the reduced clock cycles to access a FPU.
In general my understanding of the T1 vs T2 architectures is that the
CPU and FPU cores are essentially the same regarding preformance per
thread but with additional threads per core and additional FPUs and
some other nice bits like on board Gig Ethernet and support for 2
socket servers, plus any bump in the clock speed over the older boxes
obviously.
thanks Andy.
