Gautam Sewani wrote:
That is very bad news indeed :-( .
Can anyone confirm this with some testing? (I am using a Core duo, and
don't have access to Core 2 Duo.)
Regards
Gautam
On Thu, Jun 5, 2008 at 7:26 PM, Frédéric Bastien <nouiz@xxxxxxxxx> wrote:
Hi,
With processor before core2 from intel, their was a bottleneck in the
CPU that make all sse instruction being split in two. So as you have
only two double in a sse instruction and if you have a processor with
such a bottleneck, I see only 1 way to have a speed up. Use float
instead of double. I know, this is not always an option. To my
knowledge prescott cpu have this bottleneck.
bad mix of top and bottom posting, some elided
I don't see how this relates to the beginning of the thread. It's true
that some CPUs in the past (pentium-m, AMD before Barcelona) always split
128-bit operands into 2 64-bit operands. This doesn't mean you should
avoid parallel SSE2, although it may reinforce the point that you should
consider whether you are going about your task the best way.
