POWER7's new instruction set "VSX"

M.Isobe (no@sp.am) on 8/5/08 wrote:
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>Potatoswatter,
>
>>A longer pipeline implies more physical registers.
>
>As I wrote in the first post, POWER7 won't have rename registers. So, the number
>of physical registers will be [the number of architected registers] x [the number of threads].
>
>If POWER7 has OoOE cores, there are no need to increase the number of architected registers?

Once again... All we know is that two register files were merged into one. We cannot conclude anything about the pipeline length from this information. You're getting implication backwards. Because frequency is decreasing, pipeline length should be *shrinking*. Nothing in physics says register pressure can't go down.

And the number of architectural registers didn't increase, they just merged two existing files into one space.

I'm not keeping up with the announcements... it would seem that Power7 is in-order because it's very high frequency, and Power6 is too. But that has little to do with these things.