Michael S (already5chosen@yahoo.com) on 8/5/10 wrote:
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>For the application depending mostly on main memory latency E7220+7300 combo is
>almost worst possible representative of C2D family.
>Now, I'd imagine that you were buying these chips because per socket and per core
>they provide the highest memory capacity. That's of course a legitimate reasons.
>But, IMHO, you can't extrapolate comparisons made on such relatively uncommon setup
>to more general C2D vs Nehalem case in which Nehalem still enjoys memory latency
>advantage but, esp on desktop, the difference is much much smaller.

We needed big memory (256GB). Beyond that, I'm in a sizable
corporation where the detailed purchasing choices are
taken elsewhere, in a separate organization :-(
It doesn't surprise me that we've got a
Core-based machine that kinda sucks. But then we've also
got a Nehalem-based machine that kinda sucks, because
the state of the art is 32nm Westmere/Gulftown at up
to 3.6GHz. So in that sense the playing field is level.

Anyhow, I think another possible explanation of Intel's
choices is that Core2 architecture was optimized for
45nm and at most 4 cores on a die; whereas Nehalem was
optimized for 32nm and up to 6 cores on a die. And
that leads to different choices about cache sizes and
latencies and all kinds of other stuff.

We do also have some Core2 3.2GHz blades with smaller
memory configurations, and those seem to beat our
Nehalem 2.66GHz equivalents on some benchmarks. Though
they also seem really flaky to me, so I avoid them
as much as possible.