RE: CPU count vs. CPU clock speed

  • From: "Kevin Closson" <kevinc@xxxxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Thu, 19 Jan 2006 15:58:00 -0800

 is better (just for example) - 10 CPUs at 1GHz each, or 5 CPUs at 2GHz?
Of course for the purpose of discussion we have to assume all other
system components are identical, and since this is an Oracle list, let's
assume we are running Oracle on the server.

10 parts would have more processor Cache, but if all other components
are the same, you might find that 5 at double clock rate are faster
than the 10 due to the probability that the scalability (bus, memc)
would favor fewer processors to start with.

The huge snoopy-bus legacy SMPs went through this in the late 90s.
Go in to a shop with 8 boards at (X)MHz and replace them with 4
at (X*Y)MHz and made customers happy in doing so. However, those
board swaps ALWAYS included better cache parts...

Having more CPUs means more CPUs to handle interrupts, but that
is not always a gian either since the interrupt context often
goes cache cold... 

flippity, floppity


Other related posts: