> From: Bob Friesenhahn [mailto:bfrie...@simple.dallas.tx.us] > Sent: Wednesday, July 11, 2012 10:06 AM > > On Tue, 10 Jul 2012, Edward Ned Harvey wrote: > > > > CPU's are not getting much faster. But IO is definitely getting faster. It's > best to keep ahead of that curve. > > It seems that per-socket CPU performance is doubling every year. > That seems like faster to me.
It's a good point. It's only *serial* computation that isn't increasing much anymore. But computing hashes for a bunch of independent blocks is a parallel computation operation. For now, they're able to keep parallelizing via more cores. Still, I wonder how many more years this can continue? The reason the serial computation isn't increasing much anymore is simply because the transistors etc have gotten small enough that they can't really increase clock speed much more. If you have a 3.0 Ghz clock, how far does light travel in one hertz? About 10cm. All the transistors, capacitors, wires etc need time to react and stabilize before the next clock cycle... For now, they're still able to keep making larger dies, with more cores on them, and they're certainly developing layering and 3-D technologies, which will certainly allow the number of cores to keep growing for some time to come. But there is a limit somewhere. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
