I was referring to the effects of cache+memory layout characteristics. On the E4500 I use, each CPU has 8M of cache and with 14 CPU's thats a lot of active process space that can stay in cache. The memory difference comes from the how many non-contigues memory requests are made and can be handled quickly. DDR-400 is great for many applications, but the more random the access patterns, less of an advantage it has. That is where the heavy load on a system makes a big difference. What architecture is best is very dependent on what the application is and the load characteristics.
I do agree that there are many places where the Sun system suck compared to the current the current competition. But as the load and number of processes climb, the UII & UIII system performance curves still show significantly better performance then one would expect from such outdated technology. On Tuesday 07 October 2003 21:51, Andrew Sharp wrote: > On Tue, Oct 07, 2003 at 06:45:26PM -0500, Steven Wilcoxon wrote: > > My experiances with dual and quad x86 systems that should blow an E4500 > > out of the water have shown me that in multiprocessor applications, as > > the load increases, the E4500 handles the loading much better. > > > > My personal opinion as to why is related to the CPU cache and memory > > architecture. In x86, each CPU has a smaller amount of cache and then > > bottlenecks at the memory. In the E4500, even though each CPU is slower, > > the higher number of CPU's and the layout of the memory makes it much > > harder to slow down. > > > > Now I need to get my hands on a good Quad Opteron to see how that feels! > > When was the last time you tried a dual xeon w/2MB cache with a > real server chipset? No need to plunk down the bones for an Opteron. > And let's not forget the 2MB cache P4 that Intel just released. That and > dual channel DDR 400 memory, and the memory on these systems is faster > than the cache on all but the latest US3 systems, so the memory > bottleneck argument is pretty much over, too. > > a <SNIP> -- S.W. aka Learner http://www.TerminusPoint.com
