Barney - that is a very very helpful explanation. On Wed, Apr 7, 2010 at 6:41 PM, Mark A. Kruger <[email protected]>wrote:
> > Barney - you are my new hardware hero... nice explanation :) > > -Mark > > -----Original Message----- > From: Barney Boisvert [mailto:[email protected]] > Sent: Wednesday, April 07, 2010 5:02 PM > To: cf-talk > Subject: Re: Is ColdFusion request speed based on CPU clock speed alone? > > > The instruction width doesn't change the number of instructions you > can run at any given time. Certain operations can be done more > efficiently (for example, adding small numbers can be done > in-instruction, rather than having to load stuff into registers > first), but in general it's not going to matter. You're not going to > magically get parallelism with 64-bit. > > And it has nothing to do with Java (or at least very little). > Servicing an HTTP request is pretty much a top-to-bottom procedure, > there isn't a way to easily divide it up into bits of work that can be > run in parallel. But since HTTP servers are typically servicing > multiple concurrent requests, the overhead of trying to parallelize a > single request is hugely outweighed by simply parallelizing separate > requests. If you've got a multicore, multiprocessor machine, it's > exceptionally unlikely you're going to be one request at a time, so > trying to optimize that use case is of little value. > > To go back to your original scenario. If 1 request to your machine > with the 5540s takes 261ms, then I'd expect 16 simultaneous requests > to also take about 260ms. The cores/processors will allow those 16 > requests to all run in parallel with all the CPU they can use. > Contrast this with your 5160s, which can run 1 request in 196ms, but > should take around 392ms to service those same 16 concurrent requests > (because it can service 8 at a time, so the second 8 wait while the > first 8 are processed, and then they get some CPU). And it's probably > actually worse than that because unless you have your JVM/CF tuned to > your request load there will probably be context switches between > threads so you'll loose a bit of efficiency trying to run 16 requests > on 8 execution threads. > > cheers, > barneyb > > On Wed, Apr 7, 2010 at 2:41 PM, John Foster <[email protected]> > wrote: > > > > Do you think a 64 bit OS or CF9 would allow my apps to better utilize > newer CPU's , or would I still be bottlenecked by java to a single thread / > request? > > > > > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Want to reach the ColdFusion community with something they want? Let them know on the House of Fusion mailing lists Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:332745 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/groups/cf-talk/unsubscribe.cfm
