Hello: we also wish to convert out 32bit dual cores to 64bit dual cores to run java applications (multiple instances with large JVM memory) but people advice that 64bit are 20 - 30% slower than the 32bit with smaller JVM. why? and if true how to overcome??
thanks Peter Stavrinides wrote: > > Some of arguments presented hold some truths, but look at the bigger > picture... the point is that 64bit is a superior architecture to 32 bit, > but it is still maturing... the reasons for this are both hardware and > software related... the way we write programs will have to change to > take advantage of the new architecture, and the current generation of > hardware will no doubt mature to realize the potential of 64bit > architecture. > > 32 bits processors can represent numbers up to 4,294,967,295 while a > 64-bit machine can represent numbers up to 18,446,744,073,709,551,615. > For modern hardware to take advantage of the processing power of the 64 > bit architecture a system must have a minimum 4GB Ram, but probably > needs significantly more and more importantly the CAPACITY to take full > advantage of it, allocating it to running processes, with less there is > potential for lag. > > 64bit machines have been around since the 60's but only now are software > and hardware vendors supporting it for the mainstream market. So is > 64bit better than 32bit right now? the answer is yes, a 64-bit processor > has more technology, a better design with more transistors, thus faster > speeds are possible. This is currently where the true benefit of > switching to a 64-bit processor lays, it has nothing to do with the > memory address space, which is exactly that, just space for more complex > computations. > > Peter > > > Alexey Solofnenko wrote: >> No, each of two 4GB processes will have only a half of the objects >> under the same load. And I heard that GC does not scale linear with >> heap size. And this is without multi-threading performance >> considerations. As usual, your mileage may vary and only tests can >> tell for sure. >> >> - Alexey. >> >> Caldarale, Charles R wrote: >>>> From: Alexey Solofnenko [mailto:[EMAIL PROTECTED] Subject: Re: >>>> Tomcat with 8 GB memory >>>> >>>> I was under impression that GC does not scale linearly. That means >>>> one 8GB process will be slower than two 4GB processes. >>>> >>> >>> Not true. The time of a full GC using modern algorithms depends mostly >>> on the number and type of live objects, not the amount of heap space. >>> The number and type of live (reachable) objects stays relatively >>> constant for most application once the ramp-up period is over. >>> Consequently, running a single JVM with the largest heap you can fit in >>> the process space is the most efficient from a GC point of view. (Of >>> course, there are plenty of other reasons not to put all your eggs in >>> one basket.) >>> >>> - Chuck >>> >>> >>> THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY >>> MATERIAL and is thus for use only by the intended recipient. If you >>> received this in error, please contact the sender and delete the e-mail >>> and its attachments from all computers. >>> >>> --------------------------------------------------------------------- >>> To start a new topic, e-mail: users@tomcat.apache.org >>> To unsubscribe, e-mail: [EMAIL PROTECTED] >>> For additional commands, e-mail: [EMAIL PROTECTED] >>> >> > > -- > Peter Stavrinides > Albourne Partners (Cyprus) Ltd > Tel: +357 22 750652 > > If you are not an intended recipient of this e-mail, please notify the > sender, delete it and do not read, act upon, print, disclose, copy, retain > or redistribute it. Please visit http://www.albourne.com/email.html for > important additional terms relating to this e-mail. > > > > --------------------------------------------------------------------- > To start a new topic, e-mail: users@tomcat.apache.org > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > > -- View this message in context: http://www.nabble.com/Tomcat-with-8-GB-memory-tf4149367.html#a11853960 Sent from the Tomcat - User mailing list archive at Nabble.com. --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
