[The original post is by a nonsubscriber and can seen on nabble]
http://osgeo-org.1560.n6.nabble.com/Same-Configuration-Different-computer-very-slow-tp5028863p5029753.html
Original poster, please subscribe to this list or your posts will not be delivered. (You were just lucky that Christian reads via nabble and was kind enough to respond.)
On 25/01/13 13:00, cmaul wrote:
Yep, every 64-bit address is twice as long as a 32-bit address. 2Gb address
space can be addressed with 32-bit, hence using 64-bit you have a lot of
waste just for addressing your objects.
I doubt that you have only 2Gb RAM on your Mac. So, 64-bit systems are a
complete waste and usually slower, if you want to assign only 2 Gb of RAM.
With larger memory spaces a 64-bit system will fly.
I am not sure 64-bit is the problem. Both machines are using 64-bit.
Since Java 6u23, 64-bit (amd64) Oracle VMs default to using Compressed OOPs, which combine the memory size advantage of 32-bit pointers with the performance advantage of the amd64 instruction set and only a slight overhead:
http://docs.oracle.com/javase/7/docs/technotes/guides/vm/performance-enhancements-7.html#compressedOop
64-bit VMs are slower on startup because they only support server mode, which is optimized for maximum performance for long-running applications; tiered compilation reduces this overhead but it is still there for short-running applications.
Back to the original question:
The two Windows Server 2008 machines are running in two different virtualisation implementations, one fast in parallels on a mac (WS2008 R2) and one unexpectedly slow in vmware on a non-mac (WS2008 not R2). Both 64-bit Java 6.
Have you tried running them both on the same virtualisation implementation, on the same hardware? This would be a direct test of R2 versus non-R2.
Performance of virtual machine systems can vary wildly, depending on host factors such as filesystem virus scanning on the host, host hardware (HDD versus SSD), host filesystem type (HFS, NTFS, ext4), hardware virtualisation support such as VT-x and VT-d, and host software implementation. Best to compare apples with apples by comparing R2 and non-R2 on the same machine with the same virtualisation implementation.
What version of VMWare are you using?
Kind regards,
--
Ben Caradoc-Davies <Ben.Caradoc-Davies@anonymised.com>
Software Engineer
CSIRO Earth Science and Resource Engineering
Australian Resources Research Centre