Datatribe Softwerks, Ltd.

Comments are currently disabled. Feel free to use the contact form.

Reader Contributions:

Jerry (10/06/2008 12:40 PM)

Minor footnote: The Diff column is column b / column a as a % - so not really diff so much as time B as a % of time A - but that's a very long winded (if not more accurate) column heading.

Derek Reynolds (10/06/2008 02:38 PM) e-mail

WOW. "Impressive" to say the least.

Derek Reynolds (10/06/2008 03:19 PM) website / e-mail

Hey Jerry,

As you know I'm an avid SameTime 8.x user. As much as it's a great IM client, the one thing that I do commonly complain about is how slow it is.

After reading both your article as well as Andrews I got intrigued and thought maybe I can obtain the same some sort of performance gain making a similar change to SameTime as it also sits on top of Eclipse.

After peeking through a few hundred files I managed to track down the file that manages the vmarg.XmX within SameTime.

It is located here:
C:\Program Files\IBM\Lotus\Sametime Connect\rcp\eclipse\plugins\com.ibm.rcp.jcl.desktop.win32.x86_6.1.1.200711051602\jvm.properties

Contents listed below

###############################################################################
# Licensed Materials - Property of IBM
# 5724-M20
# ? Copyright IBM Corp. 2006 All Rights Reserved.
###############################################################################
vmarg.Dibm.jxes.jar2jxeOptions=-Dibm.jxes.jar2jxeOptions=-nog
vmarg.Dosgi.java.profile=-Dosgi.java.profile=jclDesktop-6.1.profile
vmarg.Xdump=-Xdump:heap:events=user,request=compact+exclusive+prepwalk
vmarg.Xgcpolicy=-Xgcpolicy:gencon
vmarg.Xms=-Xms12M
vmarg.Xmx=-Xmx256m
vmarg.Xquickstart=-Xquickstart
vmarg.DjxeCacheDir=-Dibm.jxes.jxeCacheDir=${rcp.home}/rcp/jxes
vmarg.Dosgiext=-Dosgi.framework.extensions=com.ibm.rcp.core.logger.frameworkhook,com.ibm.jxesupport


Similar to Andrews/Your article just change the "vmarg.Xmx=-Xmx256m" to "vmarg.Xmx=-Xmx1024m" . Just make sure you close SameTime down before making these changes.

I saw an immediate performance gain in the load time. Once loaded the UI seemed a little snappier too. SameTime although still bloated is now alot faster than it was.

Talk to you soon,
-Derek

Jerry (10/06/2008 08:35 PM)

Wow, cool Derek. Thanks for sharing that. I'll pass that on at work. I think we're using the embedded ST client, so the same JVM setting we already employed had an effect there as well, but some folks are not yet. Very cool.

One thing we've all I think been wondering though, is - why isn't this dynamically allocated at install time?

Jesper Kiaer (10/07/2008 04:10 AM) website /

first, I have not tried the setting myself yet. I does seem logical that startup is better which as different users have suggested.

But beware tuning the JVM is not a simple as turning a knob.

One of the problems of raising the maximum Heap size to a large size is that much time will be spent on GC later on. So you may get faster load times, but when you have worked a bit with the Notes client it may in fact be slower than with the smaller setting

Lots of GC is of course also happening if the heap is too small.

For the non faint-hearted you can dive into the JVM options here:

{Link}

brgds Jesper Kiaer

Jerry (10/07/2008 06:15 AM)

Prudent advice, Jasper. Thanks!

Derek Reynolds (10/07/2008 12:22 PM) website / e-mail

I found a few articles that stated that on processes that are resource intensive to match the Xmx value with the Xms.

{Link}

Today I changed both the Xms and XMX to be the same (1024MB) and saw yet another performance boost, mostly on load of SameTime.

Originally:
vmarg.Xms=-Xms12M
vmarg.Xmx=-Xmx256m

Now:
vmarg.Xms=-Xms1024M
vmarg.Xmx=-Xmx1024m

Jerry (10/07/2008 02:14 PM)

Yeah, per one of the guys here, XMS is the heap Start size and XMX is the max size.

Makes sense - no time wasted growing the heap dynamically.