# why cpu goes 100% with 400 users?
**URL:** https://community.wowza.com/t/why-cpu-goes-100-with-400-users/38498
**Category:** Wowza Streaming Engine
**Created:** [May 24, 2012, 5:56pm UTC](https://community.wowza.com/t/why-cpu-goes-100-with-400-users/38498 "2012-05-24T17:56:49Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Sunil\_Chelaramani1](https://community.wowza.com/u/Sunil_Chelaramani1)
#### Post date: [May 24, 2012, 5:56pm UTC](https://community.wowza.com/t/why-cpu-goes-100-with-400-users/38498/1 "2012-05-24T17:56:49Z")
I see CPU usage goes 100% with just 400 users on Windows 2003 machine that is capable of handling load of 1000 WM streams users.
Server Config:
Xeon 3.0 + 8 GB Ram + 300 GB Sata + 1 Gig NIC
Windows 2003 Enterprise x64
Wowza Media Server 3 Monthly Edition 3.1.1 build1479
java version “1.7.0\_04” (JDK is installed)
Java™ SE Runtime Environment (build 1.7.0\_04-b22)
Java HotSpot™ 64-Bit Server VM (build 23.0-b21, mixed mode)
We have followed all performance tunning steps as suggested in below article.
[https://www.wowza.com/docs/general-tuning](https://www.wowza.com/docs/general-tuning)
----- setenv.bat -------
set \_EXECJAVA=java
set JAVA\_OPTS=-Xmx5000M
rem If running JDK, uncomment to run server environment (faster)
set JAVA\_OPTS=%JAVA\_OPTS% -server
rem Better garbage collection setting to avoid long pauses
set JAVA\_OPTS=%JAVA\_OPTS% -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:+UseParNewGC -XX:NewSize=512m
* * *
------------ WowzaMediaServer-Service.conf ----------
# If running JDK, uncomment to run server environment (faster)
wrapper.java.additional.9=-server
wrapper.java.additional.10=-XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:+UseParNewGC -XX:NewSize=512m
# Uncomment to force Java to use specific language settings
#wrapper.java.additional.10=-Duser.language=en
#wrapper.java.additional.11=-Duser.country=US
* * *
Please help!
S
---
### Author:  [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)
#### Post date: [May 25, 2012, 9:21pm UTC](https://community.wowza.com/t/why-cpu-goes-100-with-400-users/38498/2 "2012-05-25T21:21:24Z")
Try this without “-XX:+CMSIncrementalMode”, just use this:
```auto
-XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:NewSize=512m
```
This follows recent changes to the Tuning Guide:
[https://www.wowza.com/docs/how-to-do-performance-tuning](https://www.wowza.com/docs/how-to-do-performance-tuning)
Richard
---
### Author:  [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)
#### Post date: [May 29, 2012, 5:43pm UTC](https://community.wowza.com/t/why-cpu-goes-100-with-400-users/38498/3 "2012-05-29T17:43:21Z")
Do you have any modules doing HTTP or JDBC calls?
Richard
---
### Author:  [@Jason\_Hilton](https://community.wowza.com/u/Jason_Hilton)
#### Post date: [May 30, 2012, 11:00am UTC](https://community.wowza.com/t/why-cpu-goes-100-with-400-users/38498/4 "2012-05-30T11:00:31Z")
Hi
Can you send the Wowza logs from start-up it shows the Thread pools etc…
Example :
480
320
The rest of the VHost.xml should look like this using a quad core processor :
4
8
4
4
Jason
---
### Author:  [@Sunil\_Chelaramani1](https://community.wowza.com/u/Sunil_Chelaramani1)
#### Post date: [May 27, 2012, 8:44am UTC](https://community.wowza.com/t/why-cpu-goes-100-with-400-users/38498/5 "2012-05-27T08:44:17Z")
Richard,
Thanks for your quick response.
I tried suggested changes but no improvement. Any other tip/tweak?
Thanks,
S
---
### Author:  [@Sunil\_Chelaramani1](https://community.wowza.com/u/Sunil_Chelaramani1)
#### Post date: [May 30, 2012, 1:15am UTC](https://community.wowza.com/t/why-cpu-goes-100-with-400-users/38498/6 "2012-05-30T01:15:01Z")
No, it is simple Origin/Edge Setup where users are only connecting to Edge Server. No additional modules on it.
---
### Author:  [@Sunil\_Chelaramani1](https://community.wowza.com/u/Sunil_Chelaramani1)
#### Post date: [May 30, 2012, 6:05am UTC](https://community.wowza.com/t/why-cpu-goes-100-with-400-users/38498/7 "2012-05-30T06:05:19Z")
Jason,
Sorry but where can I find startup log?
Thanks,