Can you try increasing the SOC maximum heap size (in MB) from its default value of 64 to 128. Here are the steps to do this.
1. In a web browser, navigate to http://<Your Server Name>:6080/arcgis/admin. 2. Log in to the ArcGIS Server Administrator Directory with an administrators account. 3. Click machines. 4. Click the link <Your Server Name>.<domain>.com. For example, a link may appear as server1.esri.com. 5. On the page Server Machine Properties, click the edit link. 6. Increase the value of App Server maximum heap size (in MB). 7. Click the Save Edits button to finish editing.