Hi there I've been reading through the MS documentation on Performance and capacity planning and I'm now pretty confused http://technet.microsoft.com/en-us/library/cc261795(office.12).aspx The gist of it seems to be: They created a test environment - several farm configurations were used for testing, ranging from a stand-alone computer to eight Web servers with single and clustered computers running Microsoft SQL Server 2005. Testing was performed with eight client computers simulating from 32 through 256 user connections So how do they get these test results: Farm configuration RPS Total number of user connections Light usage Typical usage Heavy usage Extreme usage Mix Read Mix Read Mix Read Mix Read Mix Read 1 by 1 50 100 90,000 180,000 50,000 100,000 30,000 60,000 15,000 30,000 2 by 1 99 185 178,200 333,000 99,000 185,000 59,400 111,000 29,700 55,500 3 by 1 115 265 207,000 477,000 115,000 265,000 69,000 159,000 34,500 79,500 4 by 1 120 275 216,000 495,000 120,000 275,000 72,000 165,000 36,000 82,500 5 by 1 136 280 244,800 504,000 136,000 280,000 81,600 168,000 40,800 84,000 6 by 1 130 280 234,000 504,000 130,000 280,000 78,000 168,000 39,000 84,000 7 by 1 134 290 241,200 522,000 134,000 290,000 80,400 174,000 40,200 87,000 8 by 1 130 280 234,000 504,000 130,000 280,000 78,000 168,000 39,000 84,000 Where do they get the "total number of user connections" up in the 100,000s when they simulated only 256 user connections? How is RPS calculated? What is measured and what is derived? I understand that they've used different farm configurations but what did they run against each config and how are the results calculated? If anyone can shed some light on this it would be great Cornelius had a go but his SPCAP is now nowhere to be found - SharePoint Capacity Planner is being discontinued as a result of Microsoft System Center Capacity Planner (SCCP) formally being discontinued His useful article is here http://www.cjvandyk.com/blog/Lists/Posts/Post.aspx?ID=100 he tries also to make sense of the MS documentation but ultimately I still can't figure out how the formulas are supposed to work - especially with SQL clusters and high numbers of users (over 100,000) Anyone got any advice? Does anyone out there use some modelling for capacity planning or is everyone doing what we've been doing which is just keep throwing hardware at the environment until the customer stops complaining Cheers Jonj