Online OsiriX Documentation/Making OsiriX run faster
There are two limitations to OsiriX: memory and processor power.
- 1) Memory:
- OsiriX requires a lot of memory if you try to open a large series of images! If OsiriX does not have enough memory, MacOS X will try to free memory by using the “Virtual Memory” (VM) mode: it will use your hard drive as RAM... But VM is about 1000 times slower than RAM!! You see the problem... Here is how to compute memory the amount you need: do the following simple calculation for the number of images you want to view and handle at the same time:
- Memory required = Height X Width X Number of images x 4 / 1048576
- For example: 512 x 512 x 100 x 4 / 1048576 = 100 MB of RAM for 100 CT images
- This means that you need at least 100 MB of RAM ONLY for your 100 CT images. MacOS X requires a minimum of 256 MB to work “normally”. You will need at least 256 + 100 MB = 356 MB to avoid Virtual Memory mode.
- 2) Processor power:
- OsiriX needs high processing power for 3D reconstruction: MIP and Volume Rendering. OsiriX is a multithreaded application that can use all of the processors available in your computer. If you want the best performance you should buy a quad G5 or a MacPro intel quad!
- Another solution is to use a computer cluster with the Apple X-Grid /MPI technology. Run and install the package. You then need to install the “OsiriX plugin”: copy it in the “Plug-ins” folder of “Xgrid” folder located in your “Library” folder. More information about this technology in future releases.
- Another solution would be to use a VolumePRO PCI graphic board from TeraRecon. This solution is currently under investigation to make OsiriX run faster than a Vitrea3D workstation! All 3D reconstructions in OsiriX are based on VTK and VTK fully supports the VolumePRO graphic board...