Second Life Assignment
In Second Life to get the most improvement from fast storage we need to think about what part of the viewer uses storage most often and how much data it needs.
The Second Life Viewer takes up about 167MB of storage on my Windows 7 & 10 machines. Firestorm-64 takes up about 280MB. My SL Viewer cache is about 10GB on Win 7 and Firestorm’s about 4GB. The difference is because of the cache size settings I have in each viewer. Way more storage is used by the caches.
When a program launches the computer is reading the program files from storage. So, launch time is seriously dependent on storage speed. When we open a panel in the viewer it goes to storage to get the information on how to draw the panel and populate it. Storage affects how quickly panels can open and populate. Once the viewer loads the information into memory the viewer has little interaction with the program files in storage. Close a panel and the viewer can release that memory and of course then have to go to storage if the panel is reopened. But how often are you doing that?
You can press Cntrl-Shift-3 to open the Texture Console and watch the viewer loading textures it needs to render a scene. This will give you an idea of the near constant use of the cache, dozens of times per second. Also the viewer is downloading information, textures, and mesh and storing that data, may be hundreds of times per second. The cache is in use far more than any other part of the viewer system.
So, we want the program and caches on the fastest storage possible. The optimum performance will come from having both program and caches on the SSD. But, you need a big RAM Drive. Having the viewer program on a SSD and the cache in a RAM Drive is nearly as good. The next best is having the programs on a fast 6Gb/s hard drive and the cache on the SSD, which is what I decided on because of other work related stuff. With the viewer loading in >10 seconds from a 6Gbps drive (actual performance = 150MB/s) there are very few seconds to save by using faster media.
Another consideration with RAM Drives is computer crashes. I keep the viewer’s chat logs on hard drive storage to prevent loss, SSD or HD. That may not matter to you. But, a computer crash can drop the RAM Disk. Whatever you have added to a cache in RAM Drive just previous to the crash will likely be lost. Since I often collect meeting chat logs, that would not be good.
Viewer crashes won’t likely cause the RAM Drive to disappear. But, a computer blue screen, shutdown, or other serious system crash most likely will.
There are some advantages to using SSD via SATA over spinning disks via SATA. Seek and latency times are smaller. Too small a difference, I thought, to justify the cost of a SSD. My hardware doesn’t allow me to test that idea. I found Tom’s Hardware had done that test in 2013. See: Is A SATA 3Gb/s Platform Still Worth Upgrading With An SSD? TL:DR take away is you get about a 25% increase in performance with an SSD over a fast HD, in their case a Western Digial VelociRaptor and a high end (at the time) Samsung 840 Pro.
You can get software to test your storage devices transfer rate. Like most things computer the performance we get from any device is a collection of factors. The only way we can know what level of performance we are getting from our particular collection of parts is by measuring it.
Free testing software is here: 10 Free Tools to Measure Hard Drive and SSD Performance (Windows)
By measuring it we know if we got things right or something is messed up and slowing us down.