Cache What Is It and What Does It Do?

Good Monday Folks

I was thinking what better time to share viewer Cache tips and tricks for firestorm these pertain to the SL viewer as well please check Second Life Viewers wiki page for that info. February is a great time to spring clean your system as well as sl viewer and Inventory.


In SL-relevant lay terms, the cache is a time-saving device. When you need to see a texture in SL or get something from your inventory, it happens more quickly if the item is already cached than if you need to download that asset from the SL servers. If you wander into an area with a lot of textures you don’t already have cached, it’ll take some time for your computer to capture them all and store them in your cache. Under normal circumstances, you want to leave those textures there (that is, don’t clear cache) so that the next time you’re in that location, you don’t have to wait for everything to download again — it’ll already be available to you on your hard drive. Same with inventory. When your inventory cache is full and not experiencing any issues, then when you log in to SL, all your inventory will be right there. If it’s been cleared, then you have to wait for everything to get fetched from the SL servers again before you can see it and use it. For a more technical explanation, see

It is commonly believed that clearing cache can help with a multitude of issues, but really it’s only helpful for a handful. We do not recommend clearing cache unless you are having an issue that cannot be solved by other means.

We get asked a lot about what to set cache size to; the simple answer is to set it to the maximum possible in the viewer, as long as you have room on your hard drive. In Firestorm, the cache size can be increased to 9,984 MB. We do have a way to allow you to have a larger cache, but it requires extra hardware and software. If you are interested please see Squid Proxy Cache

Be picky about why and when you clear your cache. Clearing cache doesn’t fix everything. In fact, it doesn’t fix nearly as many problems as many people seem to think. And doing it when it’s unnecessary has its drawbacks, including slower initial rez times and excess bandwidth being pulled, which can create sim lag. “Clear your cache” is something we’ll recommend ONLY if the problem appears to be cache-related: that is, pertaining to textures or, once in a while, inventory. A full cache is almost always better than an empty one. Here is a basic “DO” list:

When NOT to clear your cache

Don’t clear cache as a matter of routine maintenance. If there isn’t something actually wrong with your cache, then this does nothing beneficial.

Don’t clear it for problems unrelated to the cache. For example, it won’t help for:

  • teleport issues
  • asset upload issues
  • movement or communication problems
  • most kinds of lag
  • most kinds of crashes
  • a vast majority of bake fails
  • any problems concerning music, video or voice.

There are some exceptions (e.g., crashes related to textures), but in many cases, other causes are more likely, and clearing cache doesn’t have to be the first measure. The list above is by no means exhaustive; its purpose is to provide an idea of how many common issues are unrelated (or only occasionally related) to cache.

When to clear your cache

  • When many textures appear as distorted rainbows or psychedelic colors, you may choose to clear your texture cache.
  • When your inventory is not loading fully, you may choose to clear your inventory cache.
  • A cache clear may be part of performing a clean install of the viewer.

Note that often, only part of your cache needs to be cleared. While you can clear your full cache by clicking the button in Preferences, it is not hard to perform the needed part of the cache clear manually. You can find your cache folder by going to Preferences and then Network & Files → Directories. Click the “Open” button alongside the path to your cache files location. In there you’ll see some files ending with .inv.gz – these are your inventory cache files – and a folder containing your texture cache. More information is here for Firestorm.

Have a great week from all of us at Zoha Islands and Fruit Islands/Eden