To increase the longevity of your SSD you want to reduce your disk writes. One way to achieve that is to use a memory cache instead of a disk cache (it will then store the cache in your RAM rather than on a disk, which is also a lot faster).
This also becomes highly relevant when you want to speed up your server, because a disk cache will always be slower than a memory cache.
I am going to explain here to use the memory cache in Firefox. Similar tutorials will follow for Chrome and IE9, possibly Opera.
1. Step Open Firefox
2. Step Enter about:config into the address bar where you normally enter addresses into – this is the ultimate config panel in Firefox
3. Step Enter browser.cache.disk.enable into the Filter
4. Step As you can see the value is by default set to true
5. Step Double-click on the entry to set it to false
6. Step Right-click into the white area and click on New Integer
7. Step Enter disk.cache.memory.capacity and hit enter
8. Step You are now supposed to enter an integer. This integer will be the amount of RAM in KB. So, enter the amount of RAM in KB that you want to dedicate to the memory cache, e.g. 131072 for 128MB RAM
For a detailed explanation of what the setting disk.cache.memory.capacity will do click here. In short, it caches website images in your RAM.