Rather than being a set figure, the default cache size is set as a percentage of your total hard disk space. This figure has become outdated because affordable disk sizes have increased rapidly in recent years. Internet Explorer 7 will automatically reduce the cache size to 1024MB (that is, 1GB) if it is larger than that figure, but this is still far too high for most users. If there is too much data stored in the cache, Internet Explorer can start running very slowly or unreliably.