The 8MB cache is more, right? Actually, it's 4x as much as the 2MB cache, right?
Cache is kind of like a 'lookup' holder - by this, I mean that it reads data from the hard drive, stores it in the cache
and then sends it out. The thing about cache is that it's sort of like a reverse on prefetch (which is more or less a prediction/prototype for already used executables). Now, this still brings up the question of which is better/faster and why. I'll save some of you the trouble of reading this entire post and spill it right now: an 8MB cache is better on a hard drive than a 2MB cache. As to why, keep reading
So, cache stores data; we know this, but so does a hard drive. The cache, however, is similar to RAM, in that it's temporary memory that can be accessed quickly (more quickly than the normal
way). Now then, just think if you had no cache on the hard drive: the drive would have to read one bit, send it to the motherboard, read another bit, send it to the motherboard, and so on. This would even make opening a simple text file take much longer than we're used to. Since cache stores the data (a buffer in other words) before it sends the data off, the hard drive can read/write to its heart's content until the cache/buffer is empty. The cache (once again, the buffer) accepts both input and output, so when the computer needs to write something to the hard drive, it sends it to the cache and the hard drive writes what is on the cache. If you didn't have this cache, guess what the process would be: motherboard sends a queue to the hard drive, the hard drive send request for data to the motherboard, the motherboard sends a bit, the hard drive writes the bit, the hard drive sends a request again, the motherboard sends another bit, and so on. All those requests and writing breaks would cause some serious load/save time.
Eh, in short, more cache, more better (excluding 500MB+ for web browser cache
). Yet another long, long post that could have been shortened to less than 10 words