pardon my ignorance...explain HD cache

[smirkus]

I am just curious if a larger HD cache means better performance, or is just a necessary part to larger HDs. For example, I know that the western 160gb HD has an 8mb cache, while the 250gb has a 16mb. Does the larger cache just make it functional, since data will need to be collected from a larger hard drive, meaning a larger cache would make up for a longer search...or something like that.

The reasons I ask this are just that why not sell a 40gb HD with a 32mb cache, because then it would work better? So basically, will a 160gbHD work better worse than or equal to a 250gb HD with a 16mb cache?

Thanks, and pardon my newbie-ness.

 

[fishmahn]

A drive would function just fine with 0 cache although a little slower (actually, I think it would still have some cache - but it would be called a track buffer or something like that).

Overall there is almost no performance difference between a 8mb cache and a 16mb cache drive (all other things identical). Where you do find a performance difference is when you get lucky and the piece of data you want is on the cache. A larger cache means you have a better chance of being lucky.

Mike.

 

[p05esto]

Those are interesting questions and I'd be curious to know the answer to as well. Specifically, if a larger cache is related to the size of the drive in any way. My guess is no but....

 

[sturm]

The cache works alot like cpu cache, recently used data is stored there incase its needed again soon.
Cache can also be used to store data until it can be written to the drive.

 

[RichPLS]

Exactly... Larger cache enable drive to work more efficiently under certain circumstances. For large continuous file transfer, virtually no benefit.