Hard drive cache memory

[Bolloxoid]

Does an 8-MB cache memory make a tangible performance difference compared to the same drive with 2 MB of cache memory, on a 7200-rpm ATA-100 drive? Is it worth the few extra bucks?

In what types of tasks there would be a difference in performance, specifically?

 

[Rys]

Does an 8-MB cache memory make a tangible performance difference compared to the same drive with 2 MB of cache memory, on a 7200-rpm ATA-100 drive? Is it worth the few extra bucks?

In what types of tasks there would be a difference in performance, specifically?

Repeated read and write from the same file, streaming ops where you can use speculative read ahead and fill the drive's buffers and cache with data ahead of a read request.

Really, the OS's in-memory disk cache size is what helps most with cache-related IO performance on disks these days. While an 8MB cache disk is almost always faster than a 2MB disk, in reality that's masked by the OS's disk cache.

And these days, 2MB disks are sometimes more expensive than 8MB disks, as the industry moves to standardise on 8MB disk caches (cheap now since you can use a single low-cost DRAM for the cache chip).

So, it's worth the miniscule extra cost, yes.

Rys

 

[Guden Oden]

8MB cache on the harddrive can make a huge difference, as seen when the first 8MB drives appeared some three years ago. Go check out the reviews and articles on www.storagereview.com if you need a detailed analysis rather than just take my word for it.

 

[tobbe]

In fact, theres a FAQ Entry on storagereview on 2MB vs 8MB buffers, succinct and informative.
I don't really need to point out that storagereviews word is the law when it comes to disks

edit: added url

 

[Bolloxoid]

All right, thanks.