question for computer gurus regarding hard drive cache

[Barad Simith]

Can anyone tell my why 8mb cache is better than 2mb? I know it must be better, but I guess what I'm getting at is this:

I'm replacing my secondary hard drive. The main drive is an 80 gig with 8 mb cache.

For the secondary, I can get another 80gb/8mb drive, or I can save $20 and get an 80 gig with only 2 mb cache.

I'm just going to use the secondary drive to mirror the saved files on my C drive in case it crashes.

So, is the extra 6 mb cache necessary? What does hard drive cache do?

I appreciate any help anyone might have.

[mwar]

1. speed

A cache is a memory buffer that can be accessed more quickly than getting the data directly to and from the drive. So on a write operation, for instance, the computer can quickly fill up the cache memory of the drive and go off to do other things, leaving the drive to do the work of writing the data from cache to the media. The bigger the cache, the more data can be buffered in this fashion. The net benefit is speeed on certain disk operations. If you are looking for increased performance spend the twenty bucks.

[Barad Simith]

4. thanks! (nt)

[benburch]

2. If it is purely a backup drive...

then the cache does not matter so much. If by "mirror", however, you mean live mirroring, then I'd buy the drive with the bigger cache. I'd also make sure that it had a high spindle speed.

You did not say how much you were spending on the drive, total, but here is a 80GB/8mb/7200 drive for $79; http://www.newegg.com/app/viewProductDesc.asp?description=22-152-018&depa=1

[Barad Simith]

3. yes, a backup drive

I guess I used 'mirror' incorrectly. When saving files, I save them to both drives, so I think of it as a 'mirror' because I do a daily properties-check on the saved folders of both drives, to make sure they're identical in size and number of files/folders.

Thanks for the link.