What's the difference between 8 MB and 16 MB Cache on a hard drive?

Question

I'm looking to replace a dead hard drive in an older notebook. The current (bad) hard drive is a Toshiba 60 GB 5400 RPM HDD with 16 MB cache. It's very difficult to find replacement ATA-100 notebook drives with 16 MB cache. Do I even need this extra cache? Is twice the cache noticeable?

Solution 1

Tom's Hardware has a pretty good collection of harddrive benchmarks, pick your drives and see for yourself.

p.s. i remember reading somewhere that you won't notice any difference between 8 and 16 Mb cache in normal HDD use.

Here's the article i was talking about.

p.p.s: i found the benchmark that fits your case - draw your own conclusions.

Solution 2

The cache is RAM that's used as a buffer to hold read and write information for the CPU to process. It is definitely noticeable. The larger the buffer, the more information can be held for processing. Assuming your CPU can keep up with it all (more than likely) you will notice it.

Solution 3

The difference in speed is more noticeable for external hard disks. But for an internal hard disk, because the operating system's disk cache is much larger than 16MB and its strategy for handling operations on the disk is different, the speed difference should be somewhat less noticeable.

Please note the emphasis on "less noticeable", because the difference in speed is still there. But to you as a user it's less important if the disk is a bit slower, since the computer is still available even if the disk keeps on turning in the background.

Comments

[Sasha Chedygov]

Yes, it's definitely noticeable, but I don't know enough about it to give an answer.

[Richard]

i've updated my answer, see this article: tomshardware.com/reviews/…

[Nathan DeWitt]

looks like everything is SATA. not sure where to find older IDE info. and i'm sure you meant 16 instead of 19, right?

[John T]

If you take a look at the benchmarks pointed out by the accepted answer, you can see that the top 10 or so drives are all 32mb and 16mb cache. Most of the bottom ones are 2mb and 8mb cache. Although the cache isn't the only deciding factor I agree with you there, you also need to choose a reputable drive with low seek times (and higher rpm if desired). Hence the drives which stand out from the correlation in the benchmark (I saw one 8mb drive near the top of the list).