IDE HDD Cache Limitations

Good Day Geeks,

Had a friend who was about to buy a hard drive (IDE) to replace a dying unit in her computer. I've linked a page full of drives:

http://www.tigerdirect.ca/applications/category/category_slc.asp?Recs=30&Nav=|c:134|&Sort=4

And mentioned she should look for one with the most cache. Now the store she went to tried to unload a drive with a 2MB cache on her, saying that IDE drives didn't get any better.

Later the manager of the store says that yes, she could use a drive with an 8MB cache, but a 16 MB cache is too much for an IDE drive.

Is there any truth to this? Are there restrictions on the amount of HDD cache that can be addressed? Perhaps it CAN be used after a firmware update?
I haven't been able to find anything to confirm the validity of this claim, and would like to be sure this store isn't lying (again).

TIA

 

I believe the store folks either don't know what they're talking about or they have a bigger profit margin on the drives with 2MB of cache, which seems unlikely.

Simple fact is, the more, the better, although the benefits to individual users probably depends somewhat on what they do with their computer. But, surely, more cache generally results in better performance, for the reasons explained is this brief article: http://www.vtec.co.uk/hard_disk_cache.asp. I don't think I'd buy a new drive with less than 8MB of cache. Anyway, most drives on the market now have 8MB or more, don't they? And, there's not much price difference between drives of equal size but with 2MB vs. 8MB of cache, from what I've see from online sources.

 

Thanks, usafveteran, but that's not really the question. I do realize that the cache is probably the biggest determining factor of a HDDs performance.

The question is: Are there any limitations to the size of the cache for an IDE drive?

The manager says an IDE drive couldn't use a 16 MB cache. I'd like to prove or disprove this notion specifically.

 

Hmm ... well ..., maybe I'm not quite getting the point. Or, rather, I see your point but it doesn't seem to make much sense. One logical question that seems to apply here is this. Why would the drive makers be making drives now with 16MB of cache - yes, IDE drives - if the drive could not not utilize it? Would you agree? I see numerous 16MB IDE hard drives from Seagate here: Internal Hard Drives (x) > Interface : IDE Ultra ATA100

 

Why are multi-core processors often marketed as running at a speed equal to the speed of the cores multiplied by the number of cores? (ex. 2.6GHz dual cores marketed at 5.2 GHz)

Why are SLI motherboards with dual PCI-e x16 slots marketed as PCI x32?

Yes, your question is logical, it's one I've asked myself, but it does not take into account the possibility that the specs are misrepresented, or misconstrued, and unfortunately, it must be put aside to answer the real question here: What are the cache size limitations of IDE hard drives?

This wouldn't be the first example of a product that's been released, with impressive specs that the end user couldn't fully utilize.

Sorry, usafveteran, you're probably right (at least enough to shut this manager up), and I appreciate your efforts here, but the original question stands.

 

Not to mention that various PC manufacturers allow you to configure a machine for 4gb of ram, but only ship a 32 bit OS. Same idea, people think more is better because they don't understand diminishing returns or limitations.

I don't have a precise answer Mada, but I did find this, which hints at diminishing returns:

http://en.wikipedia.org/wiki/Advanced_Technology_Attachment

 

This is about the best I've been able to find as well, the only limit to cache size is the point where it gets too large to search without becoming an additional overhead, time-wise.

hmmm...