16mb or 32mb Buffer Which is Better in External Harddisk?

[Abbudin]

Hello,

I want To purchase an external harddisk , and Want To know the Difference the Between the Buffer sizes and What is actual performance difference between the same ? also Suggest some Good external Harddrives for Personal use, thanks in Advance .

[Maxforu]

Hello,
The buffer is used to hold the data before it is written to the disk or after it is read from the disk and then transfered to the main memory. Depending on how much data you are read/writing will depend on how much of a difference it will make. There has to be some memory on the disk in order to transfer the data unless it can write directly to the machine's memory.The buffers on each drive really don't interact with each other as the disks communicate to the system.Only you can determine if the $30 is worth it or not. If you are using the disk for limited storage and not constant use, then it is less likely to make a difference and therefore would be less likely to be worth it. If you are reading/writing large amounts of data constantly, then it might be worth it. The larger buffer is most likely a newer drive, which might be worth it for that.I personally would not pay extra since I would not constantly use an external drive due to cooling issues since typically the air flow is not as good. I also don't transfer lots of data, so even in the system I would not consider it worthwhile. For a server, I would consider it, especially a busy one.

[Killen]

I perfectly dont know , but I that that av increased cache on a DVR would not of that important. Cache generally stores recently accessed data in memory ( rather in main memory by the OS or in hard drive memory by the hard drive itself ) so that if the information is accessed again it can be retrieved faster.The catch is, DVRs aren't likely to need the same information again over and over. When you are recording or watching a show you are constantly moving on to the next block of data. What you are really concerned about is your overall thoroughput as reading and writing multiple data streams ( example: watch one recorded show while recording two more shows ) takes a lot of bandwidth.I suppose cache could be important for accessing guide data and other system configuration / state data however I suspect that the system is deigned to already cache that information in main memory as to lighten the load on the harddrive to allow it to be able to handle the multiple streams. Still, if the drive price difference isn't much and you don't know the exact specs needed to qualify a drive for use, I suppose it doesn't hurt too much to over engineer the solution on a one off basis. Still, when specing a drive for say thosuands of systems, it would be an expensive mistake.

[Fabian]

Hello,
theoretically you'll see an increase in speed of files in the 15-30 meg size, but other than that it Would be the same performance roughly. it'd mostly depend on the writing strategy that the drive uses, if it has NCQ, and if it's a perpendicular drive for speed increases .16 vs 32Mb buffer will make almost no difference. If the price an all other specs are the same, get 32, but I'd not worry about it too much.