Hard Drive Speed

Posted on 18. Dec, 2008 by Sheli Sod in Hardware

Hard Drive Speed Matters

Computer system speed is an item of great concern to the average user. One of the most frustrating experiences on a computer is to have to wait for your program to start or to provide its results. A big piece of this is hard disk speed.

This article will discuss what can be expected from SATA hard drives which are currently the choice for performance in home and small office systems.

SATA stands for Serial Advanced Technology Attachment (SATA) which is a computer bus (smart pipeline) that has the primary function of transferring data (directly or otherwise) between the motherboard and mass storage devices (such as hard disk drives and optical drives) inside a computer.

Please see my computer speed article for information on the major factors affecting computer speed.

The question that started it all

A visitor to my computer solutions website asked the following question:

“I have a Dell XPS 410 with a Duo Core 2.4ghz processor and 4 gb RAM. I have a primary 320gb hard drive that came with the PC. I just installed a Western Digital 1tb black caviar hard drive to serve a second, separate internal drive. After getting it formatted, I transferred a bunch of data from the primary drive to this new drive as a test. I found that the transfer speed is averaging around 28 mb/sec. I was expecting a lot faster since they are both SATA drives. What speed should I expect and is this normal? Thanks!”

After consulting with some experts, I came to the following conclusion; 28mb/s for sequential writes is pretty good for a SATA drive. Memory and the processor don’t really play a role and it is purely down to spindle count/spindle speed.

Others have commented that a 7200RPM drive should have a sustained speed somewhere close to the 58MB/sec – 62 MB/sec. However, a big factor is the kind of data you are copying. The more files and folders there are, the longer it will take. The operating system overhead of creating files and directories adds time to the operation.

One 10 GB file will copy at a much faster rate than 10,240 1MB files even though it is the same amount data.

One way to speed up writes to drive would be enable the hard drive write cache. What this does is that it doesn’t immediately write to the drive but leaves the data in the hard drive’s memory until the disk gets to the spot needed anyways. This speeds up processing because putting the data into memory is much faster than actually writing it to the hard disk. However, a bug in XP has prevented this from working properly in the past. Additionally, there is a level of danger in that if power were lost due to a blackout or some other cause and the system didn’t have a power backup, the data would actually never be written. This is a low probability event but if you are really concerned about your data being right under all circumstances, you may not want to do this.

In order to enable disk write caching, you can set this up in the device manager. To check you device manager, click start->run, type in devmgmt.msc. Click on the plus sign next to disk drives and right click on the drive you want to change. Select properties -> click the policies tab and select optimize for performance and click in the Enable write caching on the disk checkbox.

Be Sociable, Share!

• 

Tags: hard drive, speed, throughput