HDD performance spikes

I have a Dell Precision T1700 I purchased for about $1500 almost a year ago. I am having some moderate hard drive issues. I think it's not as fast as it should be. Booting seems quite long considering how many things are running at startup.

There are two 1TB drives, both ST1000DM003-1CH162's. I am running Windows 7 Pro 64-bit and the system has a Xeon E3-1245 CPU with 8GB of RAM. I am positive that the drives are defragmented and I'm pretty sure there is no spyware or unwanted demanding programs auto-starting during boot. I cannot determine if it's a problem with the drives, drivers or other system-related stuff.

I tried running HD Tune to check the HDD performance. The results for both drives are quite different. The system drive, on the left, has very unstable performance unlike the data drive which appears to performs well. Any ideas?

Solution 1:

This is completely normal to see such spikes on traditional (spinning) system drives.

HD Tune's benchmark is designed to scan the drive outside-in (from beginning to end) so that it can draw the graph left-to-right. With this kind of scanning the header doesn't have to do long jumps and reliably measuring read/write speeds is possible.

On your data drive it works perfectly, but on the system drive OS tries to read/write in other areas of HDD while you're running the benchmark. HDD needs to reposition header, do what OS requests and then return to benchmark's track, causing the spikes.

Run the benchmark from a live media (eg. Hiren's Boot CD) and there will be no spikes. SSDs show no spikes too, because they have no moving parts, thus no "penalty" for reading non-sequentially.