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Hard Drives Evaluated for Noise, Heat and Performance
Sander Sassen writes "Ever wondered what harddisks offer the best combination of performance and low noise? Hardware Analysis evaluates all recent 5400 and 7200-rpm harddisks and focuses on noise, heat production and overall performance. Their results show that 7200-rpm spindle speed is no guarantee for high-performance and that low-noise and high-performance is not an impossible combination with some harddisks."
It's about damned time. We have more than enough reviews on speed and performance, but there is a serious dearth of information on noise.
If you follow discussions at other forums for ReplayTV and TiVo owners, you already know that in that situation you don't really care about performance. A 5400rpm drive can easily handle the job. However, noise is critical, and hence, some of these systems don't have fans, making heat also critical--if you upgrade with a drive that runs hotter than the original, you're likely to have random failures.
So this sort of review is wonderful, both for the information it provides, and for encouraging manufacturers to pay attention to these factors so that they will look good in the future.
One thing that could be improved on many of these quantitative reviews is if they quit relying upon surface temperature probes (which is HORRIBLY unreliable. A slightly grainy texture would make the drive appear much cooler because of reduced heat transfer), and instead go right to the source: Power consumption. Is it so hard to measure the current on the 5 and 12V inputs, and deriving an actual power consumption metric for the drive? Not only is this valuable as it absolutely directly relates to heat, but it additionally is useful for those building low power rigs.
Anyways, just a thought.
Why not develop a speedy drive that can slow itself down if it starts to generate too much heat or if it's not being used (as opposed to shutting it completely off)? I assume it's probably much easier to create a single speed motor than a variable speed one, but what would the disadvantages be?
The heads in your hard drive fly above the surface of the media due to the circulating air inside of the harddrive. Typically the heads are also engineered to fly at a specified height at all times given a specified amount of air moving through the drive. If you slowed the drive down the head would most likely fly lower or not fly at all, this would be quite bad for your data and the head.
Hard drive spindle motors are variable speed and are typically servo controlled for speed. Adjusting the speed wouldn't be a big deal except for the above.
Honestly - I do not feel the need of anything faster than the slowest 5400 RPM HDD for now - my PC has gobloads of RAM and I can make use 128MB-per-HDD as buffer. Easily.
What worries me is, the faster you spin, the more catastrophic a failure is.
What I DO care about, is reliability and shock resistance. If anyone sells a reliable HDD that would survive 5-inch drop and still operate with all my data intact, I'll buy it in a heartbeat.
Compared to my data, the HDD and the theoretical time that can be saved with higher speed worth REALLY little. Almost nothing.
The CPU will still be interrupted by disk I/O IRQ's unless you use SCSI. Lots of discrete disk accesses means lots of interrupting, which is why SCSI is used nearly exclusively in server environments.
"Gold still represents the ultimate form of payment in the world." - Alan Greenspan, 1999
Forgive me if I'm missing the point, but I can't see that choosing a hard disk on its noise production is in any way sensible.
Noise is damned important in many applications. TiVo, for instance, needs lots of capacity, but speed is not a critical issue. Any modern 5,400RPM drive is more than sufficient. Who wants to watch a movie and listen to a loud whine from a disc drive? Also, since TiVos tend to live in "entertainment centers" and have limited cooling, heat is a big concern.
Another good example is my firewall machine. It runs my mail server, FTP server, and web server. It performs NAT for my network. The a-number-1 thing that I want from that machine (outside of reliability) is quiet. None of the applications on that machine get much action. My web server is a private page that lets me look at my system temperatures and voltages -- so it does not generate a lot of hits. The mail server serves me and a few freinds. But the machine is in my office running 24/7. I don't want to hear a loud hard drive, nor do I want to put six fans in the case to extract heat. So I run a slow, low wattage Duron (650mhz) and a 20GB, 5,400RPM hard drive.
It's all additive. The machine on which I work is loud enough because of my "need-for-speed." It's got multiple fans, hard drives, etc. And it sounds like it. The quieter I can make the other machines, the better off I will be.