Seagate FreeAgent Go 1TB and 640GB portable USB drives
Posted: Wed Jul 14, 2010 11:21 am
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There are so many ways that "dB" is used that w/o the actual Wikipedia reference, I can't answer. However, I can say that there's a difference in SPL -- the total sound pressure at a specific distance -- vs the peak in a spectrum. The curve never actually reaches 0 dBA at any frequency, but the overall SPL is still 12.3 dBA/1m: SPL is the "sum" of all the pressure at every frequency.wouterr5 wrote:One question on the measurements: Wikipedia says that to be able to hear tones at 2 Khz or lower, they must be above 0 dB. However, this harddrive is probably still hearable from 1 meter in a quiet room at night, while according to SPCR's measurements it never crosses 0 dB below 2 Khz... So, is Wikipedia wrong or is there something i missed
The first option is probably better than the second because it tackles both airborne and vibration noise. WD1200BEVS is a 120gb model, which suggests it's a bit older, maybe? If so, a newer drive might be quieter. Hard to say.david_f1976 wrote:Interesting. I've recently bought a completely fanless pc with the aim of putting it in the living room. Just playing about with it at the moment and so have a 2.5" internal hard drive installed (Western Digitial 1200 BEVS from memory) but the noise from it is distracting when nothing else is happening in the room, e.g. I'm reading. Just mulling over options in my head but any ideas on how the noise from these Seagates would compare with putting the existing hard drive in a Scythe hard drive enclosure mounted in a rubber-grommet bay or elastically suspending my current drive?
w/HD Tune Pro on Win7-Intel SSD system via SATA: Avg. read - 67mb/s, random access - 21msjstyles wrote:I would be interested in how fast the bare drive is outside of the usb case. Can you test the speed of the 1tb drive direclty connect to sata or e-sata?
Thanks
Thanks againMikeC wrote:w/HD Tune Pro on Win7-Intel SSD system via SATA: Avg. read - 67mb/s, random access - 21msjstyles wrote:I would be interested in how fast the bare drive is outside of the usb case. Can you test the speed of the 1tb drive direclty connect to sata or e-sata?
Thanks
That's pretty neat! Would never have even thought to look for them. I have the enclosure now though
I think the reason the 12.5mm thick 2.5" drives are not available bare is because the demand for them would be extremely low. They don't fit in any notebooks. The 640gb 9.5mm thick Momentus is available, but it's not the biggest capacity bare 2.5" model Seagate offers right now. Oddly, the biggest is a 750gb 7200rpm model.bozar wrote:I wish the drive without the chassis where available for purchase.
Seagate's Scorpio 2.5" notebook drives are much quieter than the 3.5" models, but they aren't exceptional
Simply not true, as reported. That's close to what they draw in idle, and in seek it doubles. I actually tried it on 3 different systems; the notebook had the lowest power draw. Besides, measuring and reporting power consumption is standard on every review we do.Monkeh16 wrote:I'm not sure why you're bothering to try and give power consumption figures for these drives. It's not possible for them to use more than 2.5W.
USB 2.0 is limited to 500mA @ 5V. The drive would be unable to draw more from a single port on most systems (some are not strict about it). The AC consumption is a widely inaccurate measure, especially under I/O load.MikeC wrote:Simply not true, as reported. That's close to what they draw in idle, and in seek it doubles. I actually tried it on 3 different systems; the notebook had the lowest power draw. Besides, measuring and reporting power consumption is standard on every review we do.Monkeh16 wrote:I'm not sure why you're bothering to try and give power consumption figures for these drives. It's not possible for them to use more than 2.5W.
We know from testing many 2.5" drives in the past that they typically idle at 1W or less, and peak at about 2.5W during write/read operation. A reading of the USB 2.0 and 3.0 Specifications indicates that maximum rated current for each port is 500mA and 900mA, respectively, at 5V. This translates to 2.5W per USB 2.0 port. The current is supplied by the 5V standby line in a PC, usually rated for at least 2.5A. However, the specs appear to be recommended ratings for external USB devices. The Intel ATX12V Power Supply Design guide v2.2 mentions, for example, that on wakeup, an external USB device may cause a "peak currents as high as 3.5A lasting no more than 3 seconds", referring probably to spin-up of an external hard drive. It's not clear whether there is current limiting in the port circuitry; non-compliant devices might be able to draw more than 2.5W, with potential higher than normal long-term stress on the USB circuitry in the PC.
In the recent past, some external 2.5" drives were supplied with a USB cable that had two plugs on the PC side to ensure enough current could be drawn safely. As you know from photos above, the cables for these FreeAgent Go drives have just one port per end. Still, the drive in our FreeAgent Go 1TB is rated for 0.75A at +5V or 3.75W, probably the maximum at spin-up. (See the last page for photos and details.)
It's not easy to test the power draw through a USB connection. About the best we could come up with was to monitor the power draw of a laptop while running these USB 2.0 external drives from it. The battery from the notebook was removed altogether to prevent any extra power going to charge the battery.
The result aren't exactly definitive, but it appears that the 640GB and 1TB draw about the same power from the USB line when idle. The 2.6~2.7W AC additional at idle seems inordinately high given that the drives actually pull no more than 1W DC, even if you includes the power lost through the AC/DC conversion of the laptop. During read/write, the power jumps to around 5~6W AC maximum, which again seems too high. In any case, running these (or any) USB-powered drives off a laptop will have some impact on overall run time on battery; many low power laptops draw just 10~15W AC in normal use, so even the minimal additional load of a USB drive in idle could result in a 10~20% reduction in untethered run time.
Good points... and a good idea re- USB cable power monitor. I made a shunt resistor cable-break to monitor the power of SATA and ATA drives, so this should be no problem. Still have a 0.01 ohm resistor or two. Next time I break out the soldering iron and want another project to tackle...Monkeh16 wrote:Some root hubs have current limiting circuitry, some don't, hence my comment on less strict systems.
You may want to note that most laptops will entirely disable the root hub unless a device is connected, and that USB has very high (relative) CPU load, which easily pushes up the AC power consumption.
You could fairly easily make a cable to check USB power consumption: Cut the insulation open, break the +5V line, and patch it through a reasonably accurate ammeter (a good quality multimeter would do the trick). Be aware of the risk of data corruption, however.
Strange... amazing no one commented before. Corrected, btw, w/ this file:wouterr5 wrote:Eum, Mike - on the last page, there is a link to the sound of the 640 GB version, but the link points to:
http://www.silentpcreview.com/files/sou ... d18dba.mp3
The sound sample doesn't sound like a hard drive indeed