New user's registration have been closed due to high spamming and low trafic on this forum. Please contact forum admins directly if you need an account. Thanks !
Power consumption
Power consumption
The manual says that Bubba uses less than 10 watts when active and less than 2 watts when idle. But doesn't a hard drive use more than 2 watts when idle? Or does Bubba spin down the hard drive?
My couple of minutes of research (google) suggests that a hard drive uses about 8 watts when idle and about 12 watts when seeking.
My guess is that the power usage quoted by excito (< 2watts idle, < 10 active) does not include the hard drive and maybe not even the power supply.
So my back of the envelope calculation is that the Bubba uses (10 + 12)/0.8 = 40 watts when active. Hmm...that doesn't look right.
Has anyone measured the power usage of their Bubba?
My guess is that the power usage quoted by excito (< 2watts idle, < 10 active) does not include the hard drive and maybe not even the power supply.
So my back of the envelope calculation is that the Bubba uses (10 + 12)/0.8 = 40 watts when active. Hmm...that doesn't look right.
Has anyone measured the power usage of their Bubba?
I briefly hooked up my multimeter to my Bubba when I first got it and measured the current into the back of the box. At that point it measured 13.7watts though this was only a snapshot five minutes after powering it up.
Excito can give you more information but the power supply is rated at output @12volts, 2500ma and it just gets just a little warm, certainly not drawing the full power that it could. Your comment that the HD could draw 8 watts when idle + whatever the passive motherboard takes (1-2 watts) sounds reasonable.
Excito can give you more information but the power supply is rated at output @12volts, 2500ma and it just gets just a little warm, certainly not drawing the full power that it could. Your comment that the HD could draw 8 watts when idle + whatever the passive motherboard takes (1-2 watts) sounds reasonable.
Hi all!
Your assumptions are fairly correct, just to clear out:
The 2W stated in the manual is wrong, thanks for notifying me on that, I'll remove it ASAP. That's an old figure based on the fact that we would spin down the disk when idle. However, for varous reasons (life time, noise etc., I can explain this too if anyone wants) we decided not to spin down the disk.
The disk, when operating, draws according to specs between 4W (80 GB) and 9W (750 GB), and those numbers seem correct when I measure. To this will add Bubbas own consumption, that is something just below 1W. When seeking, the disk consumption raises a little bit, totalling in around 11W, however, a "typical user mean consumption" would be around 10W, of course depending on what the user does.
Note that anything plugged in the USB host connector isn't included here, the USB specs allow for another 2,5W here. Connecing a powered USB accessory here isn't considered a normal use case, so it isn't included in the 10W, but the power supply can handle it of course.
Also, regarding the high specs on the power supply, that's mainly to handle the disks spin-up current, that can be up to 2.8A (750 GB) for a few seconds.
Your assumptions are fairly correct, just to clear out:
The 2W stated in the manual is wrong, thanks for notifying me on that, I'll remove it ASAP. That's an old figure based on the fact that we would spin down the disk when idle. However, for varous reasons (life time, noise etc., I can explain this too if anyone wants) we decided not to spin down the disk.
The disk, when operating, draws according to specs between 4W (80 GB) and 9W (750 GB), and those numbers seem correct when I measure. To this will add Bubbas own consumption, that is something just below 1W. When seeking, the disk consumption raises a little bit, totalling in around 11W, however, a "typical user mean consumption" would be around 10W, of course depending on what the user does.
Note that anything plugged in the USB host connector isn't included here, the USB specs allow for another 2,5W here. Connecing a powered USB accessory here isn't considered a normal use case, so it isn't included in the 10W, but the power supply can handle it of course.
Also, regarding the high specs on the power supply, that's mainly to handle the disks spin-up current, that can be up to 2.8A (750 GB) for a few seconds.
/Johannes (Excito co-founder a long time ago, but now I'm just Johannes)
-
PeterTuson
- Posts: 39
- Joined: 22 Apr 2007, 03:01
- Location: Great Britain
Measured power consumption
Hi All,
I have measured the power consumption of my bubba. I have a 350GB disk and have added a USB-Serial Converter to the USB port.
I have then measured the power consumption as 8W (at the plug) in idle mode. This was with no-one accessing the bubba and admin browsing the bubba.
Browsing files and moving graphiics around didn't appear to make any difference.
Can bubba be configured to use less power?
I have measured the power consumption of my bubba. I have a 350GB disk and have added a USB-Serial Converter to the USB port.
I have then measured the power consumption as 8W (at the plug) in idle mode. This was with no-one accessing the bubba and admin browsing the bubba.
Browsing files and moving graphiics around didn't appear to make any difference.
Can bubba be configured to use less power?
peter
8W sounds completely normal with your configuration. The only option to use even less power is to spin down the disk. If doing that I guess you should be down to something like 1-2 W of power.
I don't know how that is done best, but be aware that the disk may be worn out if you spin up and down the disk too much.
I don't know how that is done best, but be aware that the disk may be worn out if you spin up and down the disk too much.
/Johannes (Excito co-founder a long time ago, but now I'm just Johannes)
-
PeterTuson
- Posts: 39
- Joined: 22 Apr 2007, 03:01
- Location: Great Britain
Power Consumption when off
When I turned the bubba off, the power consumption of the power supply was 2W at the main plug.
peter