OS Electrical Load
Thread Starter
OS Electrical Load
OS electrical load
Operating several laptops with internal SATA connections for multipe drives.
Typically 3-4 hardrives and 1-3 CD-DVD drives.
Add to that USB 3.0 caddies containing 2-4 more SATA hardrives
I often encounter the external hardrives giving up the ghost as being unrecognized by the OS even as brand new drives. Shuttling these around between caddies sometimes works temporarily, but the unexpected loss of the data is a PITA even if when I have backups.
Somebody has suggested that this many drives is probably overloading the voltage on my machines and that most of these drives should be disconnected untill I actually need to copy their data to or from.
Obviously disconneting drives in itself is an added burden but if this is the only way out I will adjust.
Any thoughts to this theory of overload and the need to disconnect ?
Operating several laptops with internal SATA connections for multipe drives.
Typically 3-4 hardrives and 1-3 CD-DVD drives.
Add to that USB 3.0 caddies containing 2-4 more SATA hardrives
I often encounter the external hardrives giving up the ghost as being unrecognized by the OS even as brand new drives. Shuttling these around between caddies sometimes works temporarily, but the unexpected loss of the data is a PITA even if when I have backups.
Somebody has suggested that this many drives is probably overloading the voltage on my machines and that most of these drives should be disconnected untill I actually need to copy their data to or from.
Obviously disconneting drives in itself is an added burden but if this is the only way out I will adjust.
Any thoughts to this theory of overload and the need to disconnect ?
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lomapaseo,
If you're talking about USB devices, then yes, its a well known fact that the motherboard produces a finite amount of current on the USB ports (the exact amount varies by manufacturer). It is also a well known fact that on some motherboards some ports are high draw and others are low draw, and if you happen to plug a high draw device into a low draw port, you won't see much.
If an optional external power adapter is available for your caddies, try that. Otherwise a powered USB hub. Quite honestly if your caddies are for 2+ drives and you've got drives in all the slots, you would be better off with external power adapters anyway.
If you're talking about USB devices, then yes, its a well known fact that the motherboard produces a finite amount of current on the USB ports (the exact amount varies by manufacturer). It is also a well known fact that on some motherboards some ports are high draw and others are low draw, and if you happen to plug a high draw device into a low draw port, you won't see much.
If an optional external power adapter is available for your caddies, try that. Otherwise a powered USB hub. Quite honestly if your caddies are for 2+ drives and you've got drives in all the slots, you would be better off with external power adapters anyway.
Spoon PPRuNerist & Mad Inistrator
Operating several laptops with internal SATA connections for multipe drives. Typically 3-4 hardrives and 1-3 CD-DVD drives.
SD
Thread Starter
Laptops with 3-4 internal HDDs and 1-3 CD drives? We call those desktops in this part of the world!
Mizture
If you're talking about USB devices, then yes, its a well known fact that the motherboard produces a finite amount of current on the USB ports (the exact amount varies by manufacturer). It is also a well known fact that on some motherboards some ports are high draw and others are low draw, and if you happen to plug a high draw device into a low draw port, you won't see much.
If an optional external power adapter is available for your caddies, try that. Otherwise a powered USB hub. Quite honestly if your caddies are for 2+ drives and you've got drives in all the slots, you would be better off with external power adapters anyway.
If an optional external power adapter is available for your caddies, try that. Otherwise a powered USB hub. Quite honestly if your caddies are for 2+ drives and you've got drives in all the slots, you would be better off with external power adapters anyway.
I assume that is 5 volts or so and that by the time it runs several feet to the caddies it may have dropped.
Spoon PPRuNerist & Mad Inistrator
Are these USB slots all on-board, or are some of them on a dedicated expansion card?
You could try a quick test by connecting multiple USB flash drives in place of the HDDs to see if it's an overloaded USB controller, bus or USB-PCI bridge. At least then you would eliminate the physical HDD power draw from the situation.
SD
You could try a quick test by connecting multiple USB flash drives in place of the HDDs to see if it's an overloaded USB controller, bus or USB-PCI bridge. At least then you would eliminate the physical HDD power draw from the situation.
SD
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If once-upon-a-time all this was working my first question would be what changed?
Could be a flakey power supply powering the caddy, could be a worn out or damaged usb connector. Could even be the laptop being configured into battery save mode and disconnecting idle disks.
Could be a flakey power supply powering the caddy, could be a worn out or damaged usb connector. Could even be the laptop being configured into battery save mode and disconnecting idle disks.
Thread Starter
Are these USB slots all on-board, or are some of them on a dedicated expansion card?
do they make desktop keyboards for fat fingers ?
come to think of it what would a QUERTY keyboard look like for dyslexics
Spoon PPRuNerist & Mad Inistrator
I have read recommendations for USB 2.0 of no more than one HDD per USB controller. With the bandwidth of USB 3 being greater that is probably not so much of a problem - although the speed of HDDs is increasing (but not as fast).
SD
SD
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One thing that's possibly worth checking is the internal power supply - that sounds like a lot of disks, and it's possible that if you're near your limit, then when your USB controller is working quite hard then it's overloading that limit.
You can see lots of strange things when near the power limits - I've seen graphics glitches, sound clipping etc.
This checker will give you a value, though is quite hard to use. What rating (in watts) is your current power supply in the desktop?
You can see lots of strange things when near the power limits - I've seen graphics glitches, sound clipping etc.
This checker will give you a value, though is quite hard to use. What rating (in watts) is your current power supply in the desktop?
Thread Starter
I checked "Belarc" for the computer but couldn't find a listing for the Power Supply. The only visible tag on the power supply is DP/N OM1J3H.
What I have a question about is what part of a USB circuit draws significant wattage. Each of the HD caddies has it's own power supply which I assume handles the spin part of the drive but not the bits and bytes. If the wattage drawn by the PC board and caddy circuits is small (compared to the power supply wattage) then the problem might be in the USB path and voltage drops along the way rather than wattage
At this point I have disconnected the caddies and intend to use them only when I update backups to them. I also shortened up the USB cables from 6 ft to 3 ft. I'm using the 3 internal HD drives for daily work.
What I have a question about is what part of a USB circuit draws significant wattage. Each of the HD caddies has it's own power supply which I assume handles the spin part of the drive but not the bits and bytes. If the wattage drawn by the PC board and caddy circuits is small (compared to the power supply wattage) then the problem might be in the USB path and voltage drops along the way rather than wattage
At this point I have disconnected the caddies and intend to use them only when I update backups to them. I also shortened up the USB cables from 6 ft to 3 ft. I'm using the 3 internal HD drives for daily work.
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I checked "Belarc" for the computer but couldn't find a listing for the Power Supply. The only visible tag on the power supply is DP/N OM1J3H.
- It's common practice to put the minimum rated power supply in with the case - running a large number of drives is likely to be really pushing the design of it.
What I have a question about is what part of a USB circuit draws significant wattage. Each of the HD caddies has it's own power supply which I assume handles the spin part of the drive but not the bits and bytes. If the wattage drawn by the PC board and caddy circuits is small (compared to the power supply wattage) then the problem might be in the USB path and voltage drops along the way rather than wattage
At this point I have disconnected the caddies and intend to use them only when I update backups to them. I also shortened up the USB cables from 6 ft to 3 ft. I'm using the 3 internal HD drives for daily work.
At this point I have disconnected the caddies and intend to use them only when I update backups to them. I also shortened up the USB cables from 6 ft to 3 ft. I'm using the 3 internal HD drives for daily work.
What could (in theory) be happening is that as your main PSU is being pushed out of limits, and it's not a top-quality one, your 5v rail may be struggling - this would cause problems for USB. Short of getting a PSU tester (though they're about $10 from your local favourite computer supply store), you could try plugging in a USB mouse and seeing if the light on the bottom shines consistently.
Generally though, getting a nice big PSU is something you could look at - it'll actually draw less power than a lower rated one at the same output. Either that, or it's multimeter time and working out exactly what's being drawn.
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1) he says he's using laptops, so the internal power circuitry is fixed: changing the external power brick will make little difference
2) I've yet to see a laptop with three internal drive connectors - quite simply there isn't room for three internal drives
3) several mentions of an "expansion card" - which makes little sense in the context of laptops. Is this a USB > SATA adaptor? A cardbus/PCMCIA > USB adaptor? An external USB hub?
4) Is the laptop USB2 or USB3? If the laptop is USB2, having a USB3 external hub will not speed things
5) as has already been asked, has the power saving features on the USB root hubs been disabled in the device manager?
6) If you have USB3 caddies plugged into USB2 sockets you may not be able to draw enough current to spin the drives. Remember USB2 caddies required the use of TWO USB sockets to achieve connectivity
it would help if we knew the make/model of all the hardware involved
2) I've yet to see a laptop with three internal drive connectors - quite simply there isn't room for three internal drives
3) several mentions of an "expansion card" - which makes little sense in the context of laptops. Is this a USB > SATA adaptor? A cardbus/PCMCIA > USB adaptor? An external USB hub?
4) Is the laptop USB2 or USB3? If the laptop is USB2, having a USB3 external hub will not speed things
5) as has already been asked, has the power saving features on the USB root hubs been disabled in the device manager?
6) If you have USB3 caddies plugged into USB2 sockets you may not be able to draw enough current to spin the drives. Remember USB2 caddies required the use of TWO USB sockets to achieve connectivity
it would help if we knew the make/model of all the hardware involved
