Re: Hard drive activity LEDs
I suspect the activity LED is derived from the hard drive controller - rather than the drive itself. (Hard drives used to have activity lights on board, but IIRC, that was in the days bfore Integrated Drive Electronics (IDE).
Re: Hard drive activity LEDs
Thanks for the reply peterb I'd nearly forgotten about this.
On IDE drives 2 of the wires actually control the led signal, (pins 2&3 if I remember correctly) if you strip them from the ribbon cable you can then directly wire in an LED and it will work.
I found a guide to do that some place.
However I've found no info on sata drives and if two of the pins can be used to pull the signal from or how to pull the signal from them :(
I'm sure it can be done is some way, I've seen it on drive caddies, one of the servers at work uses standard sata drives and each caddy has an activity light on it.
Although that could be feed from something on the hotswap PCB.
Maybe a controller chip on the PCB that's just pulling the acvitivity data for each drive? as each drive has a sata cable that likns back to the main sata controller card from the hotswap PCB.
I've also seen some 5.25" bay cadies like that.
I've sort of given up as I just cannot find any info on this. :(
However at the same time the modding of my main case, that this idea was for, has sort of ground to a halt as I just don't know what to do with it atm and I don't have the money to put into it atm. :(
EDIT: correction, it's pin 39
Here's the mod for multiple IDE hard drive activity LED's http://forums.bit-tech.net/showthread.php?t=23567
If it is just fed directly off the controller chip then why don't motherboard manufactures put multiple HDD led pins on their motherboards :(
EDIT2: just been doing some reading up on the SATA specs, it seems pin11 on the power connector can be used for stagered spin up or activity signal, just no idea how to use it.
Also the normal way sata activity is read is via the controller, on many sata controller cards you have a pair of pins for a combined activity signal and a pair of pins for each individual connector.
Same thing on sata multipliers (a thing like a usb hub but for sata, lets you pulg up to 5 sata drives into one port)
However these things are far to expensive for me to afford :(
Re: Hard drive activity LEDs
Quote:
Originally Posted by
Pob255
<---snip
I'm sure it can be done is some way, I've seen it on drive caddies, one of the servers at work uses standard sata drives and each caddy has an activity light on it.
Although that could be feed from something on the hotswap PCB.
Maybe a controller chip on the PCB that's just pulling the acvitivity data for each drive? as each drive has a sata cable that likns back to the main sata controller card from the hotswap PCB.
I've also seen some 5.25" bay cadies like that. snip--->
Yes, I've seen that on dual Esata/USB caddies, but my assumption (always dangerous :) ) was that it came from the USB controller when used as a USB caddy, and was just a power light as Esata (not used one as an Esata enclosure very much)
Quote:
Originally Posted by
Pob255
EDIT: <---snip
EDIT2: just been doing some reading up on the SATA specs, it seems pin11 on the power connector can be used for stagered spin up or activity signal, just no idea how to use it.
Also the normal way sata activity is read is via the controller, on many sata controller cards you have a pair of pins for a combined activity signal and a pair of pins for each individual connector.
Same thing on sata multipliers (a thing like a usb hub but for sata, lets you pulg up to 5 sata drives into one port)
However these things are far to expensive for me to afford :(
You were more thorough in your research than I was :embarrassed: But that is interesting. I had noted the various connectors on the SATA power lead, but not really (or not at all !) looked into the details - I had thought that the drive was completely controlled through the SATA interface.
There is a little info here:
http://arstechnica.com/civis/viewtopic.php?f=7&t=124624
and here
http://forums.techpowerup.com/showthread.php?p=730924
although they are old and imply that not all drives support t, and that some drives use it for staggered spin up and others use it for activity.
So I suppose the next step would be to look at teh drive specs and then do a bit of work with a 'scope (or an old drive :) ) and see what happens - modifying a power lead (providing pin 11 is internally connected in the external power connector) The articles I referred to sugest that the output is open collector so shouldn't need anything more than an LED (and possibly a current limiting resistor)
Scope for some experimentation!
Re: Hard drive activity LEDs
I'm looking for the same information for my homemade NAS with 10 sata2 drives.
After digging around and findiing the same information about the pin 11 on the power cable; Google, lovely Google; came up with the answer at page rank 8. :shocked2:
cooldrives.com / index.php / sata15p-act-2p . html
Sorry for the cryptic link above. 1st post won't allow url's. :O_o1:
Looks like CoolGear came up with a semi-elegant solution in the form of an adapter cable for the power line. And at $3.99 per, I just might splurge for 10 of them myself.
Randy
Re: Hard drive activity LEDs
interesting however
Quote:
Please verify your drives' functionality before utilizing this cable. We are not aware of any specific model drives that do not work in this manor, however this behavior is not required by SATA specification, and some drives may in fact not support activity on PIN11 at all.
on top of that being a molex to sata adapter you lose 3.3v which some green/eco drives use, so not only would the led not work there's a chance of certain drives not working as well.
On top of that
Quote:
We do not ship outside the US. NO INTERNATIONAL ORDERS. NO CANADIAN ORDERS. NO EUROPEAN ORDERS. NO SOUTH AMERICAN ORDERS.
So no use to us.
Granted if I could find on in the UK I'd pick one up to see what it's like.
However I'd much rather it be a sata to sata+monitor wires, many new psu's have more sata connectors than molex these days.
