Older SM MB, H8DME-2 with SMBus connection ...

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moxford

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Apr 24, 2017
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K D

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Dec 24, 2016
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CBLCDAT0601 is what I ordered for an 846-SAS2 backplane in my JBOD .
 

moxford

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Apr 24, 2017
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Great, thank you!

Does your BP have multiple connectors, or just the one? The 846TQ has multiple SMBus connectors so I'm trying to figure out if I need one cable or multiples to wire them all up.

Thanks again!

-mox
 

K D

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Dec 24, 2016
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The SAS2 backplane has only one i2c connection. The TQ has multiple. I remember reading somewhere that you need an i2c multiplexer for that. I've seen a LSI Logic I2C Multiplexer accessory kit but don't know if that will work for this case.

The way I understand you need the i2c to connect the backplane to the motherboard so that he motherboard can read temp and other information and control the backplane fans as well.

I didn't need it for my TQ case as the individual ports are connected to the HBA with breakout cables with spgio and the he fans are connected directly to the motherboard which is not the situation with my JBOD which uses a SAS2 backplane.
 

moxford

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Yep yep, you are totally correct.

Unfortunately the fans on the motherboard are all 3pin, and I want to script up some dynamic RPM control through the I2C/SMBus interfaces based on drive/CPU temps, so I need to do a little custom work ... if I could find the darn header/connector type!

Thank you so much for the links and help!

-mox
 

vl1969

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Feb 5, 2014
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I don't get it.
it looks like I have the same setup and I do not connect fans to the backplane. they all connect to MB
I don't think I even have anything connected to the backplane except power and sata connectors.
and all is working fine. why do you need this connector?
curious mind want to know
 

i386

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Mar 18, 2016
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@moxford
I think you need to connect just one cable from the backplane to the mainboard, one of the mods here knows more about it.

@vl1969
The idea is that you get information (like drive temperatures, fan speed) from the backplane and control the midwall fans in ipmi.
 

vl1969

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Feb 5, 2014
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@moxford
I think you need to connect just one cable from the backplane to the mainboard, one of the mods here knows more about it.

@vl1969
The idea is that you get information (like drive temperatures, fan speed) from the backplane and control the midwall fans in ipmi.
I can understand the drive temps, but I do not see the drives in IPMI anyway so not sure how that works, but since fans are connected to MB directly, shouldn't you see the fan speed in IPMI anyway? I know I do
and since all fans are 3 pins not 4 they are either on or off right?
I get the drive temps via smartmon tools and fans are controlled based on overall chassis temp.

could be a moot point with me as my box is heavily modded outside of normal config.
I removed the oem PSU and fans,
my box is running on standard ATX 760W PSU
I took out the fan wall and replace it with 3x140mm quite fans zipped tied together.
replaced the back wall fans with same size but quite models
and CPU have the CollerMaster T2 or 212, can't remember now, vertical heat sinks with 120mm fans on
them had to change the coolers on CPU twice as while they look almost identical one model is just a bit higher than the other about 1/8 of an inch, so don't fit.
 

moxford

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Apr 24, 2017
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With 3-pin fans, they're either on or off and while you can see the speed (RPM) you cannot quiet them down.

By going through the SMBus/I2C bus and plugging the fans into the backplane, I should be able to control the speed through software.

As the drives get warmer I can spin the fans up more, giving more airflow but more noise. When the drives/CPU are already cool, the backplane fans can spin down and be quiet.

I have replaced my fan-wall as well (3x120 since I still have the stock format PSUs). Normal 120/140mm fans don't usually have enough pressure (lots of CFM, but not as much pressure) to suck the cool air in over the drives so I have iPPC fans in there. Not as quiet, but better than stock and still have very good pressure.

Being able to spin down the midplane (as well as the rear fans) based on a combination of drive, CPU, and environmental (SATA cards, NB/SB) means I can get to a relatively quiet box until it's loaded, and then it becomes louder based on load.

I'll probably put a thermal watchdog cutoff as well, in case the OS gets wedged.

-mox
 

vl1969

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Feb 5, 2014
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well my setup is in the bassment, stock PSU was too loud.
I still have the guts and PSUs :)
maybe put it for sale on this board.
 

moxford

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Apr 24, 2017
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Ah! Found it!

Intelligent Platform Management Bus Description and Pinout

The 846TQ and SM H8DME-2 SMBus are HDR1x4 IPMB TypeB Molex SPOX #22-44-7041 !

Shrouding and pinouts match ... happy day!

Now to (try and) source the obsolete components and start building. Since the bus will handle 127 addresses I should be able to just put them all in parallel without having to use a 3Ware multiplexer card or anything else.

-mox
 
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moxford

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Heh, having zero luck finding the wire-part (Molex #22-43-3040) ... no one seems to have any lying around. =(
 

Terry Kennedy

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Heh, having zero luck finding the wire-part (Molex #22-43-3040) ... no one seems to have any lying around. =(
That is an insulation displacement (ribbon cable) connector and you're likely to have problems unless you have the appropriate tooling. As you discovered, it is also obsolete.

I think what you want is connector housing 50-37-5043 and crimp pin 08-70-1040. Both are in stock at Mouser, Digi-key and Newark.



 
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