monitor +/-12V supply current of any pci or pci express slot

[sm625]

Is there any way to measure the +/-12V supply current of a card in a pci or pci express slot. Is there a sensor that I can read? Even if I could only read the power supply common to all slots, even that would be ok I guess.

 

[mfenn]

You can measure the +12V rail of the PSU very easily of course.

If you want to test the actual PCIe slot, take a gander at the pinout. The first 3 pins on the bottom of the connector are +12V. Get a thin solid core wire, strip one end, and hammer it flat. Cut a piece of stiff plastic to size. Then tape the wire to your plastic card in the right position and hook the other end to your meter. Insert into a free PCIe slot.

 

[aigomorla]

if ur thinking of doing what mfenn states please attempt on a Riser ... that way u can leave your motherboard immaculate from tampering.

they look like this.. can be found cheap on ebay and amazon.

 

[mfenn]

if ur thinking of doing what mfenn states please attempt on a Riser ... that way u can leave your motherboard immaculate from tampering.

they look like this.. can be found cheap on ebay and amazon.

I wasn't saying to change the motherboard, but instead to fake up a "PCIe card" with monitoring of the appropriate pins.

 

[aigomorla]

I wasn't saying to change the motherboard, but instead to fake up a "PCIe card" with monitoring of the appropriate pins.

oh cuz i thought u were telling him to shove a flattened wire inside the socket with the card... and i was worried when pulling the card out, it could snag a pci-e pin and pull it out...

if thats not what u meant.. then yeah.. ignore my riser recommendation.

 

[PottedMeat]

You can measure the +12V rail of the PSU very easily of course.

If you want to test the actual PCIe slot, take a gander at the pinout. The first 3 pins on the bottom of the connector are +12V. Get a thin solid core wire, strip one end, and hammer it flat. Cut a piece of stiff plastic to size. Then tape the wire to your plastic card in the right position and hook the other end to your meter. Insert into a free PCIe slot.

this would be for measuring the rail voltage

for current you'd have to do this:

if ur thinking of doing what mfenn states please attempt on a Riser ... that way u can leave your motherboard immaculate from tampering.

they look like this.. can be found cheap on ebay and amazon.

and insert the ammeter in the path of the +12v rail pins

 

[sm625]

The riser thing is out of the question. I've gone that way in the past and will never go there again. BSODs and whatnot, due to violation of bus specs (trace lengths, impedence, etc.)

 

[imagoon]

Do it by inference. Power system note +12V load via inductive pickup on the powersupply, add card, measure again. Unfortuantely all other methods requires a riser or cutting traces in order to insert a device to measure the current or route it though an inductive pickup.

 

[richaron]

...BSODs and whatnot, due to violation of bus specs (trace lengths, impedence, etc.)

Source please? Not challenging you but honestly interested. I've not used risers myself, but have read a bit & I can imagine potential pros & cons.

 

[imagoon]

http://www.pcisig.com/developers/ma...c_id=6d37ec2f8543fc1f9d8ace6264d08b469f57e5f1

If you have a slot with dedicated channels, PCI-e has a trace limit 12inches (+-) The main issue that can arise is each connection add capacitance which can distort the signal.

I would harbor a guess that quality of the riser applies here. Cheap = might not be stable, better ones are used in servers regularly and should be fine.

 

[mfenn]

this would be for measuring the rail voltage

You're right. I saw voltage and then skipped right over the next word.