Monday, September 14th 2020
Seasonic Details 12-pin Modular Cable, Free for GeForce 30 Series Owners
Seasonic today shared with us some additional details regarding its 12-pin Molex MicroFit 3.0 modular PSU cable, and how it plans to market it. If you've read our NVIDIA GeForce RTX 3080 Founders Edition Unboxing Preview, you'll know that NVIDIA ships its Founders Edition cards with a printed warning not to use any third-party adapters to convert 8-pin PCIe power connectors to the 12-pin connector. The warning also asks you to use the included adapter, and that using a third-party adapter would void the warranty. There's no clarity from NVIDIA on whether modular cables that plug directly into a modular PSU and put out 12-pin connectors strictly fit this description, as they're not "adapters."
Seasonic believes that its cable is a perfect match for NVIDIA's GeForce RTX 30 series graphics cards. The cable uses 16 AWG wires. Each 12 V pin of the connector is rated for 9 A current, which means the cable is capable of ferrying up to 540 W of power. On one end of the cable are two 8-pin 12 V connectors (which plug into the 12 V modular back-plane of your PSU), and on the other is one 12-pin connector. The cable is 75 cm in length. The cable is compatible with the company's Prime, Focus, and Core series modular/semi-modular PSUs.
If you own a Seasonic PSU (Prime/Focus/Core) and an NVIDIA GeForce RTX 30 series graphics card that has a 12-pin input, then you're eligible to receive the cable free of charge. Later this week, on Wednesday, the Seasonic website will have an online form with which you can request the cable. You'll have to provide the serial number and a photo of the PSU, and proof of purchase and serial number for the GeForce 30 graphics card.
Certain RTX 30 series graphics card SKUs ask for 750 W (or higher) PSUs in their system requirements; while certain other RTX 30 series cards mention 650 W in their system requirements. Be sure that the PSU you're seeking your modular cable for meets the system requirements of the graphics card you own. Seasonic mentioned that it has limited supply of the cable, and hasn't yet decided if they want to sell the cable in the open market. The company will take a call on this by year-end.
A video presentation by Seasonic follows.
Seasonic believes that its cable is a perfect match for NVIDIA's GeForce RTX 30 series graphics cards. The cable uses 16 AWG wires. Each 12 V pin of the connector is rated for 9 A current, which means the cable is capable of ferrying up to 540 W of power. On one end of the cable are two 8-pin 12 V connectors (which plug into the 12 V modular back-plane of your PSU), and on the other is one 12-pin connector. The cable is 75 cm in length. The cable is compatible with the company's Prime, Focus, and Core series modular/semi-modular PSUs.
Certain RTX 30 series graphics card SKUs ask for 750 W (or higher) PSUs in their system requirements; while certain other RTX 30 series cards mention 650 W in their system requirements. Be sure that the PSU you're seeking your modular cable for meets the system requirements of the graphics card you own. Seasonic mentioned that it has limited supply of the cable, and hasn't yet decided if they want to sell the cable in the open market. The company will take a call on this by year-end.
A video presentation by Seasonic follows.
35 Comments on Seasonic Details 12-pin Modular Cable, Free for GeForce 30 Series Owners
Remember AM4, most of the better brands provided free or cheap mounting kits for that too...
I do have a Seasonic PSU though, we'll see.
Their note : The cable uses 16 AWG wires. Each 12 V pin of the connector is rated for 9 A current, which means the cable is capable of ferrying up to 540 W of power....This assumption it does worth in value equally to a roll of toilet paper.
Did they ever load 16 AWG with 9 Ampere so to discover how great is the loss of voltage ?
I would expect a video with measurements in to a laboratory with real electrical test and measurement equipment of some quality.
16g wire should be fine. MicroFit 3.0 pins are not.
Thank you for your input on this.
Please note that we only follow NVIDIA's recommendation in order to provide the best cable possible.
Best Regards,
Seasonic Team.
Anyway, looking at the connector alone, 9A is probably the single circuit current capacity with good cooling all around individual contacts. 12-circuit current capacity would be about 5-6A. Maybe 9A if you sandpaper each pin and wet them with mercury or something before mating....
5A x 6 (wire pairs) comes to 30A
30A x 12V = 360W
Remember that these wires are free floating in an actively ventilated case, so I think even more than 5A on 75cm should not be a problem!
16 AWG is rated at 13 Ohm per km, so its about 0,0013 Ohm eespectively 0.0013 W per Meter of cable per amp per wire. That makes it 0.0156 for 12 Wires per Amp. For 5A that makes 0,078W. And all this is for a meter, so for 0,75cm is only 3/4 of that.
That wont get even warm!
Nevertheless, I'm sorry, but your wire dissipation calculation is off by two orders of magnitude. 16 AWG is indeed 13 Ohm/km, which is 0.013 Ohm/m, which is indeed 0.013 W/m/A. But that's end there because resistive power dissipation is not linear, but proportional to the square of current. One meter of 16 AWG wire carrying 5A would dissipate 0.013 * 5^2 = 0.325 W which is still fairly acceptable. Drooping 65mV in the process. 12 Wire total dissipation would be 3.9 W. One meter of 16 AWG wire carrying 9A on the other hand would dissipate ~1W, drooping 117mV. (IMO still acceptable, but someone might freak out looking at the droop).
The connector on the other hand, is rated at 10mOhm initial, with additional 20mOhm aging. These alone would dissipate 1-2 Watts per contact at 9A. That might not look much and not many cares, but power connectors do heat a lot, especially one with small physical size.
I have no doubt regarding positive intentions, but in this community they are members which they also have advanced understanding of product specifications.
We would expect crystal clear incoming data regarding actual electric properties even of a simple in design item as is your product which comes with a length of wires and connectors.
NVIDIA supplied their sort in length cable with 12P connector, which this is going to be used with full length wires them coming from the PSU it self.
Not all PSU (non modular) come with identical length of PCI-E 6+2 wires and connectors and wires resistance this will vary.
From the other hand I would expect one modular harness as is your product, this to be escorted with test report this be a proof that this is electrically loss free product at full load.
Fill free to illustrate of how I did similar testing at my humble laboratory to your engineers, at 8P CPU connector.
At my Blog I do not give away actual test results from the taken electrical measurements, I am just motivating people to use best practices by the use of electrical measurements and qualifying equipment.
www.ittsb.eu/forum/index.php?topic=1604.msg3982#msg3982
The second method as test that it can be used for a product QC verification this is Resistivity benchmark.
Resistance of its wire among with the pins attached it should be known, so us (people performing product support and repairs) to be able to identify when a 12P cable has healthy all pairs of wires in that harness.
www.ittsb.eu/forum/index.php?topic=1508.0
While I do not plan getting any RTX 3080, I am willing to perform electrical measurements of precision at the PSU and 12P cable that Seasonic considers as ultimate choice for gamers .