RGB Limit on Motherboard

[RealBrandonMcGowan]

Hello, I have giving myself such a headache trying to figure this out. I am going to get the Asus's ROG Strix B450-I Gaming and I want to get 2 of Cooler Master's MF140R ARGB and 1 MF120R ARGB. I also want to add some amount of CableMod's Addressable RGB Strips. Asus's site states that the motherboard supports "WS2812B addressable RGB LED strips (5V/Data/Ground), with a max power rating of 3A (5V) and a max of 60 LEDs". I cant find anything that tells me how many LEDs the fans have or the 30cm and 60cm strips, I'm not sure if the fans even count towards the 60 LEDs or not. I will also get Cooler Master's MasterLiquid ML120R RGB and I have the same problem (Unsure of the # of Leds). If this made any sense what soever I hope you can help me.

LED Strips: https://cablemod.com/product-category/led-strips/addressable

Fans: http://www.coolermaster.com/cooling/case-fan/masterfan-mf120r-argb and http://www.coolermaster.com/cooling/case-fan/masterfan-mf140r-argb

Radiator: http://www.coolermaster.com/cooling/cpu-liquid-cooler/masterliquid-ml120r-rgb

Motherboard: https://www.asus.com/ca-en/ROG-Republic-Of-Gamers/ROG-STRIX-B450-I-GAMING

[mariushm]

The 60 led limit is per rgb connector on motherboard... it's just a number picked based on maximum current (3A) and total led strip length. Fans don't count, those leds are powered from 12v in fan connector.

 

Each RGB led can consume up to around 15-20 mA per color, so let's go with a simple round 50mA per led. 60 leds then give you 60 x 50mA = 3000mA or 3A.

 

The motherboard has no way of knowing how many leds are on a strip, they just say 60 to protect themselves, so you won't damage the connector by connecting a strip which sucks more than 3A...

If you have a single color led strip, or a strip that's more efficient or lower power, let's say one with max 5mA per color (like a high eff. red only strip) or 15mA per rgb led, in theory you could have 3000mA / 15mA = 200 leds.

 

Length limitation: the longer  the strip , the bigger the losses ... for ex. first led may get 5v, the 15th led may get 4.9v , the 30th led may "see" 4.7v and by the 60th led you may have 4.5v on the strip.. there's losses in the thin wires between the leds.

Some leds can work with as little as 3v others need at least 4.5v to work, so by saying 60 , they're also making sure user won't say the motherboard is faulty when the last 10-20 leds on a 100 led strip don't work or are less bright than the others.

 

 

 

 

[SRT10]

Old thread I know - mariushm, I ran into this problem most recently adding 3 x Phanteks M1 Digital RGB strips,  Board has 2 Addressable and 2 Non Addressable headers, figure I could just daisy chain 3 M1 strips together (70 leds each apparently I now know) and plug into 1 addressable header.....Newp no go.  I got 1 fully illuminated, then half of 1, then 1 fully not functional.  Returned 2..thinking 2 were bad and doh!  same result.  So now I run 1 full to an addressable header and 2 daisy chained to another addressable header with half of the last strip not working but it's run like that unfortunately hidden within the case, regardless it's expensive at $32+tax each strip to accept and just run 1 at 1/2 function.  I'm searching around to figure my boards header support per led if that is the issue or any other soluitions.