Question on 12v power connections B550 Pro4
Printed From: ASRock.com
Category: Technical Support
Forum Name: AMD Motherboards
Forum Description: Question about ASRock AMD motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=26047
Printed Date: 17 Jun 2024 at 5:36am
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com
Topic: Question on 12v power connections B550 Pro4
Posted By: Quexos
Subject: Question on 12v power connections B550 Pro4
Date Posted: 21 Jun 2023 at 9:03pm
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ASRock B550 Pro4: https://www.asrock.com/mb/AMD/B550%20Pro4/index.asp" rel="nofollow - https://www.asrock.com/mb/AMD/B550%20Pro4/index.asp This board has an 8-pin right next to a 4-pin 12v power connection. The manual states: "This motherboard provides a 8-pin ATX 12V power connector. To use a 4-pin ATX power supply, please plug it along Pin 1 and Pin 5" (IE: 4 of the 8 would be vacant?). I have both 4 and 8 pin connectors on my PSU. Is it intended that: 1. I plug in one 8-pin and leave the 4-pin unplugged. 2. I plug in a 4 (2x) pin into each (compatibility assuming my PSU only had 4 pins?). 3. Plug in an 8-pin and a 4-pin and fill it all up. I ask because I am having a difficult to troubleshoot problem where occasionally when powering up (not rebooting) from the off state (not sleep or hibernate), the PC will start to power on, and within a half a second a pop is heard in my speakers and it immediately goes powered down again, as if I yanked the plug out of the wall. Hit it again and iot powers on normally. Power Supply: Antec TruePower New TP750 (~10-12 years old now), running a Ryzen 5 5600 and Radeon RX 6600, with a couple M.2 SSDs, 2 120mm case fans + 120mm CPU cooler fan. The TP750 has powered much more "power hungry" parts in the past. |
Replies:
Posted By: Quexos
Date Posted: 21 Jun 2023 at 9:33pm
| Forgot to mention, the PC and Monitor are being run on a "Tripp-Lite avr750u Line Interactive 750VA 450W" battery backup PSU which I believe to be doing it's job since we get the occasional power flicker and it kept things running while the lights flickered off/on and the digital clocks reset. |
Posted By: eccential
Date Posted: 22 Jun 2023 at 9:14am
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All those connections are there to spread out the load. Since you're running R5-5600, which is fairly low power CPU, you don't need to worry. Here's how it goes: Minimum requirement: Half of the 8-pin connector using a 4-pin plug. This is done when your power supply does not have 8-pin plug. It should be enough for any 65W TDP processor. Typical usage: The entire 8-pin connector is used. The extra 4-pin connector is unused. It should be enough for any "normal" builds. Mostly overkill usage (major overclock, liquid nitrogen, etc.): Both 8-pin and the extra 4-pin are used. ------------ In your case, I see no reason to use the extra 4-pin connector. If the power supply has multiple 12V rails and the 8-pin and 4-pin are from different rails, I wonder if it can cause issues. If the rails don't turn on exactly at the same time, one rail could affect another rail. But I'm not a power supply expert. It sounds like you're tripping the over-current protection on your PSU. Since you don't have anything really power hungry in your build, I wonder if the PSU is on its way out. Over a decade is a long time. No electrolytic capacitor lasts forever, you know. Or maybe I am onto something with the previous paragraph. |
Posted By: Quexos
Date Posted: 22 Jun 2023 at 12:07pm
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Thanks. I had it in overkill mode then, just in case. I have new Power Supply (XPG Core Reactor 750w) coming in tomorrow now though, so probably will just go with the one 8-pin when Install that. I don't O/C at all, and tend to under-volt if anything. On the Antec TP750, the 8-pin and 4-pin come in the hardwired bundle, so I think they're on the same rail anyway. One by one I am just eliminating things to find the cause of the "power failure/surge". I put a new battery in my UPS backup yesterday and had another hiccup today, so it's narrowing right in that old Antec TP750. |
Posted By: Quexos
Date Posted: 23 Jun 2023 at 8:34pm
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New power supply is in and it is being powered with the one 8-pin CPU power connection (second 4-pin vacant). Been solid through a full day of stopping and starting while playing with Linux, Windows and making backup images from a Macrium rescue disk (usually when I had the power on problem). It's a little too soon to declare it "fixed" but I am gaining some confidence that it was just the power supply, which would not really be surprising since it was a quality part but ~14 years old. Thanks again for the info. |
Posted By: Xaltar
Date Posted: 23 Jun 2023 at 9:58pm
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Unfortunately even the best built PSUs fail eventually. These days it's relatively easy to get them recapped. I have done it with a few of my veteran PSUs that lasted and never gave me issues. I only use them for test units and budget builds but it's nice to know that they were built right. Give it a few days of regular use, if all is well by then you can rest easy  ------------- 
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Posted By: eccential
Date Posted: 23 Jun 2023 at 10:21pm
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"These days it's relatively easy to get them recapped." I was going to mention that. Most people don't bother in, well, cushy countries, but it's not a bad idea to fix stuff and keep using, especially if it's relatively easy to do. But if you got 14 years out of it, I'd say you've done better than many. :) Your choice of these big 750W power supplies made me do a double take, though, seeing as how your components are all pretty low power. I've NEVER bought a power-supply past 500W, but I go for the best (Seasonic Prime, etc.). But I'm weird. I mean, who else buys a 5800X3D to run with boost completely disabled? (3.4GHz max). My CPU will never see voltage higher than 1.0V as long as I own it. Laugh. |
Posted By: Xaltar
Date Posted: 24 Jun 2023 at 2:55am
I have had 8 of my 16 cores disabled on my 2950x since about a month after I got it Why use more power than I need to when 8c/16t is more than enough for all the tasks I use the system for. I also have my VCORE set to 1.0v and capped my frequency to 3.5ghz. Power is expensive here. When I need to use the system's full power for a complex render I can just set my performance profile in Ryzen Master and restart the system. As for the recapping, it's becoming more common these days with so many guides on youtube and how cheap/easy it is to do. You can revive a great PSU and even improve on it by replacing the caps with higher quality ones than the originals. -------------
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eccential wrote:Posted By: Quexos
Date Posted: 24 Jun 2023 at 9:36am
I never thought of them as big. I think of 1000+ watts as big. It's more than I am currently (pun intended) drawing, but I'm of the mind that I should have a little extra, because I'm cynical and figure manufacturers are usually fudging the numbers a bit (some more than others), so If you want an actual 600w PSU, buy an "700w", and because I want it to run "easy" and cool at like 50-60% capacity rather than "hard" at 80-100%. Presumably why I got 14 years constant use out of the last one. Plus to future proof in case (pun intended) 2 years from now all the rage is some new tech graphics card that draws 500w all by itself, or I just decide to turn it into a file server with 20 spinning HDDs or something. But yeah, I could probably stick a 400w PSU in and be fine. |
Posted By: Xaltar
Date Posted: 24 Jun 2023 at 10:19pm
I do the same with my systems. Ideally you want to run at around 60-70% load for optimum efficiency and cooling. PSU efficiency tends to be at it's peak around these load levels, depending on the spec. What you don't want is to be running at <90% or consistently >20%, efficiency is terrible in those ranges. This is less of an issue today than it used to be with most (good) PSUs offering comparable efficiency across the spectrum, particularly with 80+ Gold or above. Even here though, keeping your PSU under lighter load will always equate to a longer lifespan. -------------
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Posted By: eccential
Date Posted: 25 Jun 2023 at 2:23am
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Xaltar beat me to it again. The only real -issue- quirk with using too-much power supply is that the efficiency at very low load (under 20% load) tend to be pretty bad. They have been improving on this, though (search for differences among Gold, Platinum, and Titanium rated power supplies). The requirements are different for 20%, 50%, and 100% loads. Among my systems, one of my favorite is a Ryzen 5 PRO 4650G system, using a Mini-Box M3-ATX power supply, which is a tiny plug-type power supply rated for just 125W. It has better than 94% efficiency at 50% load, and can be powered from wide voltage ranges. It's great for supplemental solar power *without* batteries, when used with Mini-Box's Y-PWR (wall power + solar panel power). It will run 100% solar when there's enough sun, and no need to deal with batteries. I'm generally a low-power kind of guy, after all. |
Posted By: Quexos
Date Posted: 27 Jun 2023 at 9:03pm
He beat me too, but yup, I figure a 1000w would put me in that 20% low efficient range and a 600w would put me in the 90% working too hard range. The reviews on the XPG Core Reactor I got say it is very efficient at lower loads so I think I am right where I want to be. Basically just an improved version of what I had, that served me very well for a decade. |