Question 1100 Dell PSU not working on modern motherboards

[Alberto Scorrano]

I have an "old" alienware area 51 with intel i980x, 12 Gb RAM and two radeon hd5770 working with crossfire.

I recently decided to build up a new computer from scratch, using AMD Ryzen 3800x, 8 GB ram (just to start) and my old fully working video cards (graphics is not my priority in the system, I will upgrade them later). As a mobo I try with a MSI x570 gaming plus from amazon warehouse. I use my old alienware PSU (A dell 1100 Watt H1100EF-00, fully working with my alienware!!!).

The new mobo won't start, so I think it's a bad mobo because it's from amazon warehouse. I change it with a new asus x570 pro but same thing, it won't start! I then try with another very old 350 Watt from my grandpa's computer and it works!!!

So my question is: why does the Dell PSU work with my old alienware even if it's overclocked (4.5 Ghz), but won't work at all with these new modern mobos? I used the usual 24 pin connectors for ATX and 8 pin connector for CPU. Thanks to anybody who will clarify this mistery!

 

[Phillip Corcoran]

The MSI x570 Gaming Plus also requires a 4-pin as well as the 8-pin for CPU power.

I assume that your Dell PSU does not have the required 4-pin?

 

[Alberto Scorrano]

Thanks for your reply. As both MSI x570 Gaming Plus and Asus x570 Prime Pro manuals state, 4 pin connector is only required in case of heavy overclocking. That's not required. Anyways no, my Dell PSU doesn't have that connector, but so doesn't my old grandpa's PSU.

 

[jonnyguru]

I have an "old" alienware area 51 with intel i980x, 12 Gb RAM and two radeon hd5770 working with crossfire.

I recently decided to build up a new computer from scratch, using AMD Ryzen 3800x, 8 GB ram (just to start) and my old fully working video cards (graphics is not my priority in the system, I will upgrade them later). As a mobo I try with a MSI x570 gaming plus from amazon warehouse. I use my old alienware PSU (A dell 1100 Watt H1100EF-00, fully working with my alienware!!!).

The new mobo won't start, so I think it's a bad mobo because it's from amazon warehouse. I change it with a new asus x570 pro but same thing, it won't start! I then try with another very old 350 Watt from my grandpa's computer and it works!!!

So my question is: why does the Dell PSU work with my old alienware even if it's overclocked (4.5 Ghz), but won't work at all with these new modern mobos? I used the usual 24 pin connectors for ATX and 8 pin connector for CPU. Thanks to anybody who will clarify this mistery!

The Alienware Area 51 power supply is not a standard ATX pinout. You're lucky you didn't kill the new motherboard with it.