Windows 7: PSU upgrade.

Have rebuilt my PC today, new mobo, HDD, more RAM, powered sound card and Win 64 bit.

I picked up a s/hand PSU (Antec 650W) but it would not run. Gone back to old 500W PSU but it only has a 4 pin mobo connector instesd of 8.

Everything is now working but I need to upgrade the PSU. Is there any harm in running the 4 pin 12V for now? I will also add a new video card which may need power - how big a PSU should I buy? What brands are recommended.

I will update my system info.

Corsair, Antec, Seasonic are good brands.
650 watt should do you fine, that is what I am running and I have a ton of shit in my case.

Hi,

It's not advised to use a 4 pin on a 8 pin motherboard, you can find more information on this site about it: All about the various PC power supply cables and connectors

I myself use a Corsair PSU (HX850W), had good reviews and i'm very happy with it.

Here's a good site to calculate the wattage you need: Enermax Power Supply Calculator

Also good to know is that it's not only the wattage that's important but also how much amperage the 12v line has.

MK2

You should use the 8-Pin if possible.

I use a 550W OCZ PSU it has both 4 and 8 Pin. Naturally, I use the 8.

Recommend that you use 8 pin, parts of your mobo are not being provided power.

Get yourself one of THESE

IMO, it would be safer to find a 650W PSU with the 8-Pin.

The last couple of motherboards I have purchased have 8 pin 12V sockets, but they came with plugs that blocked four of the pins. I believe that was to make iteasy to know how to insert the 4 pin plug. That suggests that most CPUs don't really need the extra current. (I haven't seen specs on that.)

If your system is running reliably with the 4 pin connector, I suggest that you not worry about it. I built up a system a few months ago that had an 8 pin socket; it runs perfectly reliably with a 4 pin plug. (Decent Antec PSU.)

Of course, on the newer systems, I removed the plug and used my 8 pin power connector. Because I could. (And I overclock.)

I'm also running the Antec Earthwatts 650 PSU and it's a real PowerHouse!
I'm running three SATA II hard drives, two DVD burners, 6 gig's of ram, AMD 5200+ X2, 64 cpu and a floppy drive and multi-card reader. OH, and 12 cooling fans.

So I'm curious what has happened to your 650 that it won't start. I'd almost have to suspect that if it wasn't hit by lightning, then it's not connected properly.

Just curious......

It's perfectly fine to run a 8-pin mobo off a 4-pin connection. As long as you aren't overclcking that is.


All PSU's have duds for varying reasons. Probably why it was 2nd hand...