SOLVED What size PSU should I get?

[neo668]

Hi guys/gals. Would like your help in choosing a PSU.

Just realized that the fan of my current PSU - an Antec TruPower Trio TP3-550 - is not turning. The 2 case fans I have connected to the PSU's fan connectors don't run as well. Other than that my computer runs normally. But I guess it's time to get a new PSU as this TP3 has seen 5/6 years of excellent service.

I'm thinking of getting a good PSU but spend as little as possible. I'm not a gamer so I think I can get by with lower powered PSUs and use the savings to get a better model. My question would be what max wattage should I get given that I have the following hardware in my system?

CPU: AMD Phenom II X6 1090T
CPU Cooler: Cooler Master Hyper 212 Plus
MB: MSI 990XA-GD55
Graphic: MSI ATI Radeon HD 5450
Ram: Corsair Vengeance DDR-3 1600 2x4GB
Harddisk: 1 x SSD 120GB, 2 X Seagate Green 2TB, 1 X Seagate Green 1TB
Fans: 2 x 12cm (CPU), 3 x 12cm (Case)
OS: Win 7 x64

I've read all the stickies and PSU recommendations in the Power Supplies and Electronic Devices section of this forum. I have an idea what brands I should consider. I'm just clueless as to what power spec I should get for my system.

Any advice would be greatly appreciated. Thank you.

 

[Bobnova]

Corsair CX 430w is often on sale and will run that system without breaking a sweat. I've seen it as low as $20.

A 200w unit could run that system if you aren't overclocking.
If you are, a 250w or 300w is plenty.

Seasonic makes some nice Bronze 300-350w units.


EDIT:
Here's the Corsair unit, this is what I would get: http://www.newegg.com/Product/Product.aspx?Item=N82E16817139026

 

[neo668]

Thanks Bob. Didn't know I could go as low as 300W. Will check around to see which is the best PSU I can get in the 300W to 500W range.

PS I overclock from time to time. And I was also considering a Corsair HX series.

 

[Knufire]

At MOST I'd get a Corsair CX500.

 

[cyberfish]

Have you tried just replacing the fan? That might be the cheapest option, if the PSU is still functional.

Most PSUs use standard sized fans.

Make sure to leave the PSU disconnected (from the wall) for a few hours before opening it, though. There are big capacitors inside that store a lot of energy at high voltage.

 

[manu2b]

Have you tried just replacing the fan? That might be the cheapest option, if the PSU is still functional.

Most PSUs use standard sized fans.

Make sure to leave the PSU disconnected (from the wall) for a few hours before opening it, though. There are big capacitors inside that store a lot of energy at high voltage.

^+1

 

[neo668]

Have you tried just replacing the fan? That might be the cheapest option, if the PSU is still functional.

Most PSUs use standard sized fans.

Make sure to leave the PSU disconnected (from the wall) for a few hours before opening it, though. There are big capacitors inside that store a lot of energy at high voltage.

I suspect it is a part in the PSU that regulates the fan that has gone dead, and not the fan itself. My present PSU has 2 "Fan Only" connectors by which it also controls 2 of my case fans. These 2 case fans are also as motionless as the PSU fan. I remember seeing them turn everytime I opened up my case. But not lately.

I've also been doing some reading on PSUs and just discovered that there are semi-fanless PSUs. These PSUs will stop the fans and operate without them if it is cool enough. I wonder if this is the case with my PSU.

Anyway I'll test the PSU again before I rush out and get another one. So far it is working just fine.

 

[cyberfish]

I suspect it is a part in the PSU that regulates the fan that has gone dead, and not the fan itself. My present PSU has 2 "Fan Only" connectors by which it also controls 2 of my case fans. These 2 case fans are also as motionless as the PSU fan. I remember seeing them turn everytime I opened up my case. But not lately.

I've also been doing some reading on PSUs and just discovered that there are semi-fanless PSUs. These PSUs will stop the fans and operate without them if it is cool enough. I wonder if this is the case with my PSU.

Anyway I'll test the PSU again before I rush out and get another one. So far it is working just fine.

It's possible that one of the fans have failed short, and the PSU's current limiter kicked in and cut the rail to all the fans. The easy way to test that is to disconnect the fans one by one (including the one inside the PSU, following precautions), and see if the other ones start running.

 

[neo668]

It's possible that one of the fans have failed short, and the PSU's current limiter kicked in and cut the rail to all the fans. The easy way to test that is to disconnect the fans one by one (including the one inside the PSU, following precautions), and see if the other ones start running.

I will try this. Excellent advice. Thank you.

If there is a problem with one of the fans it will have to be the PSU fan. This is because I have now directly connected the two case fans to the "Fan" headers on the mobo and they are running. Whereas the PSU fan is still motionless.

I have never taken a PSU apart. Hope it is not too hard.

 

[cyberfish]

I have never taken a PSU apart. Hope it is not too hard

Consists of unscrewing 4 screws, and pull .

Remember to wait a few hours disconnected first!!

 

[neo668]

Consists of unscrewing 4 screws, and pull .

I can do that.

 

[Bobnova]

I would guess that a capacitor on the fan circuit died, personally.

 

[neo668]

I tried changing the PSU fan today. The task wasn't difficult but it was unsuccessful. The PSU was still functional but the fan would not turn. I think I'm just going to get a new one for peace of mind. Around 500W for future proofing. I've already printed out the list of most recommended PSUs and will see what my neighborly computer store has available.

Thanks to all.

 

[neo668]

So I got a Seasonic M12II 520 Bronze to replace the old Antec. But I was really curious as to how much power my system was actually using and whether my new 520W PSU would be sufficient should I add new hardware in the future, or upgrade to BD or PD. I just had to go out and get myself a Kill-A-Watt to confirm for myself.

My system's hardware is exactly those listed in Post #1. The results are as follows.

Computer Turned Off 7.1W
Logged Off 111W
Idle On Desktop 128W
Some Light Work 163W
Prime95 (Max Wattage During 20-Minute Run) 310W

I guess my 520W PSU should be about right.

PS Forgot to mention that my rig is OD'd to 3.8GHz (stock 3.2GHz).

 

[manu2b]

Thanks, useful info.

 

[cyberfish]

Running Prime95 and Furmark at the same time will probably give you the absolute highest power consumption.

Also, keep in mind that you are measuring input to the power supply. You'll need to multiply it by power supply efficiency to get power delivered to components.

For example, assuming your power supply is around 80% efficient, if it draws 310W, it's only giving 248W to the components. And power supplies to rated for power supplied to components (so a 520W power supply would be drawing 650W at full load assuming 80% efficiency).

 

[neo668]

Running Prime95 and Furmark at the same time will probably give you the absolute highest power consumption.

Also, keep in mind that you are measuring input to the power supply. You'll need to multiply it by power supply efficiency to get power delivered to components.

For example, assuming your power supply is around 80% efficient, if it draws 310W, it's only giving 248W to the components. And power supplies to rated for power supplied to components (so a 520W power supply would be drawing 650W at full load assuming 80% efficiency).

Yes, I understand. Thank you.