Xilence PSU issues; Several questions about my rig

[Lannister in the North]

Hi, I had some issues with PSU's lately and I have several questions on the subject.

I used to have a 600W Xilence PSU but then my computer started powering down randomly after I upgraded some hardware.

Current Build:

case: Antec P280
Mobo: Asrock Z77 extreme4
CPU: i5 3570k
8gb RAM
GPU: Gigabyte 7970 Ghz edition
a DVD Station
2 HDD's and an SSD
peripherals: USB headset and backlit keyboard (not sure if these have a lot of impact)

When using the 600W power supply, the video output is coming from the motherboard only, yet strangely the fans on the gpu are running.
When I unplug the DVD station, the case fans and peripherals the GPU does appear to work as intended.
So a few questions:

1. Can I safely assume that my GPU is powering itself off because it detects an inadequate power supply, even if it still has it's fans running? (Most likely yes but i'd like to be sure)
2. Could running my computer in this state possibly damage any components?
3. AMD urges never to run your computer without the power cables plugged into your GPU, because it can damage the GPU; Does this count for inadequate power as well? (What is the reason they urge this exactly?)
4. Could running my computer (temporarily) with an extra psu dedicated to my GPU cause any damage?


I then bought a Xilence 800W gaming edition; And everything was working fine.
However, not long after purchase it started intermittently making a strange rattling noise. When i put it on a PSU tester it gave me nothing to read and a strange smell started filling my nostrils.
When I tried the same tester a day later it appeared to be working fine, Amps and Volts were all good.

One question on this:

5. Can it be normal for a PSU to make a rattling noise? (I double checked if it was the fan but it wasn't)

I'd like to know because I don't want to fry my mobo with a defective PSU.

Anyway I RMA'd the noisy PSU.

Some further questions:

When I use various calculators and estimates around the web, I conclude my current build should have enough with 600W.
And if I were to put in another 7970 in Xfire I should have enough with 800W; According to the web.

6. Is this perhaps a false conclusion? Do I in fact need more or is the 600W Xilence PSU of poor quality and under performing?
7. Would the "Corsair TX850M PSU - ATX12V 2.31/ EPS12V 2.92 - 80 PLUS Bronze - AC 100-240 V - 850 Watt - active PFC" be enough to power my rig + another 7970 in Xfire? From what I looked up it should, but with my recent experiences I'm not so sure any more.

I know I'm asking a lot but the prospects of frying my mobo or damaging my gpu are realy weighing on my mind, and i'd like some clarity.
So any advice is greatly appreciated!

 

[Dark Lord of Tech]

They make very poor power supplies.

You need a : Seasonic , XFX , Antec , Corsair not CX Series.

 

[ko888]

...
I then bought a Xilence 800W gaming edition; And everything was working fine.
However, not long after purchase it started intermittently making a strange rattling noise. When i put it on a PSU tester it gave me nothing to read and a strange smell started filling my nostrils.
When I tried the same tester a day later it appeared to be working fine, Amps and Volts were all good.

One question on this:

5. Can it be normal for a PSU to make a rattling noise? (I double checked if it was the fan but it wasn't)

I'd like to know because I don't want to fry my mobo with a defective PSU.

Anyway I RMA'd the noisy PSU.

Some further questions:

When I use various calculators and estimates around the web, I conclude my current build should have enough with 600W.
And if I were to put in another 7970 in Xfire I should have enough with 800W; According to the web.

6. Is this perhaps a false conclusion? Do I in fact need more or is the 600W Xilence PSU of poor quality and under performing?
7. Would the "Corsair TX850M PSU - ATX12V 2.31/ EPS12V 2.92 - 80 PLUS Bronze - AC 100-240 V - 850 Watt - active PFC" be enough to power my rig + another 7970 in Xfire? From what I looked up it should, but with my recent experiences I'm not so sure any more.

I know I'm asking a lot but the prospects of frying my mobo or damaging my gpu are realy weighing on my mind, and i'd like some clarity.
So any advice is greatly appreciated!

5. No. It's not normal for a PSU to make a rattling noise. That would indicate that there is something loose inside the PSU. If it's a screw or solder ball that is floating around inside the PSU, due to poor manufacturing quality, then it can cause a short circuit. The strange smell may indicate that it was a loose solder ball that melted due to a short circuit.

6. 600W isn't enough for two Radeon HD 7970 graphics cards in 2-way CrossFire mode.

For a system using two AMD Reference Design Radeon HD 7970 graphics cards in 2-way CrossFireX mode AMD specifies a minimum of an 750 Watt or greater system power supply. The power supply should also have a maximum combined +12 Volt continuous current rating of 58 Amps or greater and have at least two 6-pin and two 8-pin PCI Express supplementary power connectors.

Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Sufficient Total Combined Continuous Power/Current Available on the +12V Rail(s) rated at 45°C - 50°C ambient temperature, is the most critical factor.

In theory the 800W model should be sufficient but I wouldn't trust PSUs made by Andyson. Andyson is the OEM for the Xilence 800W models and I've rarely seen any reputable reviews of any of their PSUs that have given them a decent rating.

7. The Corsair TX850 should be of better quality than any Xilence 800W model since the OEM used for the Corsair TX850 is better and the component quality is better.

 

[Lannister in the North]

First off thanks for the replies;

5. No. It's not normal for a PSU to make a rattling noise. That would indicate that there is something loose inside the PSU. If it's a screw or solder ball that is floating around inside the PSU, due to poor manufacturing quality, then it can cause a short circuit. The strange smell may indicate that it was a loose solder ball that melted due to a short circuit.

ok, maybe rattling wasn't a great description, it didn't sound like something was actually loose, more like a low frequency buzzing
Still, I wouldn't exclude your explanation.

6. 600W isn't enough for two Radeon HD 7970 graphics cards in 2-way CrossFire mode.

My current build has only one 7970; but i suppose the 600W Xilence cannot handle it sadly.
600W from a decent manufacturer should be enough for a single card setup though right? (no OC, stock cooling)

For a system using two AMD Reference Design Radeon HD 7970 graphics cards in 2-way CrossFireX mode AMD specifies a minimum of an 750 Watt or greater system power supply. The power supply should also have a maximum combined +12 Volt continuous current rating of 58 Amps or greater and have at least two 6-pin and two 8-pin PCI Express supplementary power connectors.

Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Sufficient Total Combined Continuous Power/Current Available on the +12V Rail(s) rated at 45°C - 50°C ambient temperature, is the most critical factor.

In theory the 800W model should be sufficient but I wouldn't trust PSUs made by Andyson. Andyson is the OEM for the Xilence 800W models and I've rarely seen any reputable reviews of any of their PSUs that have given them a decent rating.

7. The Corsair TX850 should be of better quality than any Xilence 800W model since the OEM used for the Corsair TX850 is better and the component quality is better.

OK, I will take your advice into account when considering PSU's.
I'll only buy from reputable manufacturers from now on.
Funny enough someone at work approached me today about his next PSU purchase, he was considering a Xilence. I was able to change his mind with thorough advice thanks to your answers. (and my experiences with Xilence)

 

[ko888]

For a system using a single Radeon HD 7970 GHz Edition graphics card AMD specifies a minimum of a 500 Watt or greater system power supply. The power supply should also have a maximum combined +12 Volt continuous current rating of 44 Amps or greater and have at least one 6-pin and one 8-pin PCI Express supplementary power connectors. Some models require two 8-pin PCI Express supplementary power connectors.

For a system using two Radeon HD 7970 GHz Edition graphics cards in 2-way CrossFireX mode AMD specifies a minimum of an 850 Watt or greater system power supply. The power supply should also have a maximum combined +12 Volt continuous current rating of 68 Amps or greater and have at least two 6-pin and two 8-pin PCI Express supplementary power connectors. Some models require two 8-pin PCI Express supplementary power connectors for each card.

The GHz Edition cards draw more power.