I May Need to Change My PSU (!?)

[hujan86]

While several tech websites gave Cooler Master GX 750W favorable reviews and have recommended it to potential buyers, but one website did not. According to this article at Hardware Secrets, the GX 750W has a MAJOR flaw: high electrical noise and ripples at 80% (600W) and 100% load (750W).


Hardware Secrets tested PSU in terms of electrical noise in addition to Voltage Regulation. While voltages are stable at high load, noise level was said to be above the 50mV limit which could overload and harm other PC components. Hardware Secrets recommended 450W as the safe limit.

My PC system specs are as follows:
CPU: Intel Core i7 2600 3.4GHz (cooled by Cooler Master Hyper TX3)
Memory: 2 X Kingston 4GB DDR3 1333MHz
Motherboard: ECS H67H2-M
Graphics: Powercolor Radeon HD6870 2GB GDDR5 Eyefinity 6
SSD: Patriot Memory Pyro 60GB SATA3
HDD: Western Digital 640GB Caviar Blue SATA2
Optical Drive: LG 22X DVD Rewriter SATA
PSU: Cooler Master GX 750W


Generally, how much is the load in % during heavy gaming (e.g. playing Crysis 2 at max. settings for hours)? Is my PC in danger of getting fried due to overload from the Cooler Master PSU?

[profJim]

Re: I May Need to Change My PSU (!?)

I've found that HardwareSecrets, JonnyGuru, HardOCP, techPowerUp and PCPER are the best sites for thorough power supply reviews where they perform detailed reviews and stress power supplies to see if they meet all specifications at elevated temperatures; 40^o - 50^o (C). Usually, but not always, they arrive at similar conclusions.

JonnyGuru reached a similar conclusion in their GX 750 psu review JonnyGURU - Coolermaster GX-750 750W. Both of these reviews were performed when it was introduced in 2010. It's possible that Cooler Master has made improvements since the introduction, but there is no way to know for sure. Some of these sites request a second unit to review when a name brand psu has major performance issues. In the JonnyGuru review, they requrested a second unit for testing but never received one.

The best power supplies include Seasonic, Enermax, Corsair, and many Antec models. In the past year or so, some Super Flower made power supplies have produced outstanding results. Keep in mind that most power supplies are made by OEMs where the vendor uses existing platforms that are modified to the vendor's specifications. The best units have excellent voltage regulation and very low electrical noise (ripple), and easily meet and exceed specifications even at high temperatures. Many of the psu vendors use psu platforms made by several OEMs. Many name brand power supplies are mediocre at best. Using cheaply made power supplies can lead to stability issues with your system, even if you are not overclocking.

When running GFX benchmarks, my older P35 system draws over 300 watts from the wall and with SLI it probably draws up to 550 watts. With a 90% efficient psu, the psu output would be approximately 270 - 500 watts. A less efficient 80+ bronze rated psu will provide the same output, but will draw up to 8% more power from the wall. The general recommendation is that for extended high power output, a psu should provide 80% or less of it's maximum rated power. I'm using a Seaonic made, Antec TP-750 New power supply in my SLI system.

As you can tell from my signature, I'm a firm believer in buying high quality power supplies, as they are the foundation of your system. A top performing power supply means that the voltage regulating circuity in your motherboard has a much easier time.

[hujan86]

Re: I May Need to Change My PSU (!?)

It's hard to believe that the unit reviewed by JohnnyGURU was a pre-production unit, as claimed by Cooler Master. Hardware Secrets performed its test in February. That's four months earlier and Cooler Master didn't do anything to rectify it.

[profJim]

Re: I May Need to Change My PSU (!?)

I like most Cooler Master products, but I've seen very few Cooler Master psu reviews where the overall performance was very good or excellent. It looks like your GX-750 power supply is OK if the psu power output is 500 watts or less.

With the holiday sales fast approaching, now is a good time to buy a top tier psu if you are in the USA. I bought my Antec TP-750 New power supply for $70 (after rebate) on Cyber Monday two years ago. Do your homework by seeing what the best psu review sites have to say before you buy a power supply. There a quite a few excellent 80+ bronze rated power supplies. In general, power supplies with an 80+ silver, gold, or platinum rating will use the best quality components, run with much lower noise levels and offer the best voltage regulation with very low ripple.

[dJabba]

Re: I May Need to Change My PSU (!?)

[half off-topic] thanks for the links to those sites, will have to check more up on my Chieftec Nitro 88+ 650W, a quick scan seems it has a little trouble on the 3v rail - might be the reason for some of my trouble now and then (though my system shouldn't go much above 400-450w on load).
Initially i bought it cause it was cheap for the features and efficiency and it does great on the other rails (so far i could only find 750w reviews with extensive tests though).

[profJim]

Re: I May Need to Change My PSU (!?)

I forgot to include techPowerUp! - The latest in hardware and gaming in the good guy psu review list.

[hujan86]

Re: I May Need to Change My PSU (!?)

Thanks for the list of sites. I'll make sure to read the reviews first at these site even before considering buying a new PSU. Prior to my discovery at Hardware Secrets, I only took account the brand name and wattage values.

[profJim]

Re: I May Need to Change My PSU (!?)

Glad to help out.
Being an informed consumer is the best protection against buying inferior products.

JonnyGuru, HardOCP and TechPowerUp recently published reviews of the newly released Seasonic 1000 watt 80+ platinum rated power supply.
Pricey? yes, but it's an amazing unit.
JonnyGURU - Seasonic Platinum 1000W
[H]ardOCP - Seasonic Platinum-1000 1 Kilowatt Power Supply Review
Seasonic Platinum-1000 1000 W Review - Page 1/9 | techPowerUp

[hujan86]

Re: I May Need to Change My PSU (!?)

I just realized something. The GX 750W featured in all the reviews doesn't have the "Bronze" label both on the unit and the packaging. The review units are 80+ certified but mine is 80+ Bronze.

I may have based my fears on outdated info.

[profJim]

Re: I May Need to Change My PSU (!?)

CoolerMaster tested power supply list: Ecova Plug Load Solutions
Where you will find their reports for the older and newer Cooler Master units:
RS_750_ACAA_A1 (2007) http://www.plugloadsolutions.com/psu...LUS_Report.pdf
RS-750-ACAA-E3 (2010) http://www.plugloadsolutions.com/psu...50W_Report.pdf
RS-750-ACAA-D3: (2011) http://www.plugloadsolutions.com/psu...50W_Report.pdf

80Plus certification testing deals with meeting different efficiency rating levels. They do not stress test power supplies. I'm not aware of their tests dealing with voltage regulation or electrical noise (aka ripple).

80Plus website: Ecova Plug Load Solutions
80Plus Test Protocol: http://efficientpowersupplies.epri.c...tocol_R6.5.pdf

throughout the test.

The top tier psu review sites perform additional stress tests up to 40^o - 50^o (C) which is a much more demanding and realistic test.
Some/many units cannot stay within spec at these higher temperatures and they often have lower electrical output at higher temperatures.
Any review site that only uses a DMM (digital multi-meter) and/or computer software to monitor psu voltages should be avoided.

Never run a power supply at more than 80% of its maximum rated output for an extended period of time, such as when gaming.

[hujan86]

Re: I May Need to Change My PSU (!?)

I just thought Cooler Master has made some improvements to the model's components after the reviews. A 80+ certified PSU can't suddenly have 80+ Bronze certification without any reason e.g. modifications to the components, right? Maybe in the process, they did something on the electrical noise problem as well.