no worries about that. Corsair vx 450 has been found to give 550-600W during testing so i hope you get the idea
no the VX450 can sustain a max load of 571w,
all the while maintaining its 80+ efficiency
it could well be labelled 550w PSU
but corsair likes to underrrate its psus
likewise cx400 can sustain a max load of 481w
so it could well be labelled 450w psu
CX 400 would handle HD5770 like a sehwag handles his bat !
it will do the job
i am buying the same config with cx 400 and hd5770
571W from the psu or power draw at the mains?
Can you please provide some links/s for the same?
From what i have read, a little for sure.
That much lower, i am not sure- coz the marketing guys wouldn't have allowed that i feel.
Jokes apart, may i please request you to provide any links for your claims?
Will help me and anyone else gain some concrete info/knowledege.
Don't know about the under-rating thingie but most Corsair power supply unit's make some of the other offerings in teh respective price segments look over-rated for sure.
All said, the VX450 has proved itself to be one stable and fairly reliable performer when used within it's specified ratings.
Corsair CX400W Power Supply Review | Hardware Secrets
Corsair VX450W Power Supply Review | Hardware Secrets
a Overload Tests
Hardware Secrets Golden Award
We were really curious b to see how much power this unit could really deliver, because by the project used we suspected it could deliver far more than what was labeled – especially because we had already reviewed Antec EarthWatts 500 W, which uses the same design, and it is not only labeled at 500 W but could deliver up to 577 W.
We tried to see not only the maximum power we could extract from this power supply with it still working inside its specs, but also if all its protections are working correctly c. As you know by now, power supplies usually burn when we try pulling more than it is capable of handling if it doesn’t feature overload protection (OLP or OPP; these two acronyms mean the same thing).
Since we were already pulling from the +12 V output almost the maximum our load tester can deliver to this output – 33 amps – we removed the power supply EPS12V connector from +12V1 input and installed it on the +12V2 input from our load tester. Then starting from pattern number five described in the previous page we started increasing current until the power supply turned off. We figured out that if we pulled more than 44 A (528 W) from +12 V (22 A from the motherboard, video card and peripheral cables and 22 A from EPS12V) the power supply wouldn’t turn on. Phew, we were really cold sweating expecting the worst – that this power supply would explode. But since it shut down, we could testify that overload protection was in action, which is terrific.
Then we increased current on +5 V and +3.3 V to see if we could pull even more. Under the current configuration if we pulled more than 7 A from these rails the power supply would shut automatically down.
With this maximum configuration (44 A from +12 V, 7 A from +5 V and 7 A from +3.3 V – i.e., a total of 596 W!) the power supply would turn on and work for around 30 seconds, after that the power supply would shut down due to overload. Isn’t that great to have a power supply with overload protection in action? You can do whatever you want and it doesn’t explode!
We decreased two amps from the +12 V output and we could make our 450 W power supply to work stable at 570 W at 48º C and with 81% efficiency! d Holy cow! You can see the summary for this test in the table below
...
Under this test all outputs were within specs and noise level was still very low, 47 mV at +12V1, 58.2 mV at +12V2, 19.2 mV at +5 V and 13.2 mV at +3.3 V. Astonishing.
...
Short circuit protection (SCP) worked fine for both +5 V and +12 V lines. It seems that over current protection (OCP) is configured with a value far above what is written on the label, as we could pull up to 44 A from the +12 V rail, while the label says the limit is 33 A.
Over load protection (OLP a.k.a. OPP) was in action, shutting down the unit if we pulled more than it could handle, preventing it from burning.
When the power supply fan is running slowly it is really quiet, but as soon as it starts spinning at its full speed noise level becomes somewhat high.
a. b- Please note that the reviewer said it's an "overload" test, not the practical maximum power drawable 24x7.
When a reviewer does an overload test, one thing is the inane curiosity of finding out what 's the max the object under test can deliver.
We all like to explore the limits of something- it's basic human nature.
But the good part in that inaneness is that it helps the reviewer and the user determine what is the "safety" margin the manufacturer slipped in to accomodate users who cut it too close to the maximum rating or even go beyond at times.
b- As said above, the true intention of a reviewer in such an extreme test, is to check if all the safety features work as claimed or not.
They risk it to provide us with assurance, not to replicate it in daily usage.
eg. We all know that automobile manufacturers crash test their vehicles.
When they say their vehicle can keep the occupants safe from severe damage, if it crashed at a certain speed maybe, i don't think they expect the buyer/user to try it out in the real-world.
d- Please observe how all the tests have been conducted and the method to load the power supply in the initial tests.
Then take note of how they have managed to overload it, especially by getting it to shut down due to overload and then reducing the amps on the 12v line, to get it to keep working without shutting down.
They have been able to spread out the power usage over the entire range of the power supply.
In real life, we may or mostly may not achieve proper/balanced loading of all rails.
Also, most components in these times primarily rely on the +12v rail.
Hence, you may have observed how the rating of power supplies these days is more focussed towards the +12v rails. Earlier we used to have power supplies with 500W or higher rating but much lesser power vaialble on the 12v rails.
Hence i feel that the value of 570W is impractical and unsafe for a normal user like us and fir all practical purposes, we shouldn't claim higher than what the factory rated specs claim.
All said, we should note that it was a "test", an overload test.
A controlled test in a controlled environment, exploring the maximum limits of a product and analysing the foolproofness of the safety features built in.
It was carried out for a short duration of time.
How the overload may have affected the components inside or the overall longetivity of that power supply is not reported/documented. ( I hope you do agree with the fact that overloading any product may drastically reduce stability/reliability/durability)
A reviewer has limited time and resources and cannot go on explaining the basics of technology or the implications of any tests, allowing a well-informed/knowledgeable user to draw his own conclusions and hopefully the correct ones.
Please do note that the reviewer has not said, and i don't think anyone will or even we should assume, that the achievements in the overload test are also achievable in 24x7/daily/normal usage, especially for a longer period of time.
We shouldn't make statements taken out of context.
For an ignorant user, that can be not only very misleading but extremely dangerous too.
p.s. On a side-note, that review was conducted in 2008 iirc.
Has anyone noticed any differences between the initial batches of VX450 sold in India and the ones sold since the last one year or so?
