New build advice

[ik9000]

phew <breathes huge sigh of relief>

[Pob255]

@ik9000
I'm afraid you cannot just look at those charts and say the HX is louder, there is no fixed standard for dBa measurement and the numbers can be greatly skewed by many factors within the testing method and environment the tests are taken under.
So you can only compare noise test results if they are carried out under the same methodology in the same environment (ie by the same people in the same testing facility)

So you can say from those graphs that the 750 HALE is quieter than the 850 hale, as both are made by the same company for the same company we can fairly safely assume the testing was the same.
We can also say the both the HALE units start to increase their sound levels before the HX does
but that's about as far as we can go.

On the efficiency numbers the HX is tested at 50c ambient which is far higher than the 23c ambient that 80plus is offically done at.
I seem to remember that the HX could score higher and actually just get silver if if corsair allowed the tests to be run at 23c

Not saying the HALE is bad, far from it, just the HK is no slouch ether.
Just beware of comparing numbers from different sources.

If you really want to push the boat out then go for the seasonic X psu http://www.scan.co.uk/products/660w-...ssfire-eps-12v probably the best psu in the 600-700w rating

[ik9000]

@ik9000
I'm afraid you cannot just look at those charts and say the HX is louder, there is no fixed standard for dBa measurement and the numbers can be greatly skewed by many factors within the testing method and environment the tests are taken under.
So you can only compare noise test results if they are carried out under the same methodology in the same environment (ie by the same people in the same testing facility)

So you can say from those graphs that the 750 HALE is quieter than the 850 hale, as both are made by the same company for the same company we can fairly safely assume the testing was the same.
We can also say the both the HALE units start to increase their sound levels before the HX does
but that's about as far as we can go.

On the efficiency numbers the HX is tested at 50c ambient which is far higher than the 23c ambient that 80plus is offically done at.
I seem to remember that the HX could score higher and actually just get silver if if corsair allowed the tests to be run at 23c

Not saying the HALE is bad, far from it, just the HK is no slouch ether.
Just beware of comparing numbers from different sources.

If you really want to push the boat out then go for the seasonic X psu http://www.scan.co.uk/products/660w-...ssfire-eps-12v probably the best psu in the 600-700w rating

Regarding the comments on efficiencies:

from the 80plus test procedure:

http://efficientpowersupplies.epri.c...tocol_R6.5.pdf

5.6 Test Room
As is specified in IEC 62301, the tests shall be carried out in a room that has an air speed close to
the UUT of <= 0.5 m/s, and the ambient temperature shall be maintained at 23°C ± 5°C
throughout the test. There shall be no intentional cooling of the UUT by use of separately
powered fans, air conditioners, or heat sinks. The UUT shall be tested on a thermally nonconductive
surface.

5.7 Warm-up Time
Internal temperature of the components in a power supply could impact the efficiency of the unit.
As a general recommendation before testing, each UUT shall be loaded up to the test load for a
period of at least 15 minutes or for a period sufficient that the total input power reading over two
consecutive five-minute intervals does not change by more than ± 0.2%.

so it is the efficiency measured on tests at 23C +/- 5C that is stated on the efficiency charts. This is a requirement of the 80plus test procedure. The corsair HX650w is only bronze rated, and this rating is at 23C +/- 5C.

Corsair state that their power supply will deliver its full power at temperatures up to 50C. This is not the same as saying that it will maintain its efficiency at 50C. Resistance, resistivity, impedance etc increase with temperature, and efficiency therefore decreases with increasing temperature. A power supply achieving only a bronze rating at 23C would likely get a worse rating at 50C due to the greater losses at this temperature. This is the reason the 80plus tests specify the temperature at which the rating tests are undertaken - to allow direct comparison between different PSUs.

650W PSU @ 81% efficiency (80plus bronze rating under 100% load) is drawing 802W from the mains at 23C. At 50C to maintain delivery of the full power this 650W PSU will have to draw greater power from the mains since it won't be as efficient at converting the AC mains to DC at this higher temperature.

Most good PSU manufacturers certify that the PSU wattage stated is for full load under continuous use - and the temperatures that go with this - and not simply a peak value. This includes NZXT.

This latter point is well worth remembering if looking at budget PSUs since some claim power values that are actually only peak values - and the PSU cannot deliver this load continuously which could give stability problems if the user is running the PSU at high loads.

Regarding noise:

dBa is noise measured using the a weighting filter which is a standard frequency weighting. You're right in that tests which don't use exactly the same set-up are always going to be more difficult to compare and the methods used probably aren't going to be done the same way by two different manufacturers. I can however say is the 750w Hale is very quiet in use, as I own and use that one. I'll look at the noise stuff more tomorrow - I'm falling asleep typing this.