Gigabyte's New Odin GT 800W Power Supply
by Christoph Katzer on July 24, 2007 12:01 AM EST- Posted in
- Cases/Cooling/PSUs
Dynamic Testing
As our latest addition we will now perform dynamic tests on our test power supplies. During normal tests, we use a constant current to bring them to a certain level of load. The load is also constant once we reach that level, which is not necessarily the same as in a normal PC environment. The load generated by a PC is dynamic and can be higher or lower depending on the applications being run. A hard disk for example will suddenly apply a much higher load during startup, as it attempts to bring the platter RPMs up to speed. The more hard disks you have, the higher the startup load will be. These increased loads not only occur at startup but throughout normal usage, and depending on the component generating the load the demands can come on any or all of the rails.
High transient loads (i.e. short spikes of higher power requirements) can be harmful for a power supply and result in the system restarting/rebooting on occasion or sometimes even in damage to the power supply or connected components. The latest Power Supply Design Guide addresses this problem by defining how much transient load should be allowable on any of the rails. Even with high transient loads, the voltages should still stay within the normal specified range.
With the Chroma test equipment we can apply a very accurate load to the various rails, and in addition we can specify the duration of loading a specified value. This allows us to apply a different load with a different duration for each rail. This is important since there are clear specification differences between each rail. Since the maximum step size for the transient load is rated off the actual performance of each power supply, we have to apply a different transient load level to each new unit that we test.
The transient load will be applied on different stages of constant loading. We felt that testing transient loads at 20%, 50%, and 80% load would be the best way to clearly show meaningful results. The tests will be performed with each of the three different input voltages of 90/100, 115 and 230VAC.
The Gigabyte Odin GT performed very well during our dynamic load tests and was not disturbed by any transient loads. Even an inrush current caused by going from off state to 100% load didn't cause any problems.
As our latest addition we will now perform dynamic tests on our test power supplies. During normal tests, we use a constant current to bring them to a certain level of load. The load is also constant once we reach that level, which is not necessarily the same as in a normal PC environment. The load generated by a PC is dynamic and can be higher or lower depending on the applications being run. A hard disk for example will suddenly apply a much higher load during startup, as it attempts to bring the platter RPMs up to speed. The more hard disks you have, the higher the startup load will be. These increased loads not only occur at startup but throughout normal usage, and depending on the component generating the load the demands can come on any or all of the rails.
High transient loads (i.e. short spikes of higher power requirements) can be harmful for a power supply and result in the system restarting/rebooting on occasion or sometimes even in damage to the power supply or connected components. The latest Power Supply Design Guide addresses this problem by defining how much transient load should be allowable on any of the rails. Even with high transient loads, the voltages should still stay within the normal specified range.
| Dynamic Testing | ||
| Output | Maximum Step Size (% of rated output amps) |
Maximum Step Size |
| +12V1 | 40% | - |
| +12V2 | 60% | - |
| +5V | 30% | - |
| +3.3V | 30% | - |
| -12V | - | 0.1 |
| +5Vsb | - | 0.5 |
With the Chroma test equipment we can apply a very accurate load to the various rails, and in addition we can specify the duration of loading a specified value. This allows us to apply a different load with a different duration for each rail. This is important since there are clear specification differences between each rail. Since the maximum step size for the transient load is rated off the actual performance of each power supply, we have to apply a different transient load level to each new unit that we test.
The transient load will be applied on different stages of constant loading. We felt that testing transient loads at 20%, 50%, and 80% load would be the best way to clearly show meaningful results. The tests will be performed with each of the three different input voltages of 90/100, 115 and 230VAC.
The Gigabyte Odin GT performed very well during our dynamic load tests and was not disturbed by any transient loads. Even an inrush current caused by going from off state to 100% load didn't cause any problems.
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strikeback03 - Tuesday, July 24, 2007 - link
Does the software need to be running for the voltage regulation to work? Or can you make changes then close the software and have the changes still work on the PSU?Also I'd guess if UV lighting is that useful for a case you could swap the blue LEDs for some UV ones - looks like enough wire is exposed to cut the blue ones and solder in UV ones.
Oberst - Tuesday, July 24, 2007 - link
Hello,nice review (i wouldn't expect anything else of you). But I've got a question about the measuring-software: Was it reliable, when measuring voltages? You already mentioned, that the wattage was not reliable. So I'd like to know, if that was because of wrong measured amps or volts.
greets Oberst.
Christoph Katzer - Tuesday, July 24, 2007 - link
Voltages have been quite accurate; amps have been wrong in almost every case.qpwoei - Tuesday, July 24, 2007 - link
Once you've got the ripple measurements sorted out, it'd be nice to get some scope traces as the load changes. Poor transient response of the rails can cause all sorts of hard-to-diagnose problems in the real world.Christoph Katzer - Tuesday, July 24, 2007 - link
We use a scope to follow response on the rails but until now we feel the data is not good enough to present. If there would be something to extraordinary to tell we surely would.bob4432 - Tuesday, July 24, 2007 - link
what about that? a good quality unit, the Corsair 520HX seems to be a lot of people's favorite lately, how does it really stack up? or some of the FSP "Green" units - are they really that efficient? what about seasonic - really as good as everyone says?these reports are all fine and dandy, but you are catering to possibly 5% of your user base, yes even here 800W is extreme overkill.
and it is not a $$$ issue but rather a reality issue. i am surprised you guys testing these are continuing the thought process by only reviewing the upper wattage units and thus making everyone think they need one when they don't - people on review 750W psus, so i must need one...come on guys
Christoph Katzer - Tuesday, July 24, 2007 - link
Will come. No worries about that. At the moment we are just starting as you can see and of course every company wants to have the best PSU tested first. We'll have lower ones very soon but need to work on that mountain of PSUs here first. With 380w you will see a Seasonic pretty soon for example.bob4432 - Tuesday, July 24, 2007 - link
will definitely be looking forward to them :)ATWindsor - Tuesday, July 24, 2007 - link
I disagree that an OCP per rail i s a good thing, it onyl makes using the PSU more of a hassle, since you can draw a lot less from the PSU on 12V than the specs would make possible, if you are unlucky and draw most of it from one rail. Several manufacturers have one big rail without any know safety-problems, having an OCP for the combined drav from the 12V-lines however is a good thing.AtW
dare2savefreedom - Tuesday, July 24, 2007 - link
I would be interested in knowing how a psu runs with dual 8800gtxs in virginia in summertime in an old house with a window air conditioner.Not these theoretical white glove clean room lab environment tests.
triple sli 8800gtx?
come one stop playing with your iphone.