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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Gothik - Monday, January 7, 2008 - link
hi everyone,a noob here. I was wondering whether to get this PSU for my upcoming rig. I'm gonna run a quad core q6600, 4 sticks of ddr2 RAM, and a gf 8800GT (maybe SLI later). I was wondering, if the PSU is rated at 800w like the one being reviewed, does that mean that it is powered constantly at 800w or will the mechanism in the PSU determine the actual power consumed? Also, the author mentioned that there are a few PSUs that peform equally to this unit but cost less, can I know which ones are they?
Thanx.
QueBert - Monday, July 30, 2007 - link
about to buy a new PSU, want something future proof and modular. This looks about perfect for my needs. I find it odd that my Ultra X, which is years old and was the first Modular PSU. Still has better looking cables than any other modular unit on the market. Gigabyte seemed to step up the modular appearance a bit though. Kudos to them for that.wrong - Wednesday, July 25, 2007 - link
I can think of an excellent reason to honeycomb the side wall and put a sheet of plastic in to block airflow.Weight.
Not necessarily what they had in mind, of course. But LAN boxes should be light, and this could be one way to cut weight without reducing heatsink size and compromising cooling performance or noise.
I wonder if it makes a difference to EM noise.
Bozo Galora - Wednesday, July 25, 2007 - link
I really really like the way you do these PSU reviews. Much more informative indeed than anything else on the web. I am a bit dismayed over the way AT reviewers sugarcoat conclusions on obviously poor performing equipment - tho I understand why you have to do it.Now heres a review I would like to see......
There is a just out new Coolermaster MODULAR 1000W PSU with humungous rails
http://www.rbmods.com/Bilder/Articles/Coolermaster...">http://www.rbmods.com/Bilder/Articles/Coolermaster...
Heres the first review.......
http://www.rbmods.com/Articles/Coolermaster/Rs-a00...">http://www.rbmods.com/Articles/Coolermaster/Rs-a00...
This is the new esba model, NOT the current emba
Note in the review are the usual stupid useless graphs showing "rock solid" unchanging rails. Since I am about to buy, I would love to see how your review compares. And this is modular so it might help in your investigation of this modality.
Keep on truckin'
erikpurne - Tuesday, July 24, 2007 - link
Totally agree. It would be much easier to see where your system typically falls on the efficiency graph.
Also, on the 'Power Loss' graphs, the upper line should be input, and the lower one output. Oh, and watts are power, not energy!
Myrandex - Tuesday, July 24, 2007 - link
You should pictures of the LEDs, but there should have been a lights out LEDs enabled pic :)Good article though, and the build quality looked fantastic
the goat - Tuesday, July 24, 2007 - link
I assume that the software is only for windows? Of course the power supply will operate without the software but it would be nice to use the product to it's full potential with any operating system. In future articles please tell us if there is software for linux or not.Vidmar - Tuesday, July 24, 2007 - link
While I think the Efficiency charts in load percentage are nice, if you included Efficiency charts in watts it would be more informative from a buying perspective.The reason? I know the sum of system load is 375watts normally. The way it is now, if power supply XYZ has a max load of 650watts, I have to calculate where my ~375watts falls into that load chart (~57% load). But if the next power supply has 1000 watts max, then I have to yet again calculate what load percentage that may be for *that* power supply. If the Efficiency charts were in watts, instead of load, no calculations would be necessary. If I could look at your charts and see that XYZ power supply provided those watts the most efficiently, that would be the power supply I would get.
Maybe you could just provide a second X axis on the chart that included the watts.
Thanks!
MadBoris - Tuesday, July 24, 2007 - link
I really like the software component possibilities, looks like it needs some tweaking though like with 18a max per rail.As to memory and CPU usage, well that is .Net for you, that footprint problem is here to stay. Thx to MS.
I'm a little curious to the max 25a per rail.
Nvidia states 8800 GTX should have 30a http://nvidia.custhelp.com/cgi-bin/nvidia.cfg/php/...">Link
Maybe someone can clarify the real draw of an 8800 GTX and is 25a completely sufficient.
What about next gen?
Good review, looking forward to more like it.
As cool as this PSU is, $200+ is a bit too much for a PSU.
Christoph Katzer - Tuesday, July 24, 2007 - link
Depends on how much your graphics card needs to work. When your display just has 1024pxl in width you can run the 8800 in a decent system with a 300w psu. If you are using a 30" screen with 2560pxl in width it is a total different story. But don't worry, we are working on an article to make things like that very clear.