Gigabyte's New Odin GT 800W Power Supply
by Christoph Katzer on July 24, 2007 12:01 AM EST- Posted in
- Cases/Cooling/PSUs
OCP Tests
In addition to transient testing, we also wanted to look at how the power supplies deal with Over Current Protection (OCP). OCP is an important safety feature that should be present on all power supplies. OCP guards the power supply and the attached components from damage that can occur when too much current is required by any of the rails. In the best case scenario, OCP should kick in and cause the power supply to simply shut down if a rail is stressed to heavily. If this doesn't happen the OPP (Over Power Protection) of our Chroma unit will kick in to save our test equipment. In a real PC, if OCP fails to work the hardware will continue to run until the cables melt, a system crash caused by out of spec voltages changes the demand on the PSU, or in the most extreme cases the power supply explodes. Needless to say, if any of the above happen there is a good chance other hardware could be damaged in the process.
Our OCP test using the Chroma equipment applies a specified amount of load to each rail of the power supply. The test always starts at no load and ends at an amount we set. The highest load always depends on the rated output from the manufacturer - enough that OCP should trigger. If OCP fails to activate, we don't need to worry since we have an OPP installed on the Chroma (and there's no PC equipment attached). We have set the step of each rising load to 2.5A, which will be added every two seconds during the test.
On the graph you will see only the 12V rails. This is because we couldn't apply any load for the OCP test to the lower rails like 3.3V and 5V. When we did so the power supply immediately shut down with no obvious reason. We had to cut the input and couldn't restart the procedure normally immediately after this occurred, so no test on these rails was possible.
As you can see we could apply a load of 24-25A on each rail. This is the usual amount of an OCP, regardless of what the label says about the rated output. There is always a little room for peak load with each power supply. Note that the load from each OCP test is applied to each rail separately. This means that if you wanted to do this test with all rails at the same time it would not be possible without greatly exceeding the rated output of the power supply. The combined power on the label states 744W, which means we could apply around 62A on all the 12V rails at the same time. Divided by four this makes around 15A per rail, which we have seen on a high static load test.
In addition to transient testing, we also wanted to look at how the power supplies deal with Over Current Protection (OCP). OCP is an important safety feature that should be present on all power supplies. OCP guards the power supply and the attached components from damage that can occur when too much current is required by any of the rails. In the best case scenario, OCP should kick in and cause the power supply to simply shut down if a rail is stressed to heavily. If this doesn't happen the OPP (Over Power Protection) of our Chroma unit will kick in to save our test equipment. In a real PC, if OCP fails to work the hardware will continue to run until the cables melt, a system crash caused by out of spec voltages changes the demand on the PSU, or in the most extreme cases the power supply explodes. Needless to say, if any of the above happen there is a good chance other hardware could be damaged in the process.
Our OCP test using the Chroma equipment applies a specified amount of load to each rail of the power supply. The test always starts at no load and ends at an amount we set. The highest load always depends on the rated output from the manufacturer - enough that OCP should trigger. If OCP fails to activate, we don't need to worry since we have an OPP installed on the Chroma (and there's no PC equipment attached). We have set the step of each rising load to 2.5A, which will be added every two seconds during the test.
On the graph you will see only the 12V rails. This is because we couldn't apply any load for the OCP test to the lower rails like 3.3V and 5V. When we did so the power supply immediately shut down with no obvious reason. We had to cut the input and couldn't restart the procedure normally immediately after this occurred, so no test on these rails was possible.
As you can see we could apply a load of 24-25A on each rail. This is the usual amount of an OCP, regardless of what the label says about the rated output. There is always a little room for peak load with each power supply. Note that the load from each OCP test is applied to each rail separately. This means that if you wanted to do this test with all rails at the same time it would not be possible without greatly exceeding the rated output of the power supply. The combined power on the label states 744W, which means we could apply around 62A on all the 12V rails at the same time. Divided by four this makes around 15A per rail, which we have seen on a high static load test.
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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.