A Look Inside
Next, we open up the power supply to take a quick look at how well things are built where it really counts. Please keep in mind that opening a PSU will void your warranty and can be dangerous.
You can see the two large transformers that supply 12V power nestled between the heat sinks. These appear to run in parallel instead of using a single large transformer. You will also notice that there are three large main capacitors in the PSU versus the normal use of two. They are Hitachi branded capacitors rated at 450v 270uF @ 105C. Yep, those are certainly Japanese capacitors. But, looking at everything else in the PSU and we see your standard Teapo capacitors. You may or may not recognize the same layout as the SilverStone OP series power supplies since Tagan looks to have sourced from the same Impervio Electronics according to the UL certification number - E311876.
Here is a look from the cable runs. The board is indeed the same one used for the 1000 Watt version. The board is marked with TG-880/1000. It seems the only difference is no cable runs attached to 12V5. This is probably a good sign for the ripple and 12V capacity as the power supply may be loping at peak claimed loads. And, like the Silverstone 1KW unit, the Tagan 1KW version can handle 80 amps of 12V load. The big difference is the rail breakdowns. The Tagan has OCP enabled on each rail while the Silverstone has it disabled for a single large rail output. So far, the Tagan is looking good.
While I am inside the power supply, I like to trace back the rail mappings to see where things are sourced. Like many power supplies, it looks like we have virtual rails shunted off the main dual 12V source. There are five in all. The power distribution is, as follows.
Now, for a couple of observations about the power distribution. First, 12V1 is dedicated to the ATX motherboard power and all of the molex and SATA power. This is a good choice since these two loads will likely never exceed 18 amps. In my testing, under load, my EVGA 790i SLI board draws about 8.5 amps and all the other items, including fans, hard drives and the like added another 7 amps. That's 15 amps.
12V2 is dedicated to the CPU and on my test system with a Q9650 at 4.0 GHz the CPU draws about 8.8 amps while running wPrime 2.0 to load each of the CPU cores at one hundred percent. So, even with two quad processors, the 18 amps should be sufficient (just) to power two. Now, just to make sure, the power supply has the second 8-pin CPU connector blended onto 12V3.
12V3 and 12V4 are dedicated PCI runs if you do not use the 8-pin CPU connector. The blue striped cables are 12V3 and the green striped ones 12V4. Each rail commands 18 amps to power up almost any two graphics cards. Like other multi-rail power supplies, there are some open questions on whether these two dedicated PCI-E outputs could handle a couple of GTX 295 or 4870X2 cards.
Well, I think we have talked enough about the Tagan TG880-U33II. We now know it is similar to the Silverstone, sourced from the same OEM and has some very good design elements. Time to torture, ahem, test the power supply.