Tagan TurboJet TG1100-U95 1,100 W Power Supply
By Gabriel Torres on December 2, 2006
With AMD’s Quad FX platform now available – featuring two dual-core Athlon 64 FX CPUs, up to four video cards and up to 12 hard disk drives – power supplies reaching 1,000 W may become more and more common among very high-end gamers. Tagan fills this space with its TurboJet TG1100-U95, a 1,100 W power supply that has a terrific aesthetics. We completely disassembled this beast to see if what was inside the box was on the same level of what was outside. Read on.
The presentation of this product is really impressive. It comes in a very good-looking high-quality leather case, which you can definitely use for a different purpose after you install the power supply on your system – for instance, you can use it as fancy toolbox.
On Figures 2 and 3 you have an overall look of TurboJet TG1100-U95.
It is a high-end power supply with active PFC. Instead of having a big 120 mm fan on its bottom it has two 80 mm fans, one at its front and the other at its back. We prefer the 120 mm fan approach, as it provides a better airflow with lower noise level. This power supply has the same size as a conventional ATX power supply, which drew our attention, as Galaxy 1000 W from Enermax had to be bigger in order to accommodate all necessary components to deliver true 1,000 W of power – and this model from Tagan is labeled 1,100 W. This gave us a hint that we needed to take a careful look at its internal design.
As you can see in Figure 3, this power supply does not have a modular cabling system, and this is one of the major flaws of this power supply, and we will explain why in just a few moments.
This power supply comes with four independent auxiliary PCI Express power cables for feeding up to four video cards. These cables use a top-notch rigid rounded sleeving with a ferrite bead at one of the ends (this component works as a filter), which is great. What immediately caught our eye was that these cables are identical to the ones used by OCZ ModStream 520 W, so this gave us a clue that the real manufacturer of this Tagan power supply could be the same real manufacturer of OCZ ModStream 520 W (and in fact it is: Topower).
There is a colored sticker on each ferrite bead identifying each cable: PCIE-1 through PCIE-4. The connectors used are also top notch, very different from the standard connector.
One problem with this power supply is that unless you have four video cards on your system, you will have unused auxiliary PCI Express cables hanging inside your PC, blocking the airflow. If this power supply used a modular cabling system, you could simply remove the unused cables.
There are three other cables using the same rigid rounded sleeving with a ferrite bead, the ATX12V connector, the EPS12V connector and one standard peripheral connector. They also use better connectors compared to the standard connector used by other power supplies.
This power supply comes with an external ground cable (using a thick 12 AWG wire and a gold-plated terminal), for you to connect it to the metallic chassis from your case. This is the first power supply we’ve seen coming with this feature. Inside the power supply this cable is connected to the DC ground, i.e., connected together with all black wires used by the power supply cables.
The AC power cord has gold-plated terminals, a really fancy feature. It also has a ferrite bead, which works as a filtering device.
Tagan TG1100-U95 uses a 24-pin motherboard connector that can be transformed into a 20-pin one, see Figure 10. This main motherboard cable uses 16 AWG wires (the wires used by the standard peripheral cables are thinner, 18 AWG).
This power supply comes with four adapters that allow you to convert any Serial ATA power connector into a standard peripheral power connector. This is the first time we saw this feature.
This power supply comes with nine peripheral power cables: four PCI Express auxiliary power cables, one “special” standard peripheral cable with just one connector, two Serial ATA power cables with three SATA power connectors each, one Serial ATA power cable with four SATA power connectors and one peripheral power cable with three standard peripheral connectors. This power supply also comes with one “Y” cable for converting one standard peripheral connector into two floppy disk drive power connectors. It also comes with four adapters that convert the SATA power connectors into standard peripheral connectors, as mentioned earlier.
We decided to fully disassemble this power supply to take a look inside and see if its internal design was on the same level as its external design.
We decided to disassemble this power supply to see what it looks like inside, how it is designed, and what components are used. Please read our Anatomy of Switching Power Supplies tutorial to understand how a power supply works inside and to compare this power supply to others.
In this page, we will have an overall look, while in the next page we will discuss in details the quality and rating of the components used.
We can point out several differences between this power supply and a low-end (a.k.a. “generic”) one: the construction quality of the printed circuit board (PCB); the use of more components on the transient filtering stage; the active PFC circuitry; the power rating of all components; the design; etcetera.
The first thing that caught our eye was the use of two main transformers instead of just one. So far we’ve seen only another power supply using two transformers, and that was Galaxy 1000 W from Enermax. Tagan TurboJet TG1100-U95 transformers, however, are connected using a different circuit design, as we will discuss in a more appropriate moment.
As we mentioned on other articles, the first place we look when opening a power supply for a hint about its quality, is its filtering stage. The recommended components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components than that, usually removing the MOV, which is essential for cutting spikes coming from the power grid, and the first coil.
This power supply uses more components than the minimum recommended: three ferrite coils, four Y capacitors, two X capacitors and one MOV (see Figure 17). As the MOV was hidden between the rectifying bridges, the PFC electrolytic capacitor and one of the ferrite coils, we took another picture from this component after we removed the electrolytic capacitors and the rectifying bridges, see Figure 18. Before the standard transient filtering stage there are two ceramic capacitors connected in series with the main AC power wires, which is unusual, as they are not using “X” or “Y” configurations (on these two configuration the capacitors are connected in parallel with the main AC power wires, not in series).
Now let’s have a more detailed discussion regarding the components and design used on Tagan TurboJet TG1100-U95.
We were very curious to check what components were chosen for the power section of this power supply and also how they were set together, i.e., the design used. We were willing to see if the components could really deliver the power announced by Tagan – especially because we are talking about a power supply labeled over 1,000 watts.
For a better understanding of what we are talking here, please read our Anatomy of Switching Power Supplies tutorial.
This power supply uses two GBU1006 rectifying bridges in its primary stage, which can deliver up to 10 A each (rated at 100° C), so the total current the rectifying section of this power supply can handle is of 20 A. This is more than adequate rating for a 1,000 W power supply. The reason why is that at 115 V this unit would be able to pull up to 2,300 W from the power grid; assuming 80% efficiency, the bridge would allow this unit to deliver up to 1,840 W without burning this component. Of course we are only talking about this component and the real limit will depend on all other components from the power supply. Just for a comparison, Enermax Galaxy 1000 W uses two 20 A bridges, meaning it can handle the double: 40 A.
The active PFC circuit from this power supply uses three power MOSFET transistors (20N60C3 – the same one used by several other power supplies we took a look, like Antec Neo 550 HE, Cooler Master iGreen Power 430 W, Corsair HX620W, Thermaltake Toughpower 750 W, OCZ GameXstream 700 W and Zalman ZM600-HP). This power supply from Tagan, Zalman ZM600-HP and OCZ GameXstream 700 W are the only three power supplies we’ve seen using such design. All other high-end power supplies we’ve seen to date use only two transistors (except Enermax Galaxy 1000 W, which uses four transistors). Each 20N60C3 can handle up 300 A @ 25° C each in pulse mode (which is the case).
Instead of using only one electrolytic capacitor on its active PFC circuit, this power uses two 1,200 µF x 200 V connected in series, which equals to a 600 µF x 400 V capacitor. When two identical capacitors are connected in series, their capacitance is halved, but the voltage limit is doubled. This is a common trick used to reduce the space needed inside the power supply, as capacitors with higher voltages are physically bigger. The electrolytic capacitors used here are from Toshin Kogyo (TK) – even tough this brand is Japanese, their capacitors are rebranded OST (Taiwanese) components – and the electrolytic capacitors found on the secondary are also Taiwanese, from Teapo.
The active PFC components (PFC coil, PFC diode and NTC thermistor) from this power supply are placed in a different order compared to the most usual configuration. In order to clarify this, we drew the schematics of this power supply active PFC circuit and compare it to the most common design in Figure 19.
This power supply uses four 20N60C3 power MOSFET transistors on its switching section, the same type used on the active PFC circuit. Without looking to this power supply circuit, we though that Tagan used the same design Enermax did on their Galaxy 1000 W: two transistors driving each transformer, making two completely separated primary and secondary circuits. However, on Tagan TurboJet TG1100-U95 there is only one switcher. Even tough there are four transistors, two of them are connected in parallel to the other two just to increase the current/power this single switcher can deliver (the design of the switcher, by the way, is two-transistor forward).
On Figures 20 and 21 you can see the components that are attached to the primary heatsink. As mentioned, even though there are four power MOSFET transistors (labeled Q4 through Q7), Q4 and Q5 are connected in parallel, as it is Q6 and Q7.
For a better understanding of what we are going to explain, we drew a simple block diagram of what we think would be a good design for a 1,000 W+ power supply (in fact, the same design used by Enermax Galaxy 1000 W) and the design used by Tagan TurboJet 1100 W. Please pay careful attention in Figure 22.
On our recommended design, there are two complete independent primary and secondary circuits, as if there were two complete power supplies inside the unit housing. In fact the only thing these two circuits share are the +Bus and –Bus power lines coming from the active PFC circuit.
So even though this power supply from Tagan has two transformers, they are not independent, as the same transistors drive them.
The primary is controlled by one CM6800 integrated circuit, which is an active PFC and PWM controller combo. It is located on a small printed circuit board shown in Figure 23. This is the same controller used by several other power supplies, like OCZ GameXstream 700 W, Zalman ZM600-HP, Antec Neo HE 550 and Thermaltake Toughpower 750 W, just to name a few.
Even though this power supply has two transformers, the output of all +12 V rectifiers are connected together.
The +12 V output uses all the four 63CPQ100 Schottky rectifiers. Two of them are connected to one transformer and the other two are connected to the other transformer, however the outputs of all four rectifiers are connected together. The maximum theoretical current the +12 V line can deliver is given by the formula I / (1 - D), where D is the duty cycle used and I is the maximum current supported by the rectifying diode (which in this case is made by four 30 A diodes, two of them connected, in parallel, to the first transformer, and another two connected, in parallel, to the second transformer). Just as an exercise, we can assume a typical duty cycle of 30%. This would give us a maximum theoretical current of 171 A or 2,057 W for the +12 V output. The maximum current this line can really deliver will depend on other components, in particular the coil used. This output is clearly overspec'ed.
For the +5 V output two 40CTQ045 are used. The maximum theoretical current the +5 V line can deliver is given by the formula I / (1 - D), where D is the duty cycle used and I is the maximum current supported by the rectifying diode (which in this case is made by two 20 A diodes in parallel). Just as an exercise, we can assume a typical duty cycle of 30%. This would give us a maximum theoretical current of 57 A or 286 W for the +5 V output. The maximum current this line can really deliver will depend on other components, in particular the coil used.
The +3.3 V output also uses two 40CTQ045 Schottky rectifiers, connected to a dedicated transformer output, which is terrific. On the vast majority of power supplies even when the +3.3 V output has its own rectifiers, they are connected to the same transformer output as the +5 V line, so the transformer limits the maximum current (and thus power) the +5 V and +3.3 V lines can deliver together (a concept called “combined power”). Using the same math the +3.3 V output would be capable of delivering up to 189 W. Like we said before, the other components used on the power supply will limit the maximum current and power this output can actually deliver.
On the pictures below you can see the rectifiers used on this power supply secondary.
In Figure 26, you can see the thermal sensor from this power supply, in charge of changing the speed of the fans according to the power supply internal temperature. Usually this component is found attached directly to the secondary heatsink or right below it, but on this power supply it is located inside the +12 V coil.
In Figure 27, you can see Tagan TurboJet TG1100-U95 label stating all its power specs.
As you can see this power supply has four virtual +12 V rails.
From the previous page we came with some maximum theoretical numbers for the +12V output (2,057 W), +5 V (286 W) and +3.3 V (189 W).
As we mentioned earlier the maximum current/power each line can really deliver will depend on other components, especially the transformer, the coil, the wire gauge and even the width of the printed circuit board traces used.
For the +12 V output Tagan stated 20 A for each one of the power supply four virtual rails – Enermax states 17 A for each +12 V rail on its Galaxy 1000 W, however Galaxy has five rails. This would give a 240 W maximum per rail or 960 W maximum total – the number labeled by Tagan.
For the + 5 V output Tagan stated a 28 A maximum current (Galaxy 1000 W is labeled as 30 A), which translates to 140 W, while for the +3.3 V output the manufacturer also stated a 28 A maximum current (Galaxy 1000 W is labeled as 30 A), or 92.4 W. On the label, however, Tagan says that the combined power of +3.3 V and +5 V outputs is of 180 W, which is rather strange, as this two outputs use two separated circuits (they use the same switching section, though).
All positive outputs are labeled with a current well below the maximum current each rectifier can deliver, but as we mentioned several times, the maximum current/power will depend on other components, as all rectifiers are overspec’ed.
Unfortunately we don’t have the necessary equipment to make a true power supply review; we would need to create a real 1,100 W load with a load tester to check if this power supply could deliver its labeled power or not. Our friends at Planet3Dnow.de have one and their Tagan TG1100-U95 burned when they tried to pull more than 768 W @ 25° C on the +12 V lines.
Also, as a final note, Tagan doesn’t specify the temperature under which the power supply is rated. Usually when no temperature is stated, the manufacturers assume 25° C, which is a temperature far below the power supply real working temperature. Keep in mind that the maximum power a power supply can deliver drops as its internal temperature increases. Here it is important to notice that Galaxy 1000 W from Enermax is rated at 50° C and also according to our friends at Planet3Dnow.de, it can really deliver its announced power.
Tagan TG1100-U95 power supply specs include:
* Price supplied by the manufacturer.
We think that this would be a better product if internally the manufacturer added two truly independent circuits. This power supply shares the same switching section between the two transformers and the same secondary filters for the +12 V outputs coming from the two transformers.
It wouldn’t cost much to correct this power supply design, especially when you think about its price tag – USD 350 in the USA. What? Wait a moment. Enermax Galaxy 1000 W costs almost the same thing (in some stores you may find it being sold by only USD 10 or USD 20 more) and has the perfect design for a 1,000 W power supply: two completely independent circuits inside the box and what is more important, the capacity of truly delivering 1,000 W at 50° C.
Tagan TurboJet 1100 W is labeled at 25° C and our friends at Planet3Dnow.de couldn’t pull more than 768 W from the +12 V lines (which are labeled 960 W) even at 25° C. What a bummer!
Internally Galaxy 1000 W uses more and better components: its rectifying bridges can handle double the current compared to Tagan’s and it uses four transistors on its active PFC circuit (Tagan’s uses three), not to mention the whole second +12 V filtering circuit, not available on Tagan’s. So Tagan pricing is completely insane.
Another thing Tagan should do is correct their website, manuals and boxes. They don’t announce all technical specs from their products. For this model in particular, there is no data sheet available (the available datasheet if for the U96 model, which carries six +12 V virtual rails) and we couldn’t find anywhere details about this power supply efficiency and protections.
Even its terrific external presentation has its flaws, and you would learn them only when trying to assemble a high-end system. The absence of a modular cabling system is critical: the cables with the special shielding are very stiff and also unused cables will block the PC internal airflow – since these cables are really thick this can be a real problem.