by Oleg Artamonov
03/04/2010 | 03:20 PM
About one year ago we reviewed a few power supplies from Chieftec but the newer A135 series (its models have names like APS-xxxS and APS-xxxC) had not made it into our labs back then. We’ll cover it now. Besides, we will discuss the Chieftec CFT-600-14CS model which has an extra letter in its name compared to the previously tested products. So, we will also explain you the difference between the CFT-xxx-14CS and the CFT-xxx-14C power supplies.
Click the following link for a description of our testing methodology and equipment and a brief explanation of what the specified and tested parameters of power supplies mean: X-bit Labs Presents: Power Supply Units Testing Methodology In-Depth. If you feel overwhelmed with the numbers and terms this review abounds in, refer to an appropriate section of the mentioned article for explanation.
You can also go to our Cooling/PSU section to check out reviews of all other PSU models we have tested in our labs.
We will mark the actual power consumption of three system configurations (discussed in our article PC Power Consumption: How Many Watts Do We Need?) in the cross-load diagrams. This will help you see if the PSU can meet the requirements of a real-life PC.
The first product to be discussed in this review represents the A135 series which includes power supplies ranging from 350 to 850 watts. It splits up into two partially overlapping subseries: one going from 350 to 550 watts and another from 500 to 850 watts.
The PSU comes in a small cardboard box. The text on the box enumerates various benefits of this power supply but fails to mention any specific characteristics.
The UL certificate number of E320351 indicates that this power supply was manufactured for Chieftec by Sirfa whose products have already been tested in our labs. If this name does not ring any bells with you, I can inform you that Sirfa was founded two years ago out of a Sirtec fab. And Sirtec itself should be familiar to you by our PSU reviews.
The PSU has a plain gray case of a nearly standard size. It is 160 millimeters long, making it possible to install a 140mm fan. Take note of the shape of the case around the fan: Chieftec seems to have adopted Enermax’s idea of making the gap between the case and the fan smaller in order to lower the latter’s noise (by a couple of decibels, according to Enermax).
You can see a typical layout of a modern PSU inside: the power components reside on three heatsinks which are simple smooth aluminum bars. This should be enough for cooling considering the high efficiency and low power dissipation of the PSU’s electronics. The PFC device is active. There is no dedicated voltage regulation here.
The PSU uses Teapo capacitors which enjoy a good reputation, so you can expect a long service life from it. The quality of assembly and soldering is overall good.
The PSU has the following cables and connectors:
I have some critical remarks about this selection of cables and connectors. There is no second graphics card connector although the PSU can easily power up senior graphics cards with two power plugs. And the cables are rather short. They may prove not long enough to connect HDDs in a large computer case. In system cases with a bottom PSU compartment which are becoming more and more popular, the CPU cable is going to be almost certainly too short.
The PSU is rated for an output power up to 550 watts and can yield up to 450 watts across its +12V rail. Thus, its effective output power (i.e. what you can get from it in a real computer that consumes mostly from the +12V power rail) is about 500 watts, which is good. The +12V rail is split into two “virtual” lines, 25 amperes each.
The APS-550S delivers stable voltages, especially considering that it lacks dedicated voltage regulation. In fact, the voltages only go out of the prescribed limits when the total load is highly misbalanced towards the +5V and +3.3V rails, which just cannot occur in a real computer. Our reference configurations (marked with the crosses in the diagram) are within the green zone, meaning that the output voltages deflect no more than 3% from the required levels.
The output voltage ripple at full load is slightly above the allowable limit on the +5V rail, but you should not worry about those individual short spikes shooting above the 50-millivolt line. They are not going to affect your computer’s stability. The other two rails are all right in this test, too.
This PSU is cooled by a Globe Fan RL4Z S1352512H which is partially covered with a piece of film in order to drive the air into the back of the PSU. Thus, the entire volume of the PSU case is going to be ventilated well.
The fan is rotating at less than 700 RPM under low loads and is virtually silent then. At loads above 200 watts, the fan’s speed grows up linearly, making it audible at loads of 300-350 watts. The maximum speed of the fan is 1430 RPM but the noise remains acceptable even then.
Together with my UPS (the APC SmartUPS SC 620 model) this power supply worked at loads up to 362 watts when the two were powered from the mains, but when they switched to the UPS’s batteries, the UPS would shut down in a couple of seconds at a load of 350 watts and in 5 to 7 seconds at a load of 300 watts. Thus, this PSU has poor compatibility with uninterruptible power supplies. I recommend you to use an UPS with a high reserve of wattage or a sinusoidal output voltage with this PSU.
The PSU has a good but not record-breaking efficiency of 85-86%. It is good that the efficiency does not depend much on the load, falling below 83% at loads of 60 watts only.
The standby source is rated for a current of 2.5 amperes and copes with its job just fine. Its voltage is just a little lower than the required 5 volts at full load.
The only thing I can really find fault with in the Chieftec APS-550S is that its cables are rather short. There is no more than 42 centimeters from the PSU case to the first connector, which may be a problem for large system cases. However, if you’ve got a small system case, the APS-550S will be a good choice as it is a neat, stable, quiet and rather inexpensive power supply.
I have already tested Chieftec’s PSUs with very similar names: the model name just lacked the letter S at the end. The single difference in the official descriptions is that the 14CS series is not declared to comply with the 80+Plus standard which defines the bottom limit of efficiency.
This product comes in a medium-sized box. Like with the other products from Chieftec, the text on the box tells you about the various benefits of the PSU but does not mention any of its specific characteristics.
The PSU case is black and 160 millimeters long.
Removing the cover, I saw the PSH platform from Channel Well which had come to our labs under so many names like Chieftec (the Turbo Series CFT-xxx-14C units were based on it, too), Thermaltake, Corsair, Xigmatek, etc.
I can understand the manufacturers’ predilection towards this platform. It is a well-designed modern power supply with active PFC and dedicated voltage regulation. It is stable and reliable as you will see below. My visual inspection revealed no quality related issues.
Like in the APS series, this PSU is equipped with good electrolytic capacitors from Teapo.
The Chieftec CFT-600-14CS has modular cables that are most handy when you are assembling your computer in a cramped system case where it’s difficult to hide the huge bunch of unused cables. The connectors are Molex Mini-Fit Jr. They differ in shape and color depending on what cables they are meant for.
The designations V1, V2, etc indicate what exactly +12V line goes to particular connectors. It is somewhat odd that the CPU has two such lines whereas the two graphics cards cables have only one because modern graphics cards consume far more than CPUs. You may find yourself in a stupid situation with a monstrous card like GeForce GTX 295: when under load, it won’t be satisfied with the 18 amperes available with the two default cables, and you will have to use an adapter to connect one of the card’s power plugs to a Molex connector of the PSU. People at Chieftec must have thought that owners of such premium-class graphics cards would prefer higher-wattage PSUs although 600 watts should be quite enough for a serious gaming computer.
The PSU has the following cables and connectors:
Included with the PSU are:
Like with the previous model, I have a reason to complain about the length of the cables. Being modular, they can as well be long, up to 60 centimeters, to avoid any problems even in very large system cases. Two SATA and two PATA cables are included into the box, so connecting four modern HDDs is going to be inconvenient because one SATA cable will go to the DVD drive, which is usually far from HDDs, and the other one has only three connectors.
Save for these cavils, the selection of cables is all right and most users are going to be perfectly satisfied with it.
The PSU can yield nearly all of its output power via the +12V rail split up into four “virtual” lines, 18 amperes each. As I’ve said above, the lines are not distributed optimally among the connectors: two for the CPU and one for graphics cards. It would be better to either increase the current to 22-25 amperes or allot two lines to graphics cards as well. This would help avoid the situation when a top-end graphics card won’t be satisfied with 18 amperes, making the user connect it to the PSU via an adapter.
The voltages boast ideal stability. The voltage on the +12V power rail is within a 1% deflection from the required level. The rest of the rails deflect no more than 3%. That’s a perfect result.
The output voltage ripple is within the required limits at maximum load.
The PSU is cooled by a 140mm fan from Yate Loon which is half-covered by a piece of plastic.
The fan starts out at 1000 RPM and works at this speed until a load of 300 watts with something. Its airflow is audible but comfortable. Thus, the CFT-600-14CS is not really silent, but quiet. At loads of 500W and higher the PSU becomes loud.
Together with an APC SmartUPS SC 620, this power supply was stable at loads up to 370 watts when powered from both the mains and the batteries. The pair switched to the batteries without problems and the UPS was stable.
Despite the lack of an 80+Plus badge on the label, the efficiency is over 80% throughout a wide range of loads (at least in the 220V power grid). The peak efficiency is 86%.
The standby source is rated for a current of 3 amperes and copes with that load easily.
Compared to the APS-550S, the CFT-600-14CS has a higher wattage rating and three more benefits, namely more stable output voltages, compatibility with UPSes, and modular cables. The first benefit is insignificant, however, because the output voltages of the APS-550S do not deflect more than 3% under loads typical of modern computers, either.
The APS-550S, in its turn, is quieter and cheaper.
Comparing the CFT-600-14CS and CFT-600-14C, I can find no difference between them from an end-user’s point of view.
The last product in this review belongs to the A135 series but differs from the above-discussed APS-550S not only with its wattage rating but also with the letter C at the end of the model name. What’s the practical difference then?
The PSU comes in a medium-sized box designed in Chieftec’s unified style.
As opposed to the gray APS-550S, the APS-750C is painted matte black. There are no other visual differences, except for the On/Off switch.
The interior is completely different, though. There are no similarities with the APS-550S. The component layout is different and the heatsinks are larger. This PSU has dedicated voltage regulation and there is a card with connectors for modular cables at the back. The real manufacturer of the PSU is the same, however. It is Sirfa.
The four connectors for graphics cards made it necessary for the manufacturer to allot two +12V lines to them in order to ensure sufficient load capacity. If you’ve got one top-end graphics card (a dual-processor one, for example), you should connect one of its power plugs to V3 and another to V4. This will help you avoid the situation when the PSU’s protection is triggered by overcurrent on an individual “virtual” line rather than by total overload.
A minor drawback is that the connectors’ keys allow plugging a HDD power cable instead of a graphics card cable. Be careful and match the color of the connectors: black with black and red with red.
Included with the PSU are:
This selection of connectors is overall good but I guess a 750W power supply should have longer cables, especially a longer CPU cable because the 52cm one may not be long enough in most system cases with a bottom PSU compartment. The manufacturer should also have included at least one more SATA cable into the box (perhaps instead of a PATA cable even).
The PSU can yield up to 650 watts across its +12V rail which is split up into four virtual lines.
Notwithstanding its dedicated voltage regulation, the APS-750C performs worse in this test than the CFT-600-14CS. The three main voltages are within a 3% deflection under typical loads, though, and none of them deflects more than 4% under any allowable load, so this PSU honestly gives you each watt written in its specs.
There are short spikes of voltage on the +5V rail a little above the allowable limit, but you shouldn’t worry about them much. Otherwise, the PSU complies with the ATX12V requirements regarding the output voltage ripple.
The PSU has a 140mm fan made by Globe Fan. About one quarter of its impeller is covered with a transparent plate that drives the air into the back part of the case for better ventilation.
The fan starts out at a speed of 900 RPM but the PSU is not really quiet. The fan is as fast as 1000 RPM at a load of 300 watts. Thus, the APS-750C is average in terms of noisiness. It will satisfy most users, especially at low loads, but people who want complete silence may be disappointed with it.
Together with my APC SmartUPS SC 620 this power supply worked at loads up to 360 watts when powered by the mains. But when the pair switched to the batteries, the UPS would shut down in a couple of seconds even at a load of 300 watts.
The efficiency is about 86% at the maximum, but quickly falls below 80% at low loads.
The standby source copes with its job well: its output voltage is no lower than 5.0 volts under maximum load.
The Chieftec A135 Series APS-750C is just a good power supply. It is stable and quiet (but not exactly silent) but has poor compatibility with UPSes (at least, UPSes that have a non-sinusoid output voltage). You should not confuse it with the A135 series models that have the letter S at the end of the model name because it is based on a completely different platform and has different characteristics (even though the difference is not large in terms of practical applications). Comparing the APS-750C with the CFT-750-14C, I cannot easily name the better product. The former is somewhat quieter but the latter works well with UPSes. Both models have rather short cables: you may find this to be a real problem if you are assembling your computer in a large system case.