GlacialPower is not one of the biggest players in the power supply market, and so we have one big question: do they manufacture decent products or are they just another manufacturer you should avoid? Today we are going to make a complete test on their latest 650 W model, GP-AL650AA, to see if it can really deliver 650 W, the quality of its outputs and its efficiency. Check it out.
GP-AL650AA has a very simple looks, being only 5 1/2” (140 mm) deep, as you can see on Figures 1 and 2. It features a 120 mm fan on its bottom, active PFC and no modular cabling system. No special attention was given to the aesthetic side, as only the main motherboard cable has a nylon sleeving coming from inside the unit.
Figure 1: GlacialPower GP-AL650AA power supply.
Figure 2: GlacialPower GP-AL650AA power supply.
This unit has an interesting feature: its fan keeps spinning after you turn the unit off, to cool it down.
The main motherboard cable uses a 20/24-pin connector and this unit comes with two ATX12V connectors that together form an EPS12V connector.
This power supply comes with six peripheral cables: Two cables with a 6/8-pin video card auxiliary power connector each, two cables with six SATA power plugs each, one cable with three standard peripheral power plugs and one cable with three standard peripheral power plugs and one floppy disk drive power plug.
We think the number of connectors is satisfactory for the average user.
All wires are 18 AWG, which is the correct gauge to be used nowadays.
This power supply is manufactured by CWT with a design created by GlacialPower.
Now let’s take an in-depth look inside this power supply.
[nextpage title=”A Look Inside The GP-AL650AA”]
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 and to compare this power supply to others.
[nextpage title=”Transient Filtering Stage”]
As we have mentioned in other articles and reviews, 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, usually removing the MOV and the first coil.
The transient filtering stage from this power supply comes with two extra X capacitors, plus one extra X capacitor and two extra Y capacitors after the rectification bridge. This unit, however, doesn’t have a MOV, which is in charge of removing spikes coming from the power grid.
Figure 6: Transient filtering stage.
Now let’s have a more detailed look inside GlacialPower GP-AL650AA.
[nextpage title=”Primary Analysis”]
On this page we will take an in-depth look at the primary stage of GP-AL650AA. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.
This power supply uses one GBU1506 rectifying bridge in its primary, capable of delivering up to 15 A at 100° C. This component is clearly overspec’ed: at 115 V this unit would be able to pull up to 1,725 W from the power grid; assuming 80% efficiency, the bridge would allow this unit to deliver up to 1,380 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.
The active PFC circuit uses two STW25NM50N power MOSFET transistors. Each one is capable of handling up to 88 A @ 25° C in pulse mode (which is the case) or up to 22 A @ 25° C or 14 A @ 100° C (note the difference temperature makes).
The big electrolytic capacitor used on the primary is from OST and rated at 85° C.
Figure 7: Active PFC transistors, active PFC diode and rectifying bridge.
The active PFC circuit is controlled by the omnipresent CM6800 PFC/PWM combo controller.
Figure 8: Active PFC/PWM controller.
On the switching section this power supply uses another two STW25NM50N transistors, on the traditional two-transistor forward configuration. The specs for these transistors are published above.
Figure 9: Switching transistors (the small transistor between them is for the +5VSB output).
[nextpage title=”Secondary Analysis”]
GlacialPower GP-AL650AA uses six Schottky rectifiers on its secondary.
The maximum theoretical current each line can deliver is giv
en by the formula I / (1 – D), where D is the duty cycle used and I is the maximum current supported by the rectifying diode. Just as an exercise, we can assume a typical duty cycle of 30%. Of course the maximum current (and thus power) this line can really deliver will depend on other components, especially the coil.
+12 V rectification is done by two SBR40U60CT Schottky rectifiers, each one supporting up to 40 A (20 A per internal diode at 150° C), so we have a maximum theoretical current of 57 A (20 A x 2 / 0.70), which corresponds to 686 W.
The +5 V output is produced by two STPS30L30CT Schottky rectifiers, each one capable of handling up to 30 A (15 A per internal diode) at 140° C. This translates into a maximum theoretical current of 43 A or 214 W.
The other two Schottky rectifiers present are used to rectify the +3.3 V output, however they are not identical. For the direct rectification one STPS20L45CT is used (10 A per internal diode at 135° C), while for the “freewheel” diode one STPS30L30CT is used. For our calculations we have to consider only the diode used on the direct rectification, so the maximum theoretical current the +3.3 V output can deliver is 14 A or 47 W.
Figure 10: +3.3V, +5V and +12 V rectifiers.
The outputs are monitored by a WT7525 integrated circuit (not shown in Figure 11), which supports the following protections: over current (OCP), under voltage (UVP) and over voltage (OVP). Any other protection that this unit may have is implemented outside this integrated circuit.
Figure 11: Monitoring circuit.
The electrolytic capacitors from the secondary are also from OST, labeled at 105° C as usual.[nextpage title=”Power Distribution”]
In Figure 12, you can see the power supply label containing all the power specs.
Figure 12: Power supply label.
This power supply features two +12 V virtual rails distributed like this:
- +12V1 (solid yellow wire): All cables but the ATX12V/EPS12V cable.
- +12V2 (yellow with black stripe wire): ATX12V/EPS12V cable.
Now let’s see if this power supply can really deliver 650 W.
[nextpage title=”Load Tests”]
We conducted several tests with this power supply, as described in the article Hardware Secrets Power Supply Test Methodology.
First we tested this power supply with five different load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching how the reviewed unit behaved under each load. In the table below we list the load patterns we used and the results for each load.
For the 100% load test we used two patterns. The first one, test number five, we respected the limits printed on the power supply label (504 W maximum for the +12 V outputs). To achieve this pattern, however, we had to configure the +12 V outputs with a current lower than we wanted, and increase current on +5 V and +3.3 V outputs to a value higher than we wanted. After testing the power supply with this pattern, we configured our load tester with the pattern described below as test six, increasing current on +12 V outputs and lowering current on +5 V and +3.3 V outputs, which is the standard we use on our tests.
+12V1 and +12V2 are the two inputs from our load tester and during our test they were connected on the power supply +12V1 and +12V2 rails, respectively.
|Input||Test 1||Test 2||Test 3||Test 4||Test 5||Test 6|
|+12V1||5 A (60 W)||10 A (120 W)||14 A (168 W)||19 A (228 W)||21 A (252 W)||26.5 A (318 W)|
|+12V2||4.5 A (54 W)||10 A (120 W)||14 A (168 W)||19 A (228 W)||21 A (252 W)||22 A (264 W)|
|+5V||1 A (5 W)||2 A (10 W)||4 A (20 W)||5 A (25 W)||16 A (80 W)||6 A (30 W)|
|+3.3 V||1 A (3.3 W)||2 A (6.6 W)||4 A (13.2 W)||5 A (16.5 W)||15 A (49.5 W)||6 A (19.8 W)|
|+5VSB||1 A (5 W)||1 A (5 W)||1.5 A (7.5 W)||2 A (10 W)||2.5 A (12.5 W)||2.5 A (12.5 W)|
|-12 V||0.5 A (6 W)||0.5 A (6 W)||0.5 A (6 W)||0.5 A (6 W)||0.5 A (6 W)||0.5 A (6 W)|
|Total||138.1 W||265.0 W||378.0 W||500.0 W||645.0 W||630.0 W|
|% Max Load||21.2%||40.8%||58.2%||76.9%||99.2%||96.9%|
|Room Temp.||46.0° C||45.8° C||45.9° C||45.2° C||48.4° C||47.1° C|
|PSU Temp.||46.7° C||46.3° C||46.6° C||45.2° C||48.5° C||48.3° C|
|Ripple and Noise||Pass||Pass||Pass||Pass||Pass||Pass|
|AC Power||155 W||293 W||426 W||575 W||778 W||755|
GlacialPower GP-AL650AA achieved an outstanding efficiency when we pulled up to 80% of its labeled power (520 W): between 87% and 90.4%. In fact this is one of the few power supplies that during our tests achieved over 90% efficiency. The problem, however, is that when delivering 650 W efficiency drops a lot, to 83%, but still above 80%.
Noise and ripple were at very good levels. During test number five we saw 63.8 mV at +12V1, 66.4 mV at +12V2, 25.2 mV at +5 V and 39 mV at +3.3 V. The maximum allowed values are 120 mV for the +12 V outputs and 50 mV for the +5 V and +3.3 V outputs. Ideally, however, the power supply should achieve only half of this, so the only point where GlacialPower could improve is the noise level on +3.3 V output, even though it is below the maximum allowed. All values are peak-to-peak.
Figure 13: Noise level at +12V1 during test five (63.8 mV).
Figure 14: Noise level at +12V2 during test five (66.4 mV).
Figure 15: Noise level at +5 V during test five (25.2 mV).
Figure 16: Noise level at +3.3 V during test five (39 mV).
Now let’s see if we can pull even more power from GP-AL650AA.
[nextpage title=”Overload Tests”]
Before overloading power supplies we always test first if the over current protection (OCP) circuit is active and at what level it is configured. We configured current on +12V1 to 1 A and increased current on +12V2 to 33 A and the power supply didn’t shut down. This means that either the OCP circuit is disabled or is configured at a value above 33 A. We don’t like this, especially when the label says the +12V1 rail has a 25 A limit and +12V2 rail has a 20 A limit.
This unit, however, has over power protection and we saw it in action. If we tried to pull too much power from this unit it would shut down, what is great. Below you can see the maximum we could pull from this power supply without it shutting down. Noise level at both +12 V rails was around 72 mV. See how efficiency was still above 82%.
|+12V1||28 A (336 W)|
|+12V2||28 A (336 W)|
|+5V||8 A (40 W)|
|+3.3 V||8 A (264 W)|
|+5VSB||2.5 (12.5 W)|
|-12 V||0.5 A (6 W)|
|% Max Load||112.8%|
|Room Temp.||47.1° C|
|PSU Temp.||48.3° C|
|AC Power||888 W|
[nextpage title=”Main Specifications”]
GlacialPower GP-AL650AA power supply specs include:
- Nominal labeled power: 650 W
- Measured maximum power: 733 W at 47.1° C.
- Labeled efficiency: 86% at 50% load at 230 V.
- Measured efficiency: Between 82.9% and 90.4% at 115 V.
- Active PFC: Yes.
- Modular Cabling System: No.
- Motherboard Power Connectors: One 20/24-pin connector and two ATX12V connectors that together form one EPS12V connector.
- Video Card Power Connectors: Two 6/8-pin connectors.
- Peripheral Power Connectors: Six in two cables.
- Floppy Disk Drive Power Connectors: One.
- SATA Power Connectors: Six in two cables.
- Protections: over current (OCP, tested and not working), over voltage (OVP, not tested), over power (OPP, tested and working), over temperature (OTP, not tested) and short-circuit (SCP, tested and working).
- Warranty: Five years.
- More Information: https://www.glacialpower.com
- Average Price in the US: This product isn’t sold in the USA retail market.
We were absolutely impressed by GlacialPower GP-AL650AA, especially since it comes from a not so well-known company. It can deliver its labeled power at 48° C and was one of the few units we tested to date to surpass the 90% efficiency mark! Ripple and noise levels were also at very good numbers. Even though it has a very Spartan looks, GlacialPower GP-AL650AA has nothing to do with other units around with simple looks that simply explode if you try to pull its full labeled power or that present mediocre efficiency.
Now GlacialPower needs to invest in marketing to make sure people will know they have good products. And by “marketing” we don’t mean “advertising,” but simply the ability to bring this product to a wider market.
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