Sigma Shark 635 Watt ATX Power Supply Review

ajmatson - 2007-08-28 10:19:55 in Power Supplies
Category: Power Supplies
Reviewed by: ajmatson   
Reviewed on: November 4, 2007
Sigma Products
Sigma Products
Price: $99.99


I have seen it happen time and time again. Someone will bring me a list of what they want to buy to build a sweet gaming rig, or that server needed to host their critical files and they overlook one of the most important items. Sure, the Quad Core CPU will blaze through tasks like candy and that $500 video card will slice into max settings on any game out. Until I get to the end and see Generic 400W Power Supply for $35. A good PSU is the heart of any computer. Without it, the computer will not function. With all of the power supplies out there, how do you choose the right one though? It's not hard - you just have to find the one with the right balance of power and price. That's easy with the Sigma Shark 635w PSU.


Closer Look:

The Sigma Shark 635 Watt power supply comes boxed with a design that gives a taste to what the inside has to offer. If you are like me and enjoy the subtle lights neons glowing in your case, the front of the box will catch your eye with the blue illuminated fan showing. The back will give you a glimpse of the beast inside, along with highlights of the power supply.



The sides reiterate the features, as well as giving you information on the voltages for each of the two rails.



When you open up the flap on the box you, get to see what this power supply is made of. It is packaged tight to protect it and has all of the cables wound neatly to keep them from crimping while shipped. Getting the Sigma Shark 635 Watt PSU out of the box, you will notice that this one has all of the cabling wrapped with a black nylon mesh. This is a nice move by Sigma, as looks and cable management are a top priority for a true computer enthusiast. Included in the box is the Sigma Shark 635 Watt PSU, with mounting screws and the power cable. No instructions are included however, so you must know what you are doing to install it or just read here and I will show you coming up.


Now that we have the Shark unpacked, let's take an even closer look and see what sets this predator apart from the rest of the pack. First, with the outside you can see the voltage chart on the top of the unit. This gives the ranges for the voltage levels you need. When you flip it over you get a really good look at the two 80mm blue LED fans that pull in air from the case and spit it out to cool the internals of the power supply. 





Now for the front and back of the unit. You will notice the holes in the housing. This is the Hexflo honeycomb technology that Sigma uses to promote maximum airflow keeping the inside of the PSU from over-heating. You can also see the weird fin-like metal by the fans. This turns the aluminum housing into one big heatsink, pulling the hot air from the inside of the PSU and dissipating it into the flow of air from the case. This PSU stays cool to the touch, even under full load. On the back side, you have a standard wall plug outlet the power switch and the 110 to 240 switch.



Finally, you can see the meshing that covers the cables. You can see the effort that went into manufacturing this, because all of the cables are meshed perfectly and the shrink wrap is placed in the exact spots to keep the mesh from coming undone. This shows the time and work that went into making this unit and the dedication Sigma has to making its customers happy.


Now that the outside is out of the way, let's open her up and take a look inside. I do want to warn you that opening your power supply will void your warranty, as the company places tell-tale signs that will alert them if you open it. Since this is a critical working component, you may need the warranty one day. That aside, this is a power converter and is HIGHLY DANGEROUS! One wrong move, or touching the internals, even when it is not plugged in, can give off a fatal jolt of electricity. The capacitors in the unit can hold a charge for hours or even days, so I urge you to not open a power supply. That is what we, the professionals, are here for - so you do not have to take the risk.

With that aside, here is the core of this monster of a power supply. Here you can get a view of the two 12 volt rails used in this PSU, to balance power for your system and the large capacitors to keep the power continuous. You can also get a better look at the time and craftsmanship that went into making the power supply.



Now let's get a closer look at the connections and the inside of the power supply.

Closer Look:

There are plenty of connections that are included with this power supply. This unit does support SLI, which is a big plus for those that have two graphics cards and since it is an enthusiast's product, it needs to be on the cutting edge. First up are the main plugs of the unit. It has a 20+4 main connector for any new or old motherboard on the market. It also has two 4-pin CPU connectors that can be combined to make an 8 pin plug for newer motherboards.





There are connections galore too. Here you get a look at the two PCI Express plugs, four SATA plugs, eight 4-pin molex plugs, and two floppy plugs.




So let's put this baby back together and get on to installing it into our test rig.


To install a power supply is quite simple and only takes a couple of steps. First thing you will want to do if you haven't already, is to remove the old power supply. To do this, first unplug all cabling from the motherboard and any components. Then remove the four screws in the back of the computer chassis going into the computer supply. Tilt the supply downward and out of the case. Since this is so close to the CPU fan and parts of the motherboard I suggest you work slowly and cautiously, so that you do not cause any damage to the parts of the computer. If your case has a removable motherboard tray I suggest taking it out prior to changing the PSU.




Now that the old one is out, let's install the new one. Carefully slide the Shark into the PSU bay, watching that you don't damage any of the motherboard components or the CPU fan. Once into position, take the four screws included in the packaging and screw them in to secure the PSU. If you're into cable management like myself, now would be a good time to plan where you want your wires to go. Then plug in all of the cables needed and tuck away the ones not being used. This creates better airflow in the case.



Now that it is all set up and plugged in, insert the main power plug into the back of the PSU and the wall, turn on the switch and start the computer. Sit back and enjoy the work you have just accomplished. Here you can see the nice blue glow that the power supply gives off in my system. I love how it is just the right amount of light, not too dim and not bright. Perfect to accentuate the internals of the system.



Note: This is just a guide for users that have knowledge of a computers working parts and takes no responsibility if damage occurs while changing your PSU. If you are not experienced in computer hardware, I recommend that you take your computer to a professional to avoid any problems.



Model Number
Total Output:
635 Watts
Housing Body:
Black Aluminum
ATX 4-Pin Molex:
SATA Power Plugs:
PCI Express Plugs:
Main ATX Power Plug:
20 + 4
CPU Power Plug:
4 + 4


Now that the power supply has been installed, let's take a look at how it performs. I am going to monitor the voltage of each rail for the 3.3v, 5v, and 12v ranges and compare this 635w power supply to an Antec EarthWatts 500w PSU and the Cooler Master Real Power Pro 750w PSU. I will be testing the Idle and Loads variances using a Digital Multimeter. To get the load on the system I will be running Stressprime 2004 Orthos Edition for the CPU and Memory, HDTune for the hard drive and 3DMark06 for the video card.

Testing Setup:
Power Supplies Tested:
Testing Equipment:


First up are the 3.3 voltages. Remember you want to be as close to the 3.3v as possible.



Now we have the 5.0 volts



And lastly  for the 12 volt rails.



As you can see, the Sigma is right on-par with two well-known power supply manufacturers, showing the quality that went into making this unit. Even under a full stress load, the Shark kept the voltages needed, never dipping below the marks and thus giving you the power you need to run your system.


I have to say I am one of those guys who likes the flashy light stuff inside my case, so this power supply got my attention rather quickly. It wasn't until I was actually using it that I fell in love with it. It does the job and it does it well. This just goes to show that you can get a great power supply for not a lot of cash, so stop looking at those sub par $30 ones and get yourself a decent power supply. This unit cost the same or less than the other two it was compared to and kept either on-par or better then them. Even under load, this unit kept its cool and gave me the power I needed to stress the system without any hiccups. I like how Sigma brought together flashiness with performance, which you don't see much of these days. It is usually either the looks or the performance, but not both. They come in black and silver and in 635W and 585W versions for any need.

I would highly recommend this power supply to anyone that is looking for an inexpensive unit that is on-par with more costly ones. It will give you enough power to run virtually any setup from the workstation to the high-end gaming rig. This PSU took everything I threw at it and kept its cool the whole time, never leaving me needing more power. The Sigma Shark is a definite keeper in my system.