|Introduction & OCZ 700W GameXStream Specs & Features|
As computer enthusiasts, we all love to see PC components get more and more powerful. Unfortunately, with this increasing power often comes an increase in power demands. This is especially true of video cards. In fact, it can be reasonably argued that if it weren't for the high-end video card market, power supplies probably wouldn't be anywhere near the 600W or more that we see in typical enthusiast-level PSUs these days.
When you begin to crave high-end dual or quad GPU configurations, you must realize that a high quality and high capacity power supply is probably in your future. Fortunately, both NVIDIA and ATI make your search for an acceptable PSU a little easier as both companies have certification programs to verify if a PSU is suitable for multiple video cards.
Today, we have two beefy PSUs on the test bench, both of which have been deemed NVIDIA SLI Ready and ATI CrossFire Certified. The two PSUs are the 700W OCZ 700W GameXStream and the 620W Enermax Liberty. The Liberty is a modular PSU while the GameXStream has a standard output cable configuration. Rather than just simply run tests on each PSU, we installed and left each PSU in one of our test systems for around 20 days. The test system was used mostly for benchmarking and gaming. First up to the plate was the 700W GameXStream from OCZ.
OCZ packs the GameXStream PSU in a long box that features a design that inspires thoughts of electricity (go figure) and power. We'd like to see a little more protection around the unit itself since the delivery guys and gals don't always like to play nice with packages. The PSU comes with the regular accouterments, including a small booklet, four screws and a power cord.
The 700W GameXStream is a high efficiency PSU that features active PFC and a quiet 120mm fan. According to OCZ, this PSU will perform maintain least 80% efficiency. The back of the unit is a honeycomb grill that should allow hot air to exit your system freely and easily.
As we mentioned above, the GameXStream is not a modular PSU. You can see all of this PSU's cables in the pictures above. In addition to the power connectors, you get two PCI Express connectors, six 4-pin (Molex-style) peripheral connectors, two floppy connectors and six SATA connectors. The Molex connectors are the nice, easy disconnect type, which is definitely a nice choice.
|Test System & GameXStream Test Results|
* Test Methodology: For testing the 700W GameXStream PSU, we used a relatively high-end gaming PC configuration that includes an Athlon 64 X2 4600+ processor on a DFI LANParty NF4 SLI-DR motherboard with a pair of GeForce 7900 GTX cards in SLI. We also used 2GB of low latency Corsair DDR and two SATA hard drives. In an effort to stress the PSU, we looped 3DMark06 while running SiSoftware's SANDRA 2005 burn-in tests.
We let the test system run idle for 30 minutes and then recorded the voltages. Then we stressed the PSU and recorded the voltage levels about 30 minutes into the stress testing. You can see the resulting outputs below.
As you can see, the GameXStream performed very well. The voltages barely even fluctuated when we stressed out the system. This is exactly the kind of performance we want out of a power supply. Steady, consistent voltage leads to increased stability of the system. Also recall that this PSU was used in a test machine for over two weeks, during which time we experienced no stability problems.
In addition to providing steady voltage, the GameXStream stayed pretty cool thanks to its 120mm fan. It also looks cool thanks to its blue LEDs. Now that we've taken the GameXStream through the paces, it's time to spend some time with the Enermax Liberty.
|Enermax 620W Liberty Specs & Features|
While OCZ is known more for its memory products and is a relative newcomer to the PSU scene, Enermax has been creating power supplies for quite some time. Enermax was established in 1990 and released its first AT switching power supply in 1991. OCZ delivered with its GameXStream; now, let's see if veteran Enermax can do the same with the 620W Liberty.
Unlike the OCZ GameXStream, the Enermax Liberty is a modular PSU. For those of you who are unaware, a modular PSU is one that allows you to connect only the cables you need for your system configuration. This often reduces the number of cables that you have to deal with inside your case and hopefully reduces clutter, which can lead to improved airflow.
The popularity of modular PSUs is quite evident as almost every major PSU manufacturer has introduced at least one modular model. The convenience of the modular design has to take a back seat to the stability and overall quality of the unit, though, so let's take a look at the Liberty's features and then get to the test results.
The Liberty packaging is simple and straightforward. The box emphasizes the unit's features and specifications. Inside the box, Enermax includes four screws, an Enermax sticker, an Enermax lanyard, a User's Manual, the modular cables, a pouch for storing the cables and of course the PSU itself.
As you can see from the first picture above, not all of the cables can be disconnected. The power connectors and the fan monitoring cable are not modular. Like the GameXStream, the Liberty features a 120mm fan to keep its internals cool. The rest of the cables, which you can see in the second and third pictures, are of course modular. Enermax even went the extra mile and included a pouch for the cables. As expected, the cables include two PCI Express connectors and two floppy drive connectors. What wasn't expected was finding ten 4-pin peripheral (Molex) and ten SATA connectors. This is what Enermax calls its Eternity cabling system. For each pair of Molex connectors, you get a pair of SATA connectors. The goal of this configuration is to provide the user with maximum flexibility. The downside is that Enermax recommends that you only use three of the four connectors on each cable. Another nice little touch is the inclusion of the EASY PLUG design on the Molex connectors, which makes them easier to detach from peripheral devices.
Here you can see the Liberty's modular connectors. The two dark red connectors are for PCI Express. Once we turn the unit around, you can see the AC power connector and the honeycomb grill that allows hot air to flow out of your system.
|Liberty Test Results|
* Test Methodology: To test the 620W Liberty PSU, we followed the same procedure as with the OCZ GameXStream. We used a relatively high-end gaming PC configuration that includes an Athlon 64 X2 4600+ processor on a DFI LANParty NF4 SLI-DR motherboard with a pair of GeForce 7900 GTX cards in SLI. We also used 2GB of low latency Corsair DDR and two SATA hard drives. In an effort to stress the PSU, we looped 3DMark06 while running SiSoftware's SANDRA 2005 burn-in tests.
We let the test system run idle for 30 minutes and then recorded the voltages. Then we stressed the PSU and recorded the voltages about 30 minutes into the stress testing. You can see the resulting voltages below.
As with the GameXStream PSU, we used the Liberty in the test system for over two weeks. During that time, we didn't see any stability problems. We were quite pleased by the performance of the Liberty. The PSU posted very stable voltages. Additionally, the 120mm fan kept the unit relatively cool throughout testing.
|Performance Summary & Conclusions|
Performance Summary: Both the 700W OCZ GameXStream and 620W Enermax Liberty performed quite well in our demanding test system. While the GameXStream's voltages fluctuated a little less than the Liberty's, both PSUs were very stable while the system was idle and when the system was under load.
OCZ 700W GameXStream Conclusion: OCZ continues to impress as it matures in the PSU market. The 700W GameXStream is a top notch PSU, offering rock solid stability and plenty of power. If you don't need 700W, OCZ also makes a 600W version.
OCZ includes plenty of connectors on the relatively long cables with their GameXStream series PSUs. We had no problems with cabling in our standard ATX test system. The only issue was finding a place to hide the extra cables and connectors we didn't need. The GameXStream proved to be a relatively quite PSU and actually looked quite cool when it was on, thanks to its blue LEDs.
At around $160, this PSU may seem expensive, but you really do get what you pay for. Good quality PSUs cost more than mediocre ones, and we feel that this one is worth every penny. We recommend you add it to your shopping list if you are in search of a high-end power supply. We are awarding the OCZ 700W GameXStream a 9 on the Heat Meter.
Enermax 620W Liberty Conclusion: A lot of people like modular power supplies because they can make keeping a tidy case a bit easier. In our test system, the Liberty proved to be a good offering for those seeking this type of PSU. Our test unit provided stable voltages and clean power throughout the testing period.
The cables were of adequate length in our standard ATX case, and there were definitely plenty of connector options. We find Enermax's Eternity SATA/Molex configuration to be rather interesting. While it does provide greater flexibility for the user, it might be forgotten that you aren't supposed to use all four connectors on a single cable (recall that we earlier pointed out that Enermax recommends only using three of the four available SATA/Molex connectors on a cable). Though frankly this is rare configuration for most folks to be sure. Finally, thanks to the 120mm fan, the unit did remain cool and quiet.
The 620W Enermax Liberty (ELT620AWT) can be purchased for about $150. Again, this may seem expensive to some of you, but it is a good quality PSU. We're happy to see that Enermax has lived up to its long-standing reputation for quality with this power supply. We are awarding 620W Enermax Liberty an 8.5 on the Heat Meter.