The Competition

The last couple of months, many different power supplies have been tested here at Madshrimps, some of which are still available for a comparison to the ProXstream we're reviewing today. For this test we chose the previous top of the line from the OCZ PSU range, the GameXstream 700W, and the Silverstone Zeus 750W PSU, which made quite a showing in our PSU roundup last summer.


left and right : Silverstone Zeus and OCZ GameXstream

The GameXstream is a PSU that has been built by Fortron/FSP, whereas the Silverstone is an Etasis unit. The ProXstream comes from 3YPower as we already mentioned, so this little roundup should be an interesting comparison of three major PSU manufacturers.


Comparison of the three test candidates

Here's the table with the specifications of all three contestants:

Power Comparison of the Contestants
	Silverstone Zeus ST7S 750W		OCZ GameXstream 700W		OCZ ProXstream 1kW
Load range	Nominal	Peak	Nominal	Peak	Nominal	Peak
3.3V	24A		36A		28A
5V	30A		30A		30A
12V1	18A	22A	18A		20A	26A
12V2	18A	22A	18A		20A	26A
12V3	18A	22A	18A		20A	26A
12V4	18A	22A	18A		20A	26A
+5VSB	3.0A		3.0A		3.5A	4A
-12V	0.5A		0.5A		0.5A
-5V
3.3V/5V combined		180W		155W		150W
12V combined		720W/60A				840W/70A
3.3/5/12V combined				680W
Total load	750W		700W		1024W

As you can see, the ProXstream is clearly more powerful on the 12V rails, with 20A on every rail compared to 18A for the other two contestants. On the 3.3V and 5V rails, the ProXstream is even a little less powerful than the other two, but in total power the ProXstream clearly outguns them with its higher rating of 1000W vs 750W and 700W respectively.

Let's have a look at the differences in connectivity:

Connectivity comparison
	Silverstone Zeus	OCZ GameXstream	OCZ ProXstream
Type
Motherboard	24pin	20+4pin	20+4pin
EPS	8pin	4+4pin	8pin
PCIe	2 (+2*)	2	4
SATA	2x 2	2x 3	2x 3
Peripheral	3x 2	2x 3	2x 3
Floppy	2	2	2
Extra	6 pin AUX		4 pin AUX

The Silverstone also has the possibility of connecting up to four graphics cards (or two cards with two connectors each) out of the box, whereas the GameXstream is only meant to drive two. The Silverstone needs to sacrifice the Auxiliary connector and two molexes to do so however. The ProXstream of course has the four PCIe connectors which means quad SLI (or dual 8800GTX) without any hassle.


Test Setup

To perform the tests on the power supplies, we put together a powerful test setup built around an Intel Core 2 Duo chip :

Conroe Test Setup
CPU	Intel Xeon 3220 Core 2 Quad @ 3.0Ghz Cooled by Tuniq Tower 120
Mainboard	Asus P5B-deluxe - Wifi/AP (modded)
Memory	2x 1024Mb Corsair Dominator PC8888
Other	nVidia 8800GTX Nec 3450 DVD writer Western Digital Raptor WD800 Seagate Barracuda 80Gb Lian-li fan controller + 3x 120mm fans Silverstone Zeus 750W OCZ GameXstream 700W OCZ ProXstream 1000W

The entire setup was built into a Silverstone Temjin TJ09 case to create a situation as realistic and stressful as possible. We overclocked the CPU from the standard 2400Mhz to 3000Mhz. The 8800GTX was pushed up from the standard core/mem 576/900 to 630/2060. This should increase the power draw a little over the standard configurations.

The tools for our testing were the following: dBA meter, multimeter and a standard Power (Watt) meter.

Let's see how they did ->