Legit Reviews

Posted: **Wed Jul 26, 2006 2:36 pm**

The Ultra X-Connect X2 550W Power Supply Update

Last month in the 8-way SLI and Crossfire Power Supply (PSU) Roundup we found that not every power supply makes the cut on the high end gaming systems that we used for testing. One of the power supplies that ended up in our yellow caution zone was the Ultra X-Connect X2 550W power supply.Ultra was logically unhappy with where their product finished in our review. After the article was published Ultra Products started to get feedback from our readers and their current customers. They then took the time to duplicate our test systems in their labs, minus the AGEIA PhysX card, and believe they found the answer to why it didn't do so hot. It was determined that the 12V might have dropped as much as it did because it had very little load on the 3.3V/5V rails.

Ultra goes on to inform Legit Reviews that we need at least a 45A load on the 3.3V/5V rail if you're going to put as much as a 37A load on the 12V rail. So in other words, Ultra said their power supply might actually perform better with four hard drives hooked up to it than it would with just one. Since we tested with only one hard drive this could be the case and since Ultra was concerned with our findings we went back to the test bench and installed three more Western Digital 250GB hard drives.

Article Title: The Ultra X-Connect X2 550W Power Supply Update
Article URL: http://legitreviews.com/article/368/1/

Posted: **Wed Jul 26, 2006 3:34 pm**

Did they add more hard drives in their tests and see better numbers? I'm just wondering why they would recommend adding more hard drives if it still didn't help performance...

Glad to hear they are easy to work with and understanding!

Posted: **Wed Jul 26, 2006 4:49 pm**

Did they send you their numbers and test set up so that you can compare? I would be interested in seeing exaclty their setup and how their numbers differ.

Posted: **Wed Jul 26, 2006 4:53 pm**

Illuminati wrote:Did they add more hard drives in their tests and see better numbers? I'm just wondering why they would recommend adding more hard drives if it still didn't help performance...

Glad to hear they are easy to work with and understanding!

Ultra said that after they added four hard drives the 12V rail improved due to better load balancing, but my testing did not show that.

Posted: **Wed Jul 26, 2006 6:11 pm**

Are you claiming AC power draw as the 635W performance? Don't forget the PSU's inefficiencies if you are

Dan

Posted: **Wed Jul 26, 2006 6:17 pm**

Wow... a company that is as friendly and cooperative as Ultra deserves a round of applause from the community. I respect them for sure now and I do hope they bring in some more powerful hardware

Posted: **Wed Jul 26, 2006 8:54 pm**

well I respect them too, but there logic makes no sense. this screams of poor design. hugs OCZ Powerstream that I won here

Posted: **Thu Jul 27, 2006 12:38 pm**

EDIT: Whoa! I'm not only registered here... I'm also logged in! The ultimate lurker!!!

Back on topic....

The logic really isn't flawed at all.

Any power supply has a minimum load requirement for the 3.3V/5V rail. What that minimum actually is can vary from power supply to power supply, though. Unfortunately, there's no magic number (like 10% or something.)

Take a power supply and load up just the 12V rail, with a pump, TEC or lights, etc. while nothing is on the 5V rail. You'll find the 12V rail drop much more exponentially than if it was hooked up to a PC with a fairly good balance of 5V and 12V loads. Ask anyone who runs two PSU's in their rig, and uses the second PSU for a pump, TEC, etc. They're either using a ballast resistor on one of the PSU's red wires or are complaining about a 12V rail running around the neighborhood of 10V!

In a rig like Nate's there's a serious 12V load. And quite possibly a very minimal 3.3V and 5V load (seeing how initially there was only one hard drive and one optical drive.) If you were to add a second drive, the logic board of the drive, being that it uses 5V, and add more RAM, since it uses the 3.3V rail, you would bring that balance up reducing the crossload (that's the word for an uneven load on a power supply.)

My guess is since Nate also upgraded the CPU (which uses the 12V rail) and had the optical drive spinning during the load test (optical's motor uses 12V) then quite possibly the 12V rail was just pushed beyond what it's capable of. Naturally, this would cause the 12V rail to drop no matter what was using the 3.3V or 5V rails. Of all of the power supplies reviewed in that round up, I believe the X2 had the lowest combined 12V rail capability.

Posted: **Wed Aug 02, 2006 3:21 pm**

I saw this review the other day and wanted to say how much I apreciated that you did a honest review. I am kind of tired of seeing reviews that just seem to repeat the companies product details.
I have several of the Ultra PS and they work fine if you dont push them hard.

Posted: **Wed Aug 02, 2006 3:28 pm**

yeah with one video card and a normal system they do great.

Posted: **Wed Aug 02, 2006 4:25 pm**

I think that would be a good sticky. Being realistic with ur power needs. And value( I got my Ultra PSs for $9.99) I wouldnt pay $149 (MSRP)

I use a Silverstone 400 (great value at $45)with my SLI (7600GS/32 watts each)

But if ur going X1800XT/ X1900 in crossfire ur gonna need a lot more.