400-450W PSU Roundup
by Christoph Katzer on November 6, 2007 4:00 AM EST- Posted in
- Cases/Cooling/PSUs
Corsair PFC, Temperature, Fan Speed, and Acoustics
Again, we find that the exhaust temperature is much lower than the heatsink temperatures. This indicates the heatsinks are not properly dissipating heat into the streaming air. Instead, the heat stays inside the power supply and builds up over time. While the positioning of the fan and perhaps the airflow might be to blame, the more likely problem is that the heatsinks simply aren't large enough and lack sufficient surface area. In our stress test heat chamber, we see the temperatures that are twice as high as the exhaust temperature, with the secondary heatsink reaching 85°C at the worst-case 110% load. Running a PSU under such conditions for an extended period of time would almost certainly result in a dead power supply, but it did manage to survive our short-term stress test.
Up to medium load, the power supply is extremely quiet registering less than 20dB(A). Higher loads result in increased fan speed and noise levels, and in our stress chamber we reach a maximum noise level of 28dB(A) at 80% of load (350W). However, 28dB(A) is still very quiet so in terms of noise levels users should be very pleased with Corsair. The problem is, low noise levels and low fan RPMs contribute to the relatively high heat sink temperatures. We are not sure if Corsair really tested this unit under stressful conditions - maximum load and a high ambient temperature - and we would caution users against using any of these power supplies in such an environment. Under more sedate operating conditions, however, the Corsair 450VX performs extremely well.
Again, we find that the exhaust temperature is much lower than the heatsink temperatures. This indicates the heatsinks are not properly dissipating heat into the streaming air. Instead, the heat stays inside the power supply and builds up over time. While the positioning of the fan and perhaps the airflow might be to blame, the more likely problem is that the heatsinks simply aren't large enough and lack sufficient surface area. In our stress test heat chamber, we see the temperatures that are twice as high as the exhaust temperature, with the secondary heatsink reaching 85°C at the worst-case 110% load. Running a PSU under such conditions for an extended period of time would almost certainly result in a dead power supply, but it did manage to survive our short-term stress test.
Up to medium load, the power supply is extremely quiet registering less than 20dB(A). Higher loads result in increased fan speed and noise levels, and in our stress chamber we reach a maximum noise level of 28dB(A) at 80% of load (350W). However, 28dB(A) is still very quiet so in terms of noise levels users should be very pleased with Corsair. The problem is, low noise levels and low fan RPMs contribute to the relatively high heat sink temperatures. We are not sure if Corsair really tested this unit under stressful conditions - maximum load and a high ambient temperature - and we would caution users against using any of these power supplies in such an environment. Under more sedate operating conditions, however, the Corsair 450VX performs extremely well.
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zeroidea - Wednesday, November 7, 2007 - link
The Antec PS featured in this article is currently on sale at staples.com for $30.http://www.staples.com/webapp/wcs/stores/servlet/S...">Link
SilthDraeth - Wednesday, November 7, 2007 - link
I know it falls outside of the 450Watt max, but it is still below the 500 watt barrier. I just bought the psu for a midrange system I built my mom, I know it works well, but I don't have the ability to test everything.One can wish right?
Noya - Tuesday, November 6, 2007 - link
If you look around (buy.com), the Corsair 450vx can be had from $51-61 pretty regularly, and at that price it's untouchable. I must say I've had one for about two months and haven't had any problems with it.smthmlk - Tuesday, November 6, 2007 - link
Can we have a full list of caps in each unit? Noting the primaries is nice, but what about the others? Thanks.Talcite - Tuesday, November 6, 2007 - link
Thanks for finally putting up O-scope readings, it's quite nice to see them. One thing I'm concerned about though is the lack of explication or analysis.For example, is the entire o-scope range 200mV in the 12v readings or is it one division? Also, there's a number of strange spikes in all the o-scope readings. I'm pretty familiar with the 450VX o-scope readings (mostly from other sites) and I haven't noticed any spikes of that nature in their readings. It probably isn't, but is the equipment faulty?
Thanks for putting the readings up anyways though, they're a nice addition.
Super Nade - Tuesday, November 6, 2007 - link
Those strange spikes are probe noise. If the probe is coupled incorrectly, you will see this artifact. This cold be due to any number of factors like EMI for instance. Following the ATX guideline on using 0.1 uF output coupling caps will minimize this to a great extent.MrOblivious - Tuesday, November 6, 2007 - link
You have to look at the sampling time on the readings to compare between sites. Different sampling times will make the traces appear a bit different.phaxmohdem - Tuesday, November 6, 2007 - link
I just recently built a rig for a buddy using a Thermaltake PurePower (or ToughPower.. can't remember) 480W Unit and it works like a champ powering a Core2 Quad Q6600 CPU, 2GB RAM, 2HDD's, two Optical Drives, 8600GT, TV Tuner and a few fans. (Wish I knew about the Corsair PSU when I spec'd that system out).But yeah, Unfortunately most people equate Watts to overall quality.... not unlike the MHz war of days gone by. Power supplies are one of the hardest components to convince people to spend extra on for some reason. FFS, electricity is kind of the basis of the whole dam computer!
Eventually it ends up as "Oh well. Go ahead and get that 600W $30 power supply and let me know how that goes for ya. I could use a good laugh, and don't say I didn't warn you."
strikeback03 - Tuesday, November 6, 2007 - link
Maybe Anandtech should go ahead and list the weight of each PSU. That has long been used as an estimate of quality.jonnyGURU - Tuesday, November 6, 2007 - link
Not any more. Topologies have changed to the point where you can have very light quality units and very heavy crap. Weight is NOT a factor.