How hot should a 450W psu be?

[faye]

Hi, actually how hot should a 450W psu be?

i bought a GTR 450W, a pretty high reputation psu in hong kong.

this psu is actually hot.

 

[AsiLuc]

I don't think there's a "should be" actually. Cooler is of course better, but if it works well it's cool right?
My TruePower 430 get's pretty hot but works fine, so you'll be okay.

 

[HardWarrior]

Have you called tech support to see what they have to say about the issue?

 

[faye]

no not yet,

but seems like the only thing that is producing the heat is the psu. even hotter than the cpu, much much hotter.

 

[EarthwormJim]

It's pretty normal for a PSU to get hot. I think you need to better define hot by the way. Do you mean the air coming out of the PSU is warm (like what would come out of a moderate heater), or is scalding hot (as in steam).

 

[Zepper]

Some PSUs run their fans way too slow or they may not be working at all. I decided that the Delta PSU that came in my new case was running too warm (and I couldn't hardly feel any breeze from its fan), so I hooked that fan up for manual speed control rather than the thermal sensor to which it was connected. The PSU and the whole computer run much cooler now.
.bh.

 

[faye]

the air from the psu is hot and the psu itself is hot too.!

i am now finding a way from the motherboard to test the temp.

how?

 

[Zepper]

There is no way to measure the PSU temp unless you have one of those front panel controllers with its own temp probes. Or you could use a fever or digital oven thermometer if you have one.
.bh.

 

[NeoPTLD]

How do you quantify "it's hot"? There's nothing to worry about unless you see smoke, smell something or it gets hot enough to burn you.

 

[Ken90630]

Hi, Faye:

I know this is going off on a tangent a little, but I thought I'd point out that a 450-watt PSU for the system you have is way, way more than you need. It's beyond overkill.

If you do a wattage calculation for your modest system, you'll find that a 300-watt PSU will be MORE than enough for you, with gobs of headroom to spare. In fact, a 250-watt PSU will do the job for what you have. (But I don't recommend that as there aren't many [or any?] truly high-quality 250-watt PSUs out there.)

A quality 300-watt PSU from PC Power & Cooling, Seasonic, Antec or SilenX, just to name a few, will not be "hot" in the way you're describing at all. They'll probably be quieter too. You might check the efficiency rating spec of your PSU -- some PSUs typically have poor efficiency ratings, which means they don't convert a very good percentage of the incoming AC power into DC power (for your components), and the "wasted energy" is released as heat. (That's a superficial explanation, but close enough for discussion purposes.) Efficiency ratings are tricky as some mfgrs cite ratings achieved at 220V (European voltage!) and/or only at full load (which never occurs in a PSU), but a rating of somewhere between 65% and 74% (for 120VAC) is the ballpark a PSU should perform at nowadays. Anything less than that and it's gonna be wasting a lot of energy and giving off heat ... and running up your electric bill more over time as well.

I don't mean to denigrate your PSU, as I'm not familiar with GTR PSUs at all. Just giving you some food for thought. I assume you've checked to see that its fan are functioning properly and that the voltage switch (if it has one) on the back is set correctly?

 

[faye]

Hi Ken90630,

oh, a modern system uses about 260 to 280watt.. i know i have plenty of room, that's y i am so worry about y it still gets hot. I've try the 450w on a P3 system, and i don't feel any heat at all.. Ya, no heat at all. but once i put it back on my P4 Prescott, it is a total story.. It won't burn me, but don't feel very comfortable to have a "very hot" device sitting next to my cpu.

my GTR psu has 2 fans, and has PFC approved(does it mean anything to you?)


and have so many QC test pass labels sticked on the side.

 

[Ken90630]

Okay, I must have been hallucinating last nite 'cuz I could have sworn your system was a P3 when I was composing my post. Since your post doesn't indicate it was edited (!), I can only apologize for not paying closer attention to your system's components.

Having said that, a 350-watt PSU will still do the job for you and a 300-watter would probably suffice too (as long as you're not running everything at the same time). But, that's a side issue as you want to determine the problem with your current 450-watt PSU.

Based on what you describe in your last post, it sounds like maybe some of the extra heat from the P4 is being drawn into the bottom of the PSU and, in turn, blown out the back. Now, obviously a P4 (particularly a Prescott) is gonna be hotter than any P3, but I wouldn't think that alone would cause an excessive or huge increase in the amount of exit heat from your PSU. And if you had a CPU fan or heatsink problem, you'd be experiencing other problems besides a hot PSU, so I'll assume both of those are working correctly.

I dunno. It's hard to say what the problem is without seeing it. Does your PSU have temperature-sensitive fans? In other words, fans that speed up or slow down depending on the internal temperature of the PSU? I suppose it's possible that the temperature sensing could be malfunctioning and maybe the fans are running at their slowest speed all the time. This is kinda unlikely, but possible. You also wanna be sure your case is well ventilated and that you have more fans blowing air out of the case than just the 2 fans on the PSU. You should have at least one fan exiting hot air out the back or the side of the case, and I've read where a blowhole-type vent on the top of the case helps cool the case better with hot CPUs like the Prescott P4s at high clock speed. You have two hard drives and a 9800 video card too, so those are gonna be generating some heat as well.

It's possible that everything's working fine and this is just the way that particular PSU runs with a P4 system. As long as you can't fry an egg on it or burn your hands, it's probably not gonna pose any significant problem. I'd just go with your instinct on this -- if it bothers you that much, call tech support and/or see if you can exchange it for a new one.

Oh, and PFC stands for power factor correction. Without going into a long technical explanation, it's a good thing and is generally associated with decent efficiency ratings. There's active PFC and passive PFC; active works best. If your PSU has active PFC, odds are its efficiency is within acceptable bounds.

As for the QC labels, sometimes that stuff is more for marketing than anything else. A component can usually pass most of those "tests" as long as it's working and not catching fire. It's better to have them than not have them, but they often don't mean that much.

I'm by no means the world's biggest expert on PSUs. Some of the other guys here at Anandtech.com know far more than I do about them. You might post your question again on Saturday (when the forums get seen more) if you don't get the answer you're looking for right now. Good luck.