Is my PSU not powerful enough?

October 23, 2009 at 16:10:46
Specs: Windows XP

I need your advice before purchasing a new PSU. I've recently upgraded my system and have a quad core Athlon processor and a ATI 4800 series video card. The system works fine except when I play games in which intermittently the system keeps rebooting itself. I also find that if I add an extra device into a USB socket etc, sometimes the mouse won't work.

I'm pretty sure, or at least I'm hoping that this is a PSU fault, either not enough wattage under duress, or failing altogether? I know the box on my video card states that it requires 350 watts, so I guess that doesn't leave much room for anything else.

Before I purchase a new PSU I would like your advice, thanks.

See More: Is my PSU not powerful enough?

Report •

October 23, 2009 at 17:32:00
I would consider looking at event logs and maybe dump logs before I bought any hardware.

Sure, anyone and their brother can sell a so many watt power supply and it may or may not be enough no matter what is stated on the box. Each line has only so much current. About the only correct way is to use a resistive load on a power supply. This is beyond most home and soho users ability and most tech shops too.

About the best choice is to see what you have. I can't believe you have a 350 watt right now. Then look online for pages to calculate how many hard drives and motherboard and cpu and such so you can plan if your PS is too small already.

Playing to the angels
Les Paul (1915-2009)

Report •

October 24, 2009 at 00:46:23
Thanks, how do I do event logs btw. Sorry I forgot to mention my PSU is 450 watts, and I have it a long time.

Report •

October 24, 2009 at 03:57:26
I've looked at the events log and it all sounds gobbledygook to me.

Report •

Related Solutions

October 24, 2009 at 05:35:51
I've looked back at posts dating to 2003 and people were concerned about 350 watt then, so I'm pretty sure this is the problem.

Report •

October 24, 2009 at 06:44:20
"Sorry I forgot to mention my PSU is 450 watts"

Just telling us the wattage doesn't mean a thing. There are $15 450W PSUs & $100 450W PSUs & everything in between. We'd need to see the brand name & the amperage specs.

Report •

October 24, 2009 at 10:09:20
Model LPK9
wattage 450
orange 25 amps
red 35 amps
white 0.5 amps
yellow 18 amps
blue 0.8 amps
purple 2 amps

Report •

October 24, 2009 at 10:40:12
Ah I forgot to mention my PSU was only cheap probably cost me about 15 pounds

Report •

October 24, 2009 at 11:49:26
orange = +3.3v
red = +5v
yellow = +12v

Those are the only ones we need to be concerned about. It appears you have an INNOVATOR LPK9 450W ΑΤΧ Switching Power Supply. I couldn't dig up much on it...most of the links are in Russian. But 18A on the +12v rail isn't much these days, especially for a system with a high end graphics card. If you do decide to upgrade the PSU, get a unit with a single +12v rail of at least 30A...more would be better. And buy a decent name brand unit.

I doubt you're in the US, but here's an example of a good unit - Corsair 550W with 41A on the +12v:

Report •

October 24, 2009 at 13:48:42
Thanks that's great help, really appreciate it. You're right I live in England.

To be honest I was pretty sure the PSU was not up to the job, because the problem only seems to occur when the system is under duress with 3d games, but I was worried because if it wasn't that I wouldn't have a clue to the problem.

Time's finally catching up with me I suppose. I've never considered the PSU to be a problem at all in the past, it was always the least of my concerns. I just used to bungle together an upgrade, stick in any old PSU I could find, and had no problems, but I appreciate current PCs require a hell of a lot more oomph.

By the way, will I get better performance as well with a better PSU or does that make no difference?

Report •

October 24, 2009 at 13:51:24
One final question, is it just me or are people starting to find more and more problems now with PSUs? Because like I said I hardly gave any thought to them before.

Report •

October 24, 2009 at 18:27:51
It's not just you Scott. Most people believe any psu will do the job and they buy accordingly..."cheaper is better".

No one wants to spend $75-125 on a power supply and most don't. But, they'll sure let go of that money for a video card.

When problems occur due to these cheapo psu's, it's the last thing they think of. jam mentioned $15 psu's; they're available because all the $5 power supplies are used up by oem and other system builders.

Your problem is typical of an underpowered (cheapo or quality) psu. For example, a HD4850 will want about 6a of +12v power for 2D but, demands about 13a for 3D. The difference of 7a (about 85 watts) is certainly enough to cause your problems.


Report •

October 25, 2009 at 03:45:27
I see what you mean problem is it's affording it, I already went over budget trying to put the rest of the system together, but I'll see what I can do.

Report •

October 28, 2009 at 17:52:42
I bought a new PSU but unfortunately I only had a budget of £20 so I had to get another cheap one off Ebay I'm afraid. It is an 850 watt and has 4X 20 amps on the 12 v connector. I tried to take your advice as much as I could on my budget.

It seems to be much better and I played for hours without a restart but then just as I was starting to put it to the back of my mind and relax, poomph, it does it again. Hopefully it's a rare event.

If it only does it occasionally I can live with that, but it is frustrating when I thought the problem was gone forever.

Report •

October 28, 2009 at 18:00:08
Am I right to assume that the 20 amps on the 12v is still causing the problem? If it is I'll have to put up with it until i can afford a quality PSU.

Report •

October 28, 2009 at 18:39:05
probably the PSU, but check ur temps. An overheating CPU or GFX could cause some problems to. Since it crashs durring games it may be heat related. My gfx gets up to 48 under load and idles at 35c. Much over 55 coudl cause problems.

Intel DP35DPM Socket 775 Motherboard
Intel Quad Core Kentsfield 2.4Ghz Q6600 CPU
Ultra 4096MB PC6400 DDR2 800MHz Dual Channel 2X1024

Report •

October 29, 2009 at 10:02:45
No the temps are fine. In the past I've found overheating just causes my system to freeze ironically, not restart itself.

Anyway I've just played through a 45 minute battle in Empire Total War and it was ok, so hopefully the problems won't persist.

Report •

Ask Question