Time to replace my PSU?

[nsiderTalon]

Alrighty. So I currently have a three year old Coolmax 400W. The fan has been getting louder and stuff recent, which is almost enough to make me replace it. It's powering this right now:

Intel Core 2 Duo E4600 @ Stock
ASRock 775Dual-VSTA
ATI X1900XTX
2GB OCZ Gaming RAM
250GB SATA HDD
Creative X-Fi Xtrememusic

I would think that my X1900XTX is underpowered because the recommended PSU is 450W or more, and mine is only 18a on 12v. Not to mention that my PSU doesn't have native PCI-E x6 pin support, I'm using a 4-pin to 6-pin adapter. My system runs fine though, I've run BF2142 for several hours straight without a problem. So what happens if your GPU's not getting enough power?

As for replacements, I've been looking at the Corsair 450W and the Antec Neo Power 500. Is either better than the other? Do I need more power than that?

 

[PurdueRy]

If the GPU doesn't get enough power it will either glitch and you will see artifacts or your system will shut down(more likely)

Both of those power supplies are fine replacements. Go with whichever you can get cheaper.

 

[mpilchfamily]

If you are under powered there is a number of problems that can occure. Your system can start to exibit many problems that seam like there are problems with other parts. This can also lead to curruption of your HDD. If you continue long term use of the PSU then it could fail possibly killing other components.

 

[Zap]

There are also GPUs that will underclock themselves if they don't get enough power, so stuff works "properly" but not as fast as it can.

As for the Corsair 450W versus Antec Neo 500W, depends on if you want modular or not, and if you want the larger fan. If neither matters, then just take the cheaper one. Either will power your current system just fine. Will you be upgrading your video card anytime soon? If so, then see what amount of power and what kind of PCIe plugs are on a video card that you may consider, and purchase your PSU based on that.

 

[nsiderTalon]

I might grab a HD 4870 when they go down to under $100. Actually, assume I will do that.

What about Antec's EA500? If all of these are just about the same I might just go with it. It would be the Seasonic version.