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View Full Version : Fried PSU - need another

yyzyvr
Oct 22nd, 2008, 08:42 AM
I've got an older system that I inherited from someone else. After upgrading some of the parts, the PSU seems to have conked out. Maybe someone can help suggest how powerful a replacement I need?

The computer has been shutting off after prolonged use (which I thought was just due to overheating). The last time this happened, there was some crackling and light smoke coming from the PSU unit, almost like a little electrical fire. Having left the case open after the previous shutting-off incident, I could could see this go down and immediately unplugged it from the grid. I have no way of knowing for sure whether this was already happening before I got the PC or something I caused with my upgrades.

The setup is an Intel d915gux motherboard and a P4 3.4 GHz or 3.6 GHz CPU. The BIOS told me this is one of the later P4s that supports HyperThreading and 64-bit operation. The CPU has a large Zalman-brand "2-ball bearing quiet cpu cooler" fan mounted on it. This fan is powered directly from the PSU, not through the motherboard. The PSU is an "Allied" brand switching power supply, max 300W. The model # is AL-B300ATX.

When I got it, the PC did not have a dedicated video card or a hard drive so I added the following:
* Hitachi DeskStar SATA300 500GB drive
* EVGA GeForce 8600GTS 256MB

Does this new stuff need more power than the 300W PSU can give? Could that cause it to almost start burning? When I replace this power supply unit, how much wattage should I aim for? Right now, I'm thinking either 450W or 500w - needs enough power to eventually OC the CPU quite a bit, keep the HD listed above, and upgrade the video card later on to something more powerful. Where in Vancouver can I get one for a good price?
googoo
Oct 22nd, 2008, 10:48 AM
http://www.newegg.ca/Product/Product.aspx?Item=N82E16817371005

Use the $20 off coupon, and it works out to about $40 delivered

code "canadagrandop20"

Brent
Warlock
Oct 22nd, 2008, 07:06 PM
Link,
eXtreme Power Supply Calculator Lite v2.5 (http://extreme.outervision.com/psucalculatorlite.jsp)
evanx
Oct 22nd, 2008, 07:13 PM
http://www.newegg.ca/Product/Product.aspx?Item=N82E16817371005

Use the $20 off coupon, and it works out to about $40 delivered

code "canadagrandop20"

Brent

Good deal there for your situation. Make sure it has the right number of cables you require.
syuzh
Oct 22nd, 2008, 07:47 PM
Stop by NCIX and grab a nice 350/400w PSU by Seasonic. The average price is about $40 on sale. You don't have to wait for shipping and it is much better quality. New sale starts tonight, so you may have to wait until tomorrow.
KorruptioN
Oct 22nd, 2008, 08:03 PM
Link,
eXtreme Power Supply Calculator Lite v2.5 (http://extreme.outervision.com/psucalculatorlite.jsp)

This isn't a great link, as it only spits out a final wattage rating without taking into account how many power supplies have their amps spread out over the different outputs. "400W" can come in many flavours, as you should know.

The fact that they charge for their "better" calculator is more reason you should stay away from these guys.
yyzyvr
Oct 22nd, 2008, 10:19 PM
Yeah, I was already going to look at the upcoming NCIX and Anitec flyers to see if any good ones come up on sale.

I'm still unsure whether to get 450W-500W or go even higher (ie 600W-650W) for future upgrades and overclocking. I think anything less than 400 is not enough of an upgrade.
LeeBear
Oct 23rd, 2008, 12:54 AM
Yeah, I was already going to look at the upcoming NCIX and Anitec flyers to see if any good ones come up on sale.

I'm still unsure whether to get 450W-500W or go even higher (ie 600W-650W) for future upgrades and overclocking. I think anything less than 400 is not enough of an upgrade.

Don't base your buying decision based solely on wattage. Your system doesn't require that much wattage, it requires a nice stable (brand name) power supply. Not to mention power supply wattage ratings are usually not comparable unless they tell you how its rated. Most higher quality PSU (Seasonic, Corsair, etc) rate the wattage as the sustain power at a temperature of 50 degrees celsius (the typical operating temp of the PSU) while no name PSU will rate at the "peak" wattage at a temp of 25 degrees celsius (typical room temperature). It may not seem like much but the "peak" rating is usually about 100W higher then what the PSU can really put out over any useful period, and as the temp goes up the PSU becomes less efficient, at about 50 degrees celsius a PSU puts out only about 75% of its power. What does all this mean? Well basically it means a "good" 350W power supply would have a rating of around 550W if it was rated the same way as a "no name" PSU. That is why everyone is saying a 350-400W Seasonic power supply is way more then your system even requires.

-LeeBear
yyzyvr
Oct 23rd, 2008, 11:13 AM
Don't base your buying decision based solely on wattage. Your system doesn't require that much wattage, it requires a nice stable (brand name) power supply. Not to mention power supply wattage ratings are usually not comparable unless they tell you how its rated. Most higher quality PSU (Seasonic, Corsair, etc) rate the wattage as the sustain power at a temperature of 50 degrees celsius (the typical operating temp of the PSU) while no name PSU will rate at the "peak" wattage at a temp of 25 degrees celsius (typical room temperature). It may not seem like much but the "peak" rating is usually about 100W higher then what the PSU can really put out over any useful period, and as the temp goes up the PSU becomes less efficient, at about 50 degrees celsius a PSU puts out only about 75% of its power. What does all this mean? Well basically it means a "good" 350W power supply would have a rating of around 550W if it was rated the same way as a "no name" PSU. That is why everyone is saying a 350-400W Seasonic power supply is way more then your system even requires.

-LeeBear

Thanks for the breakdown. I think the Seasonic 400W is it. Not on sale at NCIX right now, but still reasonable at $50.