240watt power supply enough?

[jonathonsunshine]

Howdy yall. I am building computer for a friend, real basic, out of layaround parts.

AMD Athlon™ XP 3000+ (Barton Core)
Asus A7S8X-MX motherboard (on board vid/sound/ethernet) (full mobo details at bottom of page)

2 IDE HD's and 1 DVD (maybe 2)


I have a 240watt power supply floating around. Do you think this will be sufficent ? It was able to power this computer to the extent of installing windows with only 1 hard drive and 1 dvd installed without any problems.

I'm just worried that with 2 harddrives and 2 dvd roms over the long term it might do some damage....








Motherboard specs
Model #: A7S8X-MX
Warranty:
12 months
Manufactures:
Asus
Weight(kg):
0
Product link:
none

Product Description
Motherboard Features
System Type PC
Chipset SiS741GX
Form Factor Micro ATX
Data Bus Speed 333 MHz

Processor
Compatible Processors Sempron, Athlon XP Processor Socket Socket A
Maximum Processors Supported 1

Slots
Provided Slot Types 2xPCI, Processor, Memory, 1xAGP 8x
Slot From Factor Socket A, DIMM 184-pin

Memory
Installed Ram Size 0 MB
Maximum Supported RAM Size 2 GB
RAM Technology DDR SDRAM

Sound
Sound Output Mode 5.1 channel surround

Cables & Connections
Interface Provided RS-232, IEEE 1284 (EPP/ECP), Input, VGA, Floppy interface, Ethernet 10Base-T/100Base-TX

General Features
Software Included Drivers & utilities, ASUS PC Probe

General Product Info
Also known as ASUS, ASUSTeK COMPUTER A7S8X-MX, ASUS A7S8X-MX

Manufacturer Part No. A7S8X-MX

[Sharktooth]

240W is not enough. maybe it starts but when the CPU is stressed it will behave weirdly.
also keep in mind 240W is the nominal value... effective power is less than what is declared as nominal.

[CWR03]

You didn't mention video card, which can "make or break" a PSU rating.

[Sharktooth]

he did. it's onboard.

[RunningSkittle]

Is it enough to power it? Yes.

However keep in mind that PSUs are most efficient at ~50% load. And your really pushing your 5v and 12v rails with multiple drives.

Upgrade to at least a decent 450w psu.

[Blue_MiSfit]

I don't think it's a big deal - at all.

I ran much more than that for a long time on a 300W PSU... I had a Barton 2500+ running at 2.4 GHz, 4 hard drives, a Radeon 9800 Pro, a sound card, 2 optical drives, and all that jazz. No problems at all.

Hard drives don't use that much power, and optical drives only use some when they're being used. Simply having them connected isn't going to affect your draw. Even so, they use at most 5-10W.

That being said, Sharktooth brought up a good point. Just because this PSU is rated for 240W doesn't mean it will actually deliver that much. What are true specs? How many amps on +12V and +5V? Socket A processors draw a fair amount off the 5V IIRC.

~MiSfit

[dat720]

As long as the sum of the components don't exceed the total power handling of the power supply you will be fine, as a reference my old PC which was a HP DC7600 (sush, i know it was free) had a 240w supply and was fine with 2x SATA HDD's 1x DVD Samsung Burner, 3.5gb Ram Pentium D CPU and a ATI HD2400Pro Video Card, oh and a Fusion HDTV Lite TV Tuner.

[Shinigami-Sama]

I should work, but I wouldn't trust it
any variation on the input power(pluggin in a vacuum ect) could cause an undervolt
I'd say a 350watt would do the job

[foxyshadis]

By far the most important bit of information that was left out was the maker of the PSU. If it's a good one, it'll suit perfectly - that setup is unlikely to ever go over 160W, perhaps even 120W. If it's a bad one, it may die in a month or kill parts slowly.

I have no idea why people are so suspicious about power supply wattages when it's the manufacturer that matters more.

[Sharktooth]

uhm... barton 3000+ is power hungry.
old hard drives may eat up more current than newer ones... expecially if they're maxtor.
however anything above 300W (from a decent manufacturer) should be good.
if you plan to add a videocard that needs external power (or just for gaming), aim for 400+ Watts (always from a decent manufacturer)...

[dat720]

any variation on the input power(pluggin in a vacuum ect) could cause an undervolt

How do you figure that? Voltage regulators are designed to handle fluctuating input's, the only time a regulator will go under its spec'd output is if the input rail goes close to what the output is, and seens the highest rail in a PC is 12v, the 110/240v input has a long way to drop before a under volatage situation could occur!

The bigger worry would be if a device in the PC draws more current and pushes the PSU over its spec'd limit's which could cause the rails to go low.

[Shinigami-Sama]

How do you figure that? Voltage regulators are designed to handle fluctuating input's, the only time a regulator will go under its spec'd output is if the input rail goes close to what the output is, and seens the highest rail in a PC is 12v, the 110/240v input has a long way to drop before a under volatage situation could occur!

The bigger worry would be if a device in the PC draws more current and pushes the PSU over its spec'd limit's which could cause the rails to go low.

I've had it happen to me a few times with similar hardware
the 250W just could not handle it, ofc it was some no-name PSU that came with the case
which could very well be the case with his PSU

[dat720]

I live on a rural property in Regional Australia, our power supply is quite average and the sub stations quite often have brown/black outs....

None of my Computers/TV's/STB's/Console's anything electrical ever have any problems, even with a air conditioner (which draws upto 30amps) and water pump (again upto 20amps) turning on and off that causes the lights to noticably dim!

If a 30amp current draw does not drop enough voltage to cause problems with PSU's then a let's say 1000w vacume cleaner that draws about 5amp's is not going to cause any significant problems!

The bigger problem would have been with the PSU itself being faulty!!!

[Sharktooth]

good PSU have good capacitors...
cheap PSU dont...
good and big capacitors will mitigate the problems A LOT.

[dat720]

The quality of a PSU does not cause problems like that, the condition of it does!

If a PSU does that because of its cheap build price then it shouldn't even be on the market and no doubt is a breech of several laws!

[Sharktooth]

well, there are a lot of cheap and bad quality PSUs around... most of them are cheap chinese products.

[CWR03]

The quality of a PSU does not cause problems like that, the condition of it does!

If a PSU does that because of its cheap build price then it shouldn't even be on the market and no doubt is a breech of several laws!
The problem is that there are no governing bodies that examine PSU ratings and set guidelines that they must meet. You never know until you push one if that 240 watt rating is continuous or a peak only sustainable for a few seconds. I replaced a 430 watt "cheap" PSU with a very expensive Antec unit of the same rating, and that PC's performance improved dramatically under load.

[RunningSkittle]

well, there are a lot of cheap and bad quality PSUs around... most of them are cheap chinese products.

luckily most of these cheap components are easily identifiable simply by looking at the caps.

[Sharktooth]

yep but some PC builders use them...

[dat720]

CWR03 no your right, but there are laws concerning devices that can be plugged into a power point, if it doesnt meet specifications and if it is clearly as dodgy as SharkTooth claims then this would have been picked up during certification.

Good quality 400w PSU's can be had for AU$60 anyone that spends $20 or $30 on a PSU is just asking for trouble, and i stand by my statement that if a PSU is resetting itself due to minimal voltage drops then it is clearly faulty and should be returned to where it was purchased or just replaced!

[jonathonsunshine]

Hello yall

(i am the original poster incase anyone has forgotten after reading all the above)

The PSU manufacturer is IPEX. It came with a case that I inherited from work (IE they were throwing away). It was originaly running a PIII 866mhz, with a broken harddrive (no doubt why they threw it out). I dunno if IPEX is a good brand or not but it had a very sturdy feel to it, (i know that isn't very technical but on the other hand I have handled PSU's that will warp in your hands like a cardboard box).

I ended up not using it, and instead putting a (definitly cheap) 400watt.

Thanks for all your responses.

[Sharktooth]

Uhm... IPEX... malaysian product... definatly cheap.

[dat720]

jonathonsunshine dont know if you figured this out yet (if its the reason you chose not to use it) but a poswer supply for a P3 system will most likely not work in a Athlon/P4 system as the P4 power supplies have a additional 12v 4pin conenctor that the P3 supplies dont.... just for future reference.

[Inventive Software]

I got caught out with that when I suggested a similar upgrade for a family member. £20 and a PSU later, the computer's still healthy, and used intermittently as a games server.

These days, I'm very wary of generic PSUs that have high Wattage ratings, and there's a generic 600W one in a computer that I'm considering replacing with a branded one, but I'm unsure which brand to go for. Can anybody recommend good brands to look out for?

[RunningSkittle]

List is a little dated, but still very relevant.

http://www.xtremesystems.org/forums/showthread.php?t=108088

I bought a Corsair 520HX and will never look back :)

[foxyshadis]

Look for an 80 PLUS certified PSU if you really want a quality one that'll minimize your total electricity use.

[jonathonsunshine]

jonathonsunshine dont know if you figured this out yet (if its the reason you chose not to use it) but a poswer supply for a P3 system will most likely not work in a Athlon/P4 system as the P4 power supplies have a additional 12v 4pin conenctor that the P3 supplies dont.... just for future reference.

The mobo I was using didn't have that plug, the 4pin power plug

[dat720]

Good thing i said most likely then huh.....

[jonathonsunshine]

Good thing i said most likely then huh.....

Hey! Defensive much ? I didn't mean anything by it...

[dat720]

I wasn't being defensive!

I was just implying that i'm not always right :)