PSU Requirements

[elux]

Hi Guys
I am new to this forum, so I thought I would pass this info on to you, it was sent to me by gigabyte tec support after I was having probs with a new mo board and processor, just shows that its worth considering additional power requirments for new/additional equipment.

Underated PSU?

Do You have enough Power?
Quick Check! approx power consumption

Latest Motherboards=40watts

Fans (each)=9watts or 0.5amp eusing the +12v line

Athlon Xp & Intel CPU above 1800 =90watts or 7.5amp using the +12v line

CDROM / DVDROM"s each take =30watt or 2.5amps using the +12v line

Hard Disk Drives each take=30watt or 2.5amps using the +12v line

AGP latest 8x =up to 80watts

Here is a sample system config.

Sample Config=
You can check your voltage rail amp ratings on the Side of your PSU.
+12v line components only...= max 18.5amps

CPU=1800 7.5amps
2*HDD= 5.0amps
1*CDRom= 2.5amps
1*DVD= 2.5amps
2*Fan= 1.0amp

PSU 300-400 will only run a basic athlon 1.6.Or a entry level P4. using the incorrect power supply will cause lots of problems including slower fan speeds and blue screening system shut downs. And will eventually cause complete failure of system.
Get an AMD approved PSU around 500-550w with a absolute minimum of 18amps on the +12v line.. for the GA7***** range (mid 20’s -35) recommended for future upgrades.
Also the P4 if used with a lot of hard drives/space will also need a high end power supply with a good +12v supply. Again suggest a 550w for future upgrades.
I believe that www.pcsuppliesuk.co.uk tel 01229 877577( have some very good prices on these.

Each component with a motor uses approx 1.5 – 2.5 amps on the +12v line ie fans, hard drives, floppy drives, and Graphics cards. Most CPU’s use around 8- 11 amps themselves!!!. Also High speed memory PC3200 (400) needs a lot of power.

Hope this is of some use to you. Elux

 

[HammerBot]

LOL. a 500 or 550 W PSU is waay too much for the majority of systems out there. Further you calculations are flawed.
What FAN uses 9W?!?! This is outragerous, such a fan would make your case fly. All fans I have seen uses max 2W (80 mm).
Those drive current consumptions are too high and some of it are also taken from the 5V. Most harddrives I have seen uses about 0.8A on the 5V rail and 1A on the 12V rail (total of 16W). I don't know about raptors, but some really high speed drives may use 20W or perhaps 25W but this is very uncommon. Check what is printed on the drive. CD/DVD drives definitly does not use this amount of power.

If someone out there wants to make an estimate, check <A HREF="http://www6.tomshardware.com/howto/20021021/powersupplies-02.html" target="_new">this table</A>. This is a <i>much</i> better first guess of the power consumption. As a second guess, check what current consumption is printed on the drives and use that in you calculations.

<i><b>Engineering is the fine art of making what you want from things you can get</b></i>

 

[jihiggs]

30 watts for a hard drive? that seems pretty high to me.

wpdclan.com cs game server - 69.12.5.119:27015
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[elux]

First they are not my calculations that are flawed, read the 1st paragraph, this is a reply from Gigabyte Tec support I agree they do seem high. You might also check le <A HREF="http://www.jscustompcs.com/power_supply/" target="_new"> this table </A>

 

[HammerBot]

You might check it out yourself. All the numbers you posted are higher than what's shown in that table. Further, your link doesn't provide any clue as to which rail the power is drawn from.
Did Gigasuck actually tell you you all that crap? Including the power drain on the 12V rail? Some of that is completely wrong!

<i><b>Engineering is the fine art of making what you want from things you can get</b></i>

 

[pIII_Man]

anyone who buys a 500w psu for a desktop system is out of their mind. Here's a scenario (true)...

Freind wants to upgrade system...he is using a 233mhz gateway pentium II system with a 200w psu. He wants me to hook him up with the cheepest upgrade while mantaining a fair amount of performance...

i ended up slapping a

Nf7-M (Nforce IGP)
3x 128 dimms (only used cause got em for free)
Athlon xp mobile 2400+ (barton core runs 1.93ghz @1.45v w/ 45w tdp)
existing 40gb 7200rpm wd drive
existing floppy
existing cdrom
existing cdrw

Overclocked that cpu to 2.2ghz @ 1.65v, with old 200w psu, psu's voltages are rock solid, fluctuating less than +/- .05v on all rails...

Granted the psu was of very good quality...but it still can't be putting out more than 300w, it shows no signs of stress as the air comming out of it is not that warm. So honestly i really think anything over 350w for a standard system is over kill, if you are running a lot of stuff (ie big raid arrays) a good 400w psu is all you really need. If you buy a shitty psu, then maybe you need 500w to match the quality of brands like enermax and fortron, but honestly you dont need all that much. The only reason why huge psus are being really hyped up is that there is a lot of [-peep-] on the market.

If it isn't a P6 then it isn't a processor
110% BX fanboy

 

[Crashman]

Power supplies are supposed to be rated at max continuous power, but most are rated at peak load. How long they can hold that peak is up to the manufacturer, one company might rate a power supply at 500W because it can hold that load for .005 seconds, while another might rate the same supply at 300W because it can hold that load for 7 minutes per 10 minute cycle (aka 70% duty cycle). And another might rate the same supply at 250W continuous.

Without overcurrent protection, those supplies are capable of outputting that peak load for .005 seconds without being reset. A Fortron 250W unit might supply the same amount of power (250W continous) but reset at 300W because it HAS overcurrent protection. Which is what makes the Fortron 250W better than the 500W cheapy, it won't blow out! Also name brand supplies such as Fortron offer better filtering by using larger and more numerous capacitors and inductive coils.

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