CPU Power Supply question

Glenn Chan · February 18th, 2004, 01:27 PM

Google search for "power supply calculator"
First link: http://www.jscustompcs.com/power_supply/

I also said which programs will monitor voltages:

Quote:

Anyways, power supply really shouldn't be a problem for you. If you experience problems, download Motherboard Monitor or use your motherboard's monitoring utility to check your voltages to see if they're within 5% of what they're supposed to be.

David Ho · February 18th, 2004, 04:23 PM

Rob, it is 350W.

Rob Belics · February 18th, 2004, 04:59 PM

No worries, mate. Load it up.

David Ho · March 2nd, 2004, 01:21 PM

Regarding the PCI cards, do I check that too with the motherboard? I mean, my mobo has already the PCI cards listed including the network card, USB, FireWire, etc... When calculated, total PSU consumption minimum was 380 W! I don't think that's really accurate... but perhaps I should invest in a 400 or 450W.

Rob Belics · March 2nd, 2004, 04:17 PM

You say those pci cards are already on the motherboard. Do you mean they are built into the motherboard? Or are these actual, physical, cards that can be unplugged from the motherboard?

If these features are built into the motherboard, it will use less power than if they are seperate plug-in pci cards.

Glenn Chan · March 2nd, 2004, 06:38 PM

Hmm it seems like a lot of power supply calculators differ in the numbers they use. There are also various numbers you could use. For hard drives, they take a lot of wattage to start spinning and then use less energy once they're up and running. Most sites list hard drives as between 5-15W, while it can take up to 30W to start up.

http://www.seagate.com/docs/pdf/datasheet/disc/ds_barracuda7200.7.pdf
On seagate's site, the 7200.7 (7200rpm PATA/SATA drive) takes up to 12.5W while writing or seeking. Other manufacturer's drives probably take more wattage... but probably not the 25W the jscustompcs.com site suggests. I think the numbers there ,may be a bit exaggerated since I've seen a few other calculators that give lower numbers.

350W should be good enough for most people. The worst case is when you are running a Pentium3.2C/Prescott/AMD64 processor, top of the line video card, and multiple hard drives.

Glenn Chan · March 2nd, 2004, 07:23 PM

There's an excellent thread about power supplies at http://episteme.arstechnica.com/eve/...5&m=8490995295. It has brand recommendations, because off-brand power supplies probably have their wattage rating fudged.

There's another calculator over at
http://takaman.jp/psu_calc.html?english

David Ho · March 2nd, 2004, 09:19 PM

Rob, they are built into the motherboard already.

I am not noticing any problems at the moment (or ever from the beginning). Everything is running fine, no crashes, stable -- then I guess I have enough power. :)

Rob Belics · March 2nd, 2004, 10:51 PM

If all that is built into the motherboard then the power requirements for the whole motherboard are all you need to look up. You don't need to look at individual cards at all.

Disk drives, in fact all mechanically driven electrical devices, use the most power at start up. So that number is the only one you should use. If a drive only runs on, say, 5 watts while running but needs 10 watts to spin up, then your power supply better be able to deliver that 10 watts on demand. Therefore, you just add 10 watts to your power requirements.

According to my Asus P4T-E manual, a typically loaded system consumes 230watts max. A heavily loaded system is 300w max. But they don't define what a system is.

February 18th, 2004, 04:23 PM	#17
David Ho Major Player Join Date: Nov 2003 Location: Los Angeles, CA Posts: 354	Rob, it is 350W. __________________ "Everyone has a photographic memory. Some just don't have film."

March 2nd, 2004, 01:21 PM	#19
David Ho Major Player Join Date: Nov 2003 Location: Los Angeles, CA Posts: 354	Regarding the PCI cards, do I check that too with the motherboard? I mean, my mobo has already the PCI cards listed including the network card, USB, FireWire, etc... When calculated, total PSU consumption minimum was 380 W! I don't think that's really accurate... but perhaps I should invest in a 400 or 450W. __________________ "Everyone has a photographic memory. Some just don't have film."

March 2nd, 2004, 09:19 PM	#23
David Ho Major Player Join Date: Nov 2003 Location: Los Angeles, CA Posts: 354	Rob, they are built into the motherboard already. I am not noticing any problems at the moment (or ever from the beginning). Everything is running fine, no crashes, stable -- then I guess I have enough power. :) __________________ "Everyone has a photographic memory. Some just don't have film."

February 18th, 2004, 04:59 PM	#18
Rob Belics Major Player Join Date: Apr 2003 Location: St. Louis, MO Posts: 581	No worries, mate. Load it up.

March 2nd, 2004, 04:17 PM	#20
Rob Belics Major Player Join Date: Apr 2003 Location: St. Louis, MO Posts: 581	You say those pci cards are already on the motherboard. Do you mean they are built into the motherboard? Or are these actual, physical, cards that can be unplugged from the motherboard? If these features are built into the motherboard, it will use less power than if they are seperate plug-in pci cards.

March 2nd, 2004, 06:38 PM	#21
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	Hmm it seems like a lot of power supply calculators differ in the numbers they use. There are also various numbers you could use. For hard drives, they take a lot of wattage to start spinning and then use less energy once they're up and running. Most sites list hard drives as between 5-15W, while it can take up to 30W to start up. http://www.seagate.com/docs/pdf/datasheet/disc/ds_barracuda7200.7.pdf On seagate's site, the 7200.7 (7200rpm PATA/SATA drive) takes up to 12.5W while writing or seeking. Other manufacturer's drives probably take more wattage... but probably not the 25W the jscustompcs.com site suggests. I think the numbers there ,may be a bit exaggerated since I've seen a few other calculators that give lower numbers. 350W should be good enough for most people. The worst case is when you are running a Pentium3.2C/Prescott/AMD64 processor, top of the line video card, and multiple hard drives.

March 2nd, 2004, 07:23 PM	#22
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	There's an excellent thread about power supplies at http://episteme.arstechnica.com/eve/...5&m=8490995295. It has brand recommendations, because off-brand power supplies probably have their wattage rating fudged. There's another calculator over at http://takaman.jp/psu_calc.html?english

March 2nd, 2004, 10:51 PM	#24
Rob Belics Major Player Join Date: Apr 2003 Location: St. Louis, MO Posts: 581	If all that is built into the motherboard then the power requirements for the whole motherboard are all you need to look up. You don't need to look at individual cards at all. Disk drives, in fact all mechanically driven electrical devices, use the most power at start up. So that number is the only one you should use. If a drive only runs on, say, 5 watts while running but needs 10 watts to spin up, then your power supply better be able to deliver that 10 watts on demand. Therefore, you just add 10 watts to your power requirements. According to my Asus P4T-E manual, a typically loaded system consumes 230watts max. A heavily loaded system is 300w max. But they don't define what a system is.