Newbie Power Question

Stubborn · 03-02-2006, 07:57 AM

I just recently purchased a new PC and I'll be upgrading it Friday with a GeForce 7800 GT and a Creative XFI Fatal1ty but I'm not sure if I need to upgrade the PSU. The specs for the stock PSU are as follows:

Hipro 300-Watt 24-Pin ATX Power Supply

General Features:
300-watt
One (1) 9-inch 24-pin ATX power connector
One (1) 4-pin Aux power connector
Five (5) 4-pin molex power connectors
One (1) floppy power connector
Two (2) SATA power connectors

Power Specifications:
300-watt max output
+3.3V, 18.0A
+5V, 25.0A
+12V, 19.0A
-12V, 0.8A
-5V, 0.25A
+5Vsb, 2.0A
I don't quite know what all of this really translates to because I just started my learning about this stuff 5 minutes ago when I read the PSU 101 sticky.
I know the amperage is what I need to worry about but it got me wondering becaues the new video card says it requires 350w and this thing I have is only max 300.

I'll be running logitech's Z-5450 speakers along with this new 7800 GT card so I really don't want to dick around with a weak PSU.

I'd appreciate any opinions on this matter and please talk to me like the newbie that I am. The most I've ever done is upgrade some RAM.

mrjack · 03-02-2006, 09:00 AM

"Minimum of a 450 Watt power supply"

That's what it says on Newegg when I checked the requirements of a GF7800GT. So your current PSU isn't good enough for that card and I would recommend getting a PSU with atleast a total of 25A on the +12V rail. Atleast, more would be better.

Stubborn · 03-02-2006, 09:07 AM

Quote:

Originally Posted by mrjack

"Minimum of a 450 Watt power supply"

That's what it says on Newegg when I checked the requirements of a GF7800GT. So your current PSU isn't good enough for that card and I would recommend getting a PSU with atleast a total of 25A on the +12V rail. Atleast, more would be better.

That's what I figured. Thanks for the help. 450 Watts on a video card is some serious business. I didn't even have that much pushing two JL 12w0's. Yikes.

Stubborn · 03-02-2006, 09:04 AM

I think I have it figured out. What I'm looking for it the 12V rail for my video card, I guess....and what I have is 12x19=228. That's not enough. So I should be looking for something that is 12v and around 30A. But then what about the speakers? I'll need some serious power for them too, I assume, and then all the 5v and 3.3V for the little guys. So basically I need about 800watts, right........ or do the sound cards act as an amp allowing me to run a smaller rail on it?

**ceewi1** · 03-02-2006, 09:53 AM

Quote:

But then what about the speakers? I'll need some serious power for them too, I assume, and then all the 5v and 3.3V for the little guys. So basically I need about 800watts, right........ or do the sound cards act as an amp allowing me to run a smaller rail on it?

You do NOT need 800W. The speakers do not draw their power from the computer. That is why they are plugged into a power point. All that the sound card provides is a signal voltage. A 450-500W power supply with a strong +12V rail would be fine, take a look at PSU101 for some recommendations.

Stubborn · 03-02-2006, 10:16 AM

Ah, sweet. I knew the wireless speakers were plug-ins, but I thought the rest were run off the PC (just like regular old speakers). That helps a ton, thanks.

I think I have one last question. If I go with something that has twin rails, like 12V1@18A, +12V2@18A for example, would I somehow plug both into my video card, or do I plug only one and make sure the other one remains unused?

**ceewi1** · 03-02-2006, 11:12 AM

Only one of the rails gets used powering the video card. Do not worry that the single rail does not meet the requirement of the video card, as the requirements you read are not what the video card itself requires, but what a system using that video card should require (and the other rail will be used powering other components).

If your PSU has dual rails, one rail will power the CPU & mobo, while the other will power everything else.

stishdr · 03-02-2006, 08:01 PM

I got a question then, if my psu has 2-6 pin connectors for PCIe, and 2 12v rails, what does the other 12v rail do that's not plugged into mobo?

03-02-2006, 07:57 AM	#1 (permalink)
Stubborn New Member Join Date: Mar 2006 Posts: 8	Newbie Power Question I just recently purchased a new PC and I'll be upgrading it Friday with a GeForce 7800 GT and a Creative XFI Fatal1ty but I'm not sure if I need to upgrade the PSU. The specs for the stock PSU are as follows: Hipro 300-Watt 24-Pin ATX Power Supply General Features: 300-watt One (1) 9-inch 24-pin ATX power connector One (1) 4-pin Aux power connector Five (5) 4-pin molex power connectors One (1) floppy power connector Two (2) SATA power connectors Power Specifications: 300-watt max output +3.3V, 18.0A +5V, 25.0A +12V, 19.0A -12V, 0.8A -5V, 0.25A +5Vsb, 2.0A I don't quite know what all of this really translates to because I just started my learning about this stuff 5 minutes ago when I read the PSU 101 sticky. I know the amperage is what I need to worry about but it got me wondering becaues the new video card says it requires 350w and this thing I have is only max 300. I'll be running logitech's Z-5450 speakers along with this new 7800 GT card so I really don't want to dick around with a weak PSU. I'd appreciate any opinions on this matter and please talk to me like the newbie that I am. The most I've ever done is upgrade some RAM.

03-02-2006, 09:00 AM	#2 (permalink)
mrjack VIP Member Join Date: Jul 2005 Location: Finland Age: 18 Posts: 2,595	"Minimum of a 450 Watt power supply" That's what it says on Newegg when I checked the requirements of a GF7800GT. So your current PSU isn't good enough for that card and I would recommend getting a PSU with atleast a total of 25A on the +12V rail. Atleast, more would be better. __________________ Intel Core 2 Duo E7200 @ 3.45GHz \| MSI P7N Zilent 2x2048Mb OCZ Titanium 800MHz DDR2 Western Digital Caviar 160Gb SATAII Samsung Spinpoint F1 320Gb SATAII Western Digital Caviar 500Gb SATAII Samsung Spinpoint F1 750Gb SATAII MSI NX8800GT OC 512Mb Creative Sound Blaster X-Fi Xtreme Audio Antec Truepower Trio 550W Windows Vista Ultimate 64-bit Last edited by mrjack; 03-02-2006 at 09:04 AM.

03-02-2006, 09:04 AM	#4 (permalink)
Stubborn New Member Join Date: Mar 2006 Posts: 8	I think I have it figured out. What I'm looking for it the 12V rail for my video card, I guess....and what I have is 12x19=228. That's not enough. So I should be looking for something that is 12v and around 30A. But then what about the speakers? I'll need some serious power for them too, I assume, and then all the 5v and 3.3V for the little guys. So basically I need about 800watts, right........ or do the sound cards act as an amp allowing me to run a smaller rail on it? Last edited by Stubborn; 03-02-2006 at 10:32 AM.

03-02-2006, 11:12 AM	#7 (permalink)
ceewi1 Moderator Join Date: Dec 2005 Location: Melbourne, Australia Age: 22 Posts: 5,418	Only one of the rails gets used powering the video card. Do not worry that the single rail does not meet the requirement of the video card, as the requirements you read are not what the video card itself requires, but what a system using that video card should require (and the other rail will be used powering other components). If your PSU has dual rails, one rail will power the CPU & mobo, while the other will power everything else. __________________ CPU: Core 2 Duo E6600 / MOBO: Gigabyte 965P-DS3 / GPU: Gigabyte HD4870 RAM: 2GB G.Skill F2-6400CL4D-2GBPK / HDD: 2TB Total HDD / PSU: Antec NeoPower 480W Cheap PSUs - 2% of system costs, responsible for 28% of system deaths As Sealed Stick was removed, lost or damaged, it shall be out of warranty validity. - The "Warranty void if removed" sticker on numerous CoolerMaster PSUs. Useful PSU Guides Last edited by ceewi1; 03-02-2006 at 11:32 AM.

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03-02-2006, 10:16 AM	#6 (permalink)
Stubborn New Member Join Date: Mar 2006 Posts: 8	Ah, sweet. I knew the wireless speakers were plug-ins, but I thought the rest were run off the PC (just like regular old speakers). That helps a ton, thanks. I think I have one last question. If I go with something that has twin rails, like 12V1@18A, +12V2@18A for example, would I somehow plug both into my video card, or do I plug only one and make sure the other one remains unused?

03-02-2006, 08:01 PM	#8 (permalink)
stishdr Silver Member Join Date: Feb 2006 Location: oshkosh, wisconsin Age: 22 Posts: 169	I got a question then, if my psu has 2-6 pin connectors for PCIe, and 2 12v rails, what does the other 12v rail do that's not plugged into mobo?