BleepingComputer.com: Trouble choosing power supply wattage

I already have all my parts:
Seagate Barracuda 7200.12 ST3500418AS Hard Drive - 500GB, 7200, 16MB, SATA-300, OEM
Dual Channel 4096MB PC6400 DDR2 800MHz Memory (2x2048MB) - RAM
AMD Phenom X4 9750 Quad Core Processor - 2.40GHz, 4MB Cache, 3600 MT/s FSB, Quad-Core, Socket AM2+, OEM Processor (0.25 lbs)
Asus M4N78 PRO Motherboard - Socket AM2+, Geforce 8300, ATX, HDMI, SATA, Gbit LAN, Hybrid SLI (1.24 lbs)
Thermaltake V3 Black Edition Mid Tower Case - ATX, Micro ATX, 120mm LED Fan, 4x 5.25 Bays, 5x 3.5 Bays (13.4 lbs)

Note that for the time i am using the integrated video (Geforce 8300). However i do plan to add a graphic card in the future, since i'm on a budget it's going to have to wait. Now i have sent my mind on getting a 500 Watt power supply, will this be sufficient?? Help

Hello Zeppelin 707

I believe for that board it is recommended to use 750 Watt power supply. Below are a couple of links that contain a power supply calculator to help you out a little.

http://extreme.outervision.com/psucalculatorlite.jsp

http://educations.newegg.com/tool/psucalc/index.html

Hope this helps you out

Nauni

Yeah, a 750W PSU should meet your system's current and future requirements.

Here's a good one: Corsair 750TX ~ $110

750W seems a little overkill to me, I'd have recommend a Corsair HX520 or 620 if you're going to be over-volting

What if he decides to make use of the Hybrid SLI and thrown in a few more upgrades?

This post has been edited by ReviverSoft: 23 December 2009 - 03:38 PM

I thought Hybrid SLI was rarely used in gaming systems where a full SLI system (two discrete GPU's) would work best. Not all Nvidia cards support Hybrid SLI. At any rate, I think the best way to determine which PSU you need is to take the recommended wattage from the graphics card manufacturer and add 100W onto it. If you want to use SLI/Crossfire, take the amount of power needed for those and add 100W onto that. Find a GPU you think you will be getting and use that to determine your wattage. Since the motherboard you chose has only one PCI-Express X16 slot, you won't be doing SLI. I'm not sure which specific GPU's work with Hybrid SLI, but I do know that not many in the GTX 2xx work with it. If it is anything like ATI's take on Hybrid Crossfire, it isn't meant for the high-end market. One of the best discrete GPU's on the market is the Radeon 5870 which requires a 500W PSU. I suggest getting a 600W or greater PSU.

I think that alot of people do not realise that watts are not all when it comes to PSU's.
you also have to worry about the current on each rail of the PSU
Generaly you will max out the watts on a single rail before you manage to get anywhere close to the load spec'd in the product description (usually the 12v rail as that is the one which the GFX cards, and processors pull on the hardest)
Whats more the configureation of the rails in the PSU also matters For example:

The EPS 12V standard which my old Thermaltake Toughpower 700W (non modualar x4 12v rails) PSU is spec'd at is not great with heavy duty graphics machines. (its not SLI certified either for the following reason)

The reason being that in the EPS spec (for 12v x4)the PCIe connectors shair their rail with other bits an pieces (possibly molex connectors who knows) SLI certification requires PCIe connectors on a seperate rail

A coirsair HX620 is fullly certified for SLI
you may want to refer to http://techreport.com/articles.x/13271/11 for more information about the coirsair PSU.

If you are not willing to go with that here is a list of reliable PSU's which work well:
http://www.overclockers.com/forums/showthread.php?t=589708

This post has been edited by Totty: 23 December 2009 - 06:44 PM

Totty, on Dec 24 2009, 04:50 AM, said:

Useful link.
The Corsair 750TX does feature on the list.

People should also be aware of the modular and non-modular types of PSUs.
Modular types, offer detachable power cables to reduce clutter by using only those that are necessary. Ideal for small, cramped PC cabinets.

There is no doubt that the Corsair 750TX is a great PSU (i've used it myself in an SLI build for a client)
But
For the above system it is overkill.

Oh well, figured a hungry crossfire/sli setup in addition to his current system should consume quite a bit and still leave room for more upgrades, if the Corsair 750TX was installed.

Guess the Corsair HX650 (MODULAR) could be a second option.

This post has been edited by ReviverSoft: 23 December 2009 - 07:13 PM

If the motherboard allowed for SLI, then the 750W unit would have been the best for future upgrades using high-end GPU's. However, that motherboard only has a single PCI-Express X16 slot, which lowers the ceiling for needed watts. All of Corsair's PSU's are good, though it is a good idea to have a certified PSU if you're going to be running with multiple GPU's. Reviver's second option, the HX650, is an excellent choice. Other brands you can consider are Silverstone, OCZ, and PC Power.

Even if he was using dual 5850's and wanted to add a few more hard drives or a more power hungry CPU a HX620 would have been more then adequate for his power needs.

Seeing as he is not going to be over volting, running tripple SLI/crossfire with that motherboard there really isnt much point in going for the TX750.

Even an HX520 will run a crossfire set-up with a pair of 5850's, it will just be a bit noisy due to load levels.

IMHO there is no such thing as over kill in a power supply. Get as much as you need and more. Spending $$$$$$$$$$$ of dollars on a video card or cards and lots of RAM worrying about another $ 25.00 to get lots more power supply just don't add up to me. Any quality power supply that you don't have to work very hard puts out a smother voltage, runs cooler and last longer. As many have posted, it gives you the ability to add things without worrying about power. Lots of +++++++++++++ and no ---------------- for just a few bucks more.

Why get a PSU rated for 100W more then you will ever need? He could go through several system upgrades with a 600W PSU including an SLI/Crossfire setup. That and higher watt PSU's tend to be less power efficient.
By the post he put above He's aiming at what a maximum of 1 discrete graphics card?
He could run 5 Hard drives and 6 fans off of a 620W PSU and not even worry about stressing it..

There is also the point that if you take a DMM with you and actually measure the current draw from your computer you will realise that even under load the draw will probably be less then 300-350W Even with a crossfire setup.

What matters more is the rating on the 12v rails as I have said before.

This post has been edited by Totty: 24 December 2009 - 09:21 AM

What matters more is the rating on the 12v rails as I have said before. I agree with this statement. Most likely no one knows at this time what might be added to this computer not even Zeppelin 707. It can't hurt to have lots of power.
http://www.tomshardware.com/reviews/nvidia,1189-40.html is a good place to take a look at power usage of just GForce cards. from 130w to 343 w. If one would clock the cards along with extra cooling one would need lots of power for a clock and the extra cooling. Some cards have two power supply ports so they get the power they need. To much power supply can't hurt but just enough or not enough will cause problems.