Tech Support Guy banner
Status
Not open for further replies.

Power Supply Question

2K views 27 replies 10 participants last post by  musikman1 
#1 ·
Hi, im about to start buying a new mobo and possibly another video card, and was wondering if my current PSU, a SilverStone Zeus ST56ZF 560W, can handle the HDDs listed in my system specs, the processor listed, the video card currently listed, and the new mobo? Right now, that's my main concern, but i am also curious to know if that PSU might be able to handle that new load with two GeForcr 9800GT cards SLI'd together?

the mobo:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813186152

Also, i really appreciate the help, so thanks! :p
 
#2 ·
not on a 560W even if it runs and by some miracle you have the right cables its likely to cause your computer to crash under heave use, or possibly under volt and destroy components!

I would imagine that each one of those 9800's takes 250- 300W so that would leave you with 60W- 0W for every thing else.
 
#4 ·
Ok well i think i'll wait until i can upgrade my psu to go with the new video cards then. Thanks for the help, i had a feeling it wouldn't be a good idea and i don't really want to chance it, i'll upgrade to either a 700W or 800W psu and just stick with this one while i keep using the card i have right now.
 
#6 ·
Ok, im kinda bumping this thread because i've changed my question a bit, but it still concerns power supplies. Im pretty much ready to buy a new power supply, i definitely want an 800 Watt PSU but i don't really know much about the brands out there so i'd really appreciate some suggestions, especially with modular cabling!

thanks again everyone for the help!
 
#7 ·
Of the 3 best brands (at least in my opinion) PC Power & Cooling, Corsair and Silverstone I believe the one the link leads to is the only one you will find with 700 or above watts that is modular design.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817256036

Unless you specifically need to go modular, I would stay away from it and just go with one of the power supplys I mentioned with a large single +12v rail.
 
#8 ·
Just a word of advise; foxconn builds fine boards however their MIR are non-existent. I would NOT count on receiving the rebate.
Next I would recommend going with an amd chipset board rather than an nvidia board. When you use third party chipsets, you add an extra layer of complexity to the issue.

IMO this foxconn board would be a better choice.
 
#10 ·
Im pretty much ready to buy a new power supply, i definitely want an 800 Watt PSU but i don't really know much about the brands out there so i'd really appreciate some suggestions, especially with modular cabling!
Hey phaedrus55,

I just went through this identical search and destroy mission, combing the forums for recommendations and such from around the 'net.

One thing that I found out, is that with the new microprocessor based PSU's, one can over-spec the PSU, BUT the PSU will still ONLY draw the power the unit requires.

IE: Your system requires 750W to run.. Both an 850W and a 1000W will draw roughly (given required overhead) the same amount of wall current to run the system. Just because it is a 1000W PSU, for example, does NOT mean it will constantly draw 1000W from your house current.

Given that, I preferred to err by getting 1000W units vs. 850W, as my system was "rated" (by several of the online power apps) to need 790W. I'm NOT an electrician, I'm a musician, and all of my life in any sort of audio equipment, it was always important to build in "overhead" space to allow for unexpected pops and spikes when calculating needed power. Also, at least as far as audio amps go, a 2000W amp running at 800W is going to run VERY cool, whereas an 800W amp running at 800W would run very hot on a consistent basis.

Just my .02, I prefer to allow myself the overhead space. I use an APC 3KW UPS, and it reports the computer using max 820W to date (by the logs the UPS keeps), so I haven't yet "drawn" the full 1000W that my PSU is rated. Your mileage may certainly differ! :)

RECOMMENDATIONS:

From my running around and reading countless reviews and forums, I settled on the following:

Antec Quattro 850W - 1000W (80 Plus Certified)
Enermax Galaxy 1000W (85 Plus Certified)

I installed the Quattro 1000W in my office computer, and the Enermax in my RAID server. Both are CPU controlled, have modular power attachments, which (in my experience) came in the box with WAY more wires than needed, making them very versatile for a multitude of options.

NOTE: Both came with TWO GPU power cords, and for the main power, they had both the 4 and 8 conductor secondary CPU power cables.

I paid $149.00 for the Antec Quattro 1000W (on sale at Microcenter), and the Enermax ran me $259.00 at newegg.

Both have been installed and running since last November and I have had absolutely no problems with either power or internal heat problems. Both systems I'm running in a 4U rackmount case, both with the CPU heatsinks that came with the CPU, and I added at least one additional fan aimed at the GPU.

FAN NOTE: I found some neat fans (cannot remember the brand) that were mounted on rear slot covers, so they installed in an unused slot in the back of the case, and they came with a 3 pin header that works with my motherboards.. They cost a princely $5 each!

I wish you luck with your PSU search!

Rick
 
#12 ·
You're right Lee, best to get some hard figures.

Another PSU calculator (free, even for advanced features):

http://www.antec.outervision.com/

It helped me find my max load with 8 internal SATAII HDD's, 1GB Video, 4GB DDR2 RAM, Quad processor, three optical drives and a few other gadgets, internal header card reader, fans, 12 USB 2.0, 2 1394's, A/D audio + soundcard, etc.. That's how I landed on the 1KW PSU.

I had tried an 850W PSU, but it was running warm, the 1KW (both the Antec and Enermax) run REALLY cool with just the stock CPU cooler and 3-4 fans in the rackmount case (4U).

All my best,

Rick
 
#13 ·
Nice calculator musikman I hate it when somebody ask a ? about PSU and everbody and they brother jump in and say that they need a 800-1000-1500 watt supply the next
thing is you will have to put a biger line into your house just to run your computer HAHA
 
#14 ·
Heya Lee,

RE: Watching the folks guestimate power requirements..

Yeah, I'm with you! Believe it or not, the shop that built my server with all those SATA drives in it, delivered it to me with an Antec Neo650W PSU. I had to open it up before booting it the first time to install a CDR drive and a card reader, and saw (to my horror) the power supply.

Being the naturally cynical soul that I am (pit orchestra work will do that to you..), THAT'S when I went hunting on the net for a PSU calculator and actually came upon three of them online.. They all calculated within 30W or so my stuff, but the antec was more "elegant," or easier to use with more updated options..

That's when I found out that my brand new server with the 650W PSU needed 705w+ to run!

And "accidental brilliance," I happened to walk into Microcenter here in Cincinnati, and they had the Antec Quattro 1KW's for $149 on sale. They had two left on the shelf, so I bought both and threw one "on the shelf" because I'd NEVER find another at THAT price! It was one of those in-store sales not advertised on the net..

Cheers!

Rick
 
#15 ·
actually the 9800GT requires 500W a Imagen it uses 250 - 300W
 
#17 ·
cool is that under full load?
 
#18 ·
ok thanks a lot for all the responses to this thread, and that calculator definitely came in handy. right now i have 560 W but i think i still want to upgrade just a little because i don't want to chance over-using my current PSU but after considering all the replies in this thread i might look at the 700-750W power supplies...
 
#19 ·
#21 ·
Hey Darkwade,

RE: Are they under full load?

That was the very question I was asking.. Nowhere on either the nVidia or Antec site were there any illustrations yea or nay..

Phaedrus,

Good luck with your search! DO try to give yourself some headroom so you don't heat up the inside of your box!

Regardless of what brand or model you have in mind, check and see if it has an 80 Plus or 85 Plus certification. This is an independent group that certifies PSU's (and other things) as to the guaranteed energy efficiency. This means that you'll get the most computing power for the least wall power.. lower electric bills are a wonderful thing!

http://www.80plus.org
 
#22 ·
ok well thanks for the suggestions, i've decided on the Antec 750W PSU, and i'll definitely take that advice musikman1 and leave as much headroom as i can, and the modular cabling ought to help keep spare cables out of the case. i'll mark this thread solved once i get the part and make sure it works alright, so thank you everyone for the help and info, it really helped a lot!
 
#23 ·
The 9800GT are 105 watts / 8.75 amps under max load, per card... just for those that were asking.

I would go with a single rail unit over that Antec. Something like the Corsair 750TX

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006

With a multiple rail power supply, you have to make sure you distribute your power wisely, otherwise you can end up with not enough amps on a rail that needs it. Antec claims is had 25 amps max load on each rail, for the four rails.. which can be misleading. That is a max number for a particular rail, but it does not represent the total amps the power supply can output.

You find amps by taking wattage and divide it by a factor of 12, in other words, for every 12 watts = 1 amp.

The real numbers for that Antec are 56 amps total load across all four rails, so if you were to evenly distribute the rails, it means only 14 amps each.. not the 25 amps. Yes, you can put 25 amps on one rail, but that additional 11 amps will be subtracted from the other rails. A 750w power supply has 62.5 amps to play with, but you have to keep in mind that +3.3v and +5v rails have power set aside that is dedicated for those rails only. So in that Antecs case, they have 6.5 Amps or 78 watts set aside.

See how this could become problematic when building a system that requires more power then an average computer?

With a single rail unit, it will give the wattage/amps where you need it, without losing (or wasting) any available power on any given rail. That is why when someone is building a higher-end system that requires multiple graphics cards and such, I recommend a single rail unit.

Just thought I would throw that out there for you to consider.

Ans, as an aside... the money spent on two 9800 GT's would be better spent on a more powerful single card solution... you can get more performance out of a newer single card then two of the 9800 GTs for about the same price.... unless you want to do SLI.
 
#25 ·
Alright, well, i'll have to update my specs, cuz now i've got everything running perfectly! I've got that Antec model installed and it's working great, as well as adding an additional HDD, a Seagate 1TB SATA which is just awesome!

Thanks a lot for the help everybody, you have no idea how much of a difference it made!
 
Status
Not open for further replies.
You have insufficient privileges to reply here.
Top