How Much Wattage Do I Require?

[Incorruptible]

Hello, I will be building a computer soon and I need help determining how much wattage I need.

CPU- AMD FX-6300

Motherboard- ASUS M5A97- http://www.tigerdirect.com/applicati...040&CatId=7248

RAM- 8GB DDR3 1600MHZ- Havent picked specific ram

HDD- 1TB Sata, 7200RPM http://www.tigerdirect.com/applicati...660&CatId=2459

SSD-Not sure yet but looking at SATAIII http://www.tigerdirect.com/applicati...113&CatId=5300

Graphics card- 7850 http://www.tigerdirect.com/applicati...619&CatId=7387

Network card-Possibly a network card but not sure.

One DVD Rom drive

Case-Not sure but most likely will have one 120mm LED fan OR 120mm LED fan + 120mm fan.

Peripherals- Keyboard and mouse most likely wireless

I have used 3 different calculators with two calculating I require 320 watts and another at 400. The CPU alone is suppose to require 95 watts and the minimum for my graphics card is 500 so how much wattage would I require for this setup?

Here are the calculators I used

http://www.extreme.outervision.com/PSUEngine

http://www.thermaltake.outervision.com/Power

http://images10.newegg.com/BizIntell/tool/psucalc/index.html

 

[Revolution 11]

Let's say you use 400 watts for a system (probably not). A 500W power supply is plenty for your system, including all system and power inefficiencies.

For example, I came up with 466W required when including 2 120mm case fans, fan controller, Radeon 7870, SSD, an additional PCI-E x8 card, and all system components at 100% load and CPU at 100% TDP (capacitor aging at 30%). This shows a very rare power situation that you will never achieve.

- FYI, the Thermaltake calculator is a exact copy of the Extreme PSU calculator, thus the same wattage. Both calculators are conservative in their estimates, you rarely need that much power.

 

[lehtv]

For example, I came up with 466W required when including 2 120mm case fans, fan controller, Radeon 7870, SSD, an additional PCI-E x8 card, and all system components at 100% load and CPU at 100% TDP (capacitor aging at 30%). This shows a very rare power situation that you will never achieve.

- FYI, the Thermaltake calculator is a exact copy of the Extreme PSU calculator, thus the same wattage. Both calculators are conservative in their estimates, you rarely need that much power.

Uh... The Thermaltake/Extreme calculator does not calculate how many watts you'll be pulling. It estimates a recommended PSU wattage, and it leaves A LOT of margin between that number and the real power consumption.

A typical non-overclocked gaming PC with a 7850 graphics card will consume about 200 watts when gaming. With the GPU and an FX CPU properly overclocked, 250W or more.

 

[Soulkeeper]

I have a similar system, just with a different cpu.
Chance are that system will pull somewhere around 350-400W from the wall(depending on psu efficiency) when everything is fully loaded.
Getting a 400W psu would be borderline imo.
You'd be better off getting something like a 600W unit to be safe if it's in your budget.
ie: peace of mind

Just to note my gold seasonic 400W runs my quad + 7870 all day fine.
But if I throw in an extra addon card the pulls around 90W the system will reboot from time to time (when kill-a-watt hits about 430W from the wall).

 

[lakedude]

At stock clocks a 500 will be plenty and a 400 would be OK so long as you don't plan to torture test the system 24/7 with programs like Furmark or OCCT.

I've got a very similar setup with a HD 7850 except I run an i7-3770s. In game my system only pulls 165 watts. Running BOINC CPU only projects pulls about 110 watts and running both CPU and GPU projects pulls about 185 watts. The OCCT "power supply" test maxes the system out at 260 watts.

Your CPU will pull a bit more but I bet you don't go over 350 watts at stock clocks. Your CPU's TDP is only 30 watts higher than mine.

Now if you start overclocking all bets are off. If you are going to OC get a 500 minimum.

Are you going to OC and what are you going to be doing with your computer exactly?

 

[Incorruptible]

At stock clocks a 500 will be plenty and a 400 would be OK so long as you don't plan to torture test the system 24/7 with programs like Furmark or OCCT.

I've got a very similar setup with a HD 7850 except I run an i7-3770s. In game my system only pulls 165 watts. Running BOINC CPU only projects pulls about 110 watts and running both CPU and GPU projects pulls about 185 watts. The OCCT "power supply" test maxes the system out at 260 watts.

Your CPU will pull a bit more but I bet you don't go over 350 watts at stock clocks. Your CPU's TDP is only 30 watts higher than mine.

Now if you start overclocking all bets are off. If you are going to OC get a 500 minimum.

Are you going to OC and what are you going to be doing with your computer exactly?

I will not be overclocking. My pc will be mainly web browsing/youtube/watching movies and gaming (BF3). I will probably have the pc on for 12 hours a day maybe less and the rest on standby

I was thinking 500 watts should be plenty and still safe and keep me within the budget. I think a 600 watt PSU would hurt the electric bill.

 

[Ayah]

Power supplies only deliver as much power as is required by the system. Using a 600W (of the same fractional efficiency curve as the 500W) would only draw slightly more power, probably not enough to be noticed.

So if a 600W (same or superior design) to the 500W you're looking at is cheaper, grab it.

 

[crazymonkeyzero]

A 400W+ good quality PSU should be sufficient, like the Corsair CX 430. If you OC 500w. Also fyi, gpu manufacturer power requirements are inflated to account for the number for flaky psus out in the market claiming high wattages but delivering abysmal performance. So buy a good quality psu from a brand like corsair, seasonic, antec and you'll be fine.

 

[lakedude]

Yep, yep

A 600 is not necessarily going to draw more power than a 500, in fact it is possible that a 600 would draw less than a 500 depending on the efficiency of each model and where on the power curve the load hits. Power supplies tend to be most efficient in the middle of their band, generally being less efficient at both low and high loads. Said another way a 500 is going to be most efficient @ around 250 watts and a 600 is going to be most efficient @ around 300.

Also the rating makes a difference.

better/more efficient - 80 plus Platinum > Gold > Silver > Bronze > 80 plus > is not 80 plus -worse/less efficient

Surfing is going to be @ under 150 watts (mine bounces around between 50 and 100 watts while surfing with new pages peaking out close to 100 but static pages plunging below 60).

Movies hold pretty steady in the mid 60ies on my rig, yours will be a tad higer.

BF3 is going to be your biggest load by far. I don't play BF3 but I hear it loads up the CPU pretty good. My guess is that it would load up my system to around 200 watts and perhaps load your system to 250 or so.

Based on your guesstimated projected loads I'm going to say that a 450 to 550 would be best, with a 400 or 600 being perfectly fine, especially if you find a deal or find one that has a better 80 plus rating.

 

[Incorruptible]

Yep, yep

A 600 is not necessarily going to draw more power than a 500, in fact it is possible that a 600 would draw less than a 500 depending on the efficiency of each model and where on the power curve the load hits. Power supplies tend to be most efficient in the middle of their band, generally being less efficient at both low and high loads. Said another way a 500 is going to be most efficient @ around 250 watts and a 600 is going to be most efficient @ around 300.

Also the rating makes a difference.

better/more efficient - 80 plus Platinum > Gold > Silver > Bronze > 80 plus > is not 80 plus -worse/less efficient

Surfing is going to be @ under 150 watts (mine bounces around between 50 and 100 watts while surfing with new pages peaking out close to 100 but static pages plunging below 60).

Movies hold pretty steady in the mid 60ies on my rig, yours will be a tad higer.

BF3 is going to be your biggest load by far. I don't play BF3 but I hear it loads up the CPU pretty good. My guess is that it would load up my system to around 200 watts and perhaps load your system to 250 or so.

Based on your guesstimated projected loads I'm going to say that a 450 to 550 would be best, with a 400 or 600 being perfectly fine, especially if you find a deal or find one that has a better 80 plus rating.

Thanks, I will be going for a 500 watt PSU and if I can find a 600 watt for a similar price I will go with 600 watts.

 

[BrightCandle]

XBitlabs has a 6300 and a Asus Deluxe board pulling 166 Watts at load with 8GB of RAM. Lets call it an even 170W, the CPU is 95W TDP and the RAM is about 20W and so 45W is about right for a motherboard depending on how its kitted out.

A hard drive will pull up to about 8W, although its going to be well below that most of the time.

The SSD is a little under 5W full load.

The 7850 is a 130W TDP part.

A DVD drive is peak about 25W.

2x 120mm fans assuming relatively reasonable speeds are about 1W each.

Total = 170 + 8 + 5 + 130 + 25 + 2 = 340W

Now in addition to that its important to understand that PSU's only deliver good efficiency between 20-80% of their load. Outside of those ranges and efficiency drops off, so its important not to make the PSU too close to maximum or indeed to big such that the idle consumption drop too far out of the efficient zone.

Given that your minimum is realistically 425, ie 340 / 0.8 as we want the maximum load of the system to be at the 80% mark. Anything from 425W to about 500W will be reasonable, although I would argue more for the 500W so you have a bit of extra room incase you want to add more peripherals and your additional network card etc. But you don't need to go any higher than 500W and you shouldn't go below 400W. Try to get a reasonable brand rather than the cheapest one, they are more efficient and more importantly they can actually deliver the power they say they can, whereas many cheap brands will die or worse when pushed near their limit and they are usually noisier.

 

[lakedude]

That is some fancy math BC!

Glad we agree on the 500.

Care to do my rig? BIOSTAR TZ77XE3 LGA 1155 Intel Z77, i7-3770s, 120GB SSD, 2TB "green" HD, HD7850, 16GB RAM @ 1600, DVD burner, no OC, Antec NEO ECO 520C 520W 80 PLUS Certified Active PFC Power Supply.

The most I've been able to make it draw is about 260 watts with OCCT "power supply". Maybe if all the drives were spinning it could go a bit higher?

 

[evanesce]

Get the best psu you can afford, that way in the future you will be covered should you someday require more power. I've failed at this, so maybe you can learn from my mistake