First build, question about PSU.

[Surfari]

So I'm building my first PC and have 0 clue how much capacity a PSU can safely run at. I am debating between PSU's in the range of 500W-650W power supply at the moment but am not sure which would be suffice. I do not plan to SLI or Overclock anything but I may add in another SSD and will most certainly be adding a second screen down the line. So my question is which wattage would you guys recommend?

P.S. I'm kinda leaning towards the 500W if the system can safely run with that because the price point on it after a mail in rebate is half the cost of a 550W.

PCPartPicker part list: http://pcpartpicker.com/p/7y3NVn
Price breakdown by merchant: http://pcpartpicker.com/p/7y3NVn/by_merchant/

CPU: Intel Core i5-4690K 3.5GHz Quad-Core Processor
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler
Motherboard: MSI Z97-Gaming 3 ATX LGA1150 Motherboard
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory
Storage: Transcend SSD370 128GB 2.5" Solid State Drive
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive
Video Card: MSI Radeon R9 390 8GB Video Card
Case: Corsair 200R ATX Mid Tower Case
Operating System: Microsoft Windows 8.1 OEM (64-bit)
Monitor: Acer GN246HL 144Hz 24.0" Monitor
Keyboard: i-rocks KR-6401-BK Wired Slim Keyboard
Mouse: Corsair Raptor M40 Wired Optical Mouse

EDIT: well the PCPartPicker list did not work like it does on other sites. Sorry for the sloppy post.

 

[lehtv]

So I'm building my first PC and have 0 clue how much capacity a PSU can safely run at.

For short periods of time, high quality units can run safely at their full capacity. For instance, a system that actually consumes 400 watts at load can in theory be run perfectly safely with a top quality 400 watt unit - but it is not recommended as a long term solution.

As a rule of thumb, you should aim to use around 50% to 70% of the capacity at full load. This ensures:
- long term reliability (in particular, avoids wearing out capacitors too quickly)
- upgrade options - e.g. for a system that uses 50% of the power supply's capacity, you can easily swap in a more power hungry graphics card and still use under 70%
- comfortable load fan noise (power supplies ramp up their cooling fan's RPM significantly as they approach maximum wattage; the exact behavior of the fan curve varies)
- optimal efficiency

For systems where another graphics card can be added for a SLI or Crossfire configuration, you'll want a bit more leeway than usual.

Your R9 390 graphics card is quite power hungry, consuming up to 280W at load. Add 100W for the rest of the system and you're looking at 380W peak watts. I would recommend 550W as a minimum, preferably 620-650W.

Seasonic S12II 620W $60 AR @ newegg
EVGA 550W GS $66 AR @ newegg
EVGA 650W GS $76 AR @ newegg

CPU: Intel Core i5-4690K 3.5GHz Quad-Core Processor
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler
Motherboard: MSI Z97-Gaming 3 ATX LGA1150 Motherboard
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory
Storage: Transcend SSD370 128GB 2.5" Solid State Drive
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive
Video Card: MSI Radeon R9 390 8GB Video Card
Case: Corsair 200R ATX Mid Tower Case
Operating System: Microsoft Windows 8.1 OEM (64-bit)
Monitor: Acer GN246HL 144Hz 24.0" Monitor
Keyboard: i-rocks KR-6401-BK Wired Slim Keyboard
Mouse: Corsair Raptor M40 Wired Optical Mouse

Some free build advice:

4690K + Z97 only makes sense if you intend to overclock the CPU. If you don't, then you might as well buy i5-4590 and a B85 or H97 board - you'll only lose Crossfire/SLI compatibility and support for more than 1600mhz RAM. For a Z97 board I'd recommend 2133Mhz memory, it'll improve performance a few percent here and there, and doesn't cost much more.

i5-4590 $190 @ ncix or $200 @ newegg
Xeon E3-1231 V3 is another decent choice for a stock clocked gaming PC; like i7, it has hyperthreading which is currently of limited use in gaming but ensures a little better performance in heavily threaded games and applications.
Asrock H97 Anniversary $73 @ newegg - affordable, has everything you need
Gigabyte H97-D3H $88 @ newegg or amazon - as above, but with longer warranty and a better sound chip
Gigabyte Z97-HD3 $73 @ newegg - budget choice for running high speed RAM

240-256GB would be the optimal SSD size. Performance is a little better compared to 120GB drives, and you'll be able to install more than just 1-2 AAA games on it. Price per gigabyte is also better. Crucial BX100 250GB is a measly $27 more.

GTX 970 is worth considering from a performance/watt standpoint unless having 8GB of VRAM is a deal breaker - which it isn't on 1080p. R9 390 consumes so much more power that it'll cost easily $10-20 more electricity per year with active use.

 

[Yuriman]

I'd feel comfortable running that system with a 500w PSU, so long as you don't have a ton of accessories. Your video card will not frequently draw 280w.

 

[BonzaiDuck]

As Yuriman said. First thing worth the trouble: Go to the Extreme Outervision website to use the PSU calculator. I suspect that the results of the EOV calculator are slightly -- somewhat -- inflated.

For SSDs, worrying about their power consumption is like concern for adding a grain of rice to a pound of meat -- it won't matter much. Instead, there's the processor, the RAM, the graphics card. What are you going to expect from them at full load? Compare that with the EOV results.

I took a risk with my second (not sig) 2700K rig. I bought the first graphics card, and only after a month chose to buy the second. The PSU was a new Seasonic 650W I had available. I suppose I did the math and took the gamble. With the gfx cards OC'd and the processor OC'd, the APC UPS software was showing 590W at the wall under full load. 25W of that would be the monitor -- also powered by the APC UPS. One could then expect that the maximum power draw on the PSU would be ~ 0.9 x 565 = ~ 508W given the 90% efficiency rating.

I won't question Lehtv's assessment of the load wattage for a single R9 390 card. You can verify that number even in a set of reseller specs as you would find at Newegg. You could also find out the power consumption for the card as its maximum reasonable overclock.

But 280W, quoting Lehtv, should leave you some room for everything else.

If you plan on adding another gfx card or other components, you might want something rated at 750W or higher. In fact -- maybe 850. And -- get a good PSU. Some of the best are capable of sustaining as much as 100W in excess of the rated value before reaching a point where safety features cause them to shut down. So I might differ slightly from Lehtv on that angle, but I wouldn't exploit it. Give yourself some wiggle-room.

And also know -- cheap PSUs may be rated for some wattage, but they may actually fall short. Personally, for a guess that a PSU would sustain more than the rated wattage, I'd only trust Seasonic and a few others. That might include Seasonics that are rebadged and sold under a different brand-name, like XFX.