Whats a good 850w power supply for my build?

First of all 850W is waaaay too much for your buid unless you're gonna add an extra GTX 780 with SLI.
A 650W would be just fine with room for OC in the future, check this possibilities:

Mid range price, mid range brand 80+ Gold = will do the job like a pro:
http://pcpartpicker.com/part/evga-power-supply-120pg0650gr

Mid-high range price, High end brand 80+ Gold = Great for the money:
http://pcpartpicker.com/part/evga-power-supply-120pg0650gr

Just the best, a bit expensive dho:
http://pcpartpicker.com/part/seasonic-power-supply-ss660xp2


In any case youll be just fine with each one of them so Enjoy!

Having more room is always a good idea, for future upgrades, also the PSU would be working at midle load wich is the point where it gets better efficiency and lower-noise and ripple levels, so a 750W PSU for that rig would be just fine.
Remember to pic good branded certified PSUs only, something like Seasonic, XFX, Corsair, Antec.

Try to choose from Tier-1

Tier-1 provides the best quality power, great for overclocking, super high-end systems, and bragging rights. The best of the best. Very good longevity.

Tier 1 Brands - The Most Powerful And Stable Components On The Market.

Antec Signature
Antec High Current Pro -1200w
Antec HCP Platinum 1kW
Cooler Master V series 700, 850, 1kW
Corsair AX
Enermax Galaxy
Enermax Revolution
EVGA SuperNova G2 1000W and 1300W
Kingwin Lazer Platinum
PCP&C TurboCool
PCP&C Silencer Greater than 610 watt
Sapphire Pure
Seasonic X-Series
Seasonic S12D/M12D
Silverstone ZF (Etasis 85/75/56)
Seventeam ST Greater than 600w (SSI, V2.91)
Silverstone OP/DA Greater than 700 watt
Silverstone ZM
Ultra X3 Greater than 1000 watt
XFX Black Edition
XFX XXX Edition
Zippy/Emacs SSL
Zippy/Emacs GSM
Zippy/Emacs PSL
Zippy/Emacs HG2
Zippy/Emacs HP2

GeForce GTX 780 - requires 42 Ampere on +12V rail and a 600W PSU minimum

And not all PSU can handle HASWELL CPU, there are incompatibility issues.

So you can go with this one, sufficient for your need, unless you want to OC or SLI.

PCPartPicker part list / Price breakdown by merchant / Benchmarks

Power Supply: Corsair Enthusiast 650W 80+ Bronze Certified ATX Power Supply ($99.98 @ TigerDirect)
Total: $99.98
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-12-15 09:19 EST-0500)

Made by SEASONIC , and probably the best 850w. on the market at a great price.

PCPartPicker part list / Price breakdown by merchant / Benchmarks

Power Supply: Cooler Master V850 850W 80+ Gold Certified Fully-Modular ATX Power Supply ($159.99 @ Microcenter)
Total: $159.99
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-12-15 09:39 EST-0500)

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=350

Scoring

Performance (40% of the final score) - voltage stability? Excellent. Ripple suppression? Excellent. Pass for Gold efficiency both times. Units like this make scoring easy. 10.

Functionality (20% of the final score) - this unit is more or less identical to big brother in this department, so it should come as no shock that I'm going to score it much the same way. I'd still like to see a SATA chain with some more length, and a few extra goodies in the box. I'll remove a half point for each of those issues again. But, there's more. I feel an extra CPU cable isn't a bad thing on an 850W unit. The modular board on the unit has the extra connector, so why not throw that in? Especially when the Seasonic G-650, a far smaller unit, came with one. Another half point off for that. But there I will stop, because this unit by far does a lot of things right more than wrong. It's fantastic. It just could have been even better, I think, in this category. 8.5.

Value (20% of the final score) - this unit is currently going for $139.99 at Newegg. That's insane for a unit of this caliber! Know what the Seasonic equivalent is going for? Thirty bucks more money, and THAT price is still not a bad value. Folks, for the second week in a row, we've seen a unit that totally dominates its price bracket. Only the Corsair HX850 and XFX Pro Series Black 850W gives this thing any competition, and they're still ten dollars more money. Can't do anything but 10 here again.

Build Quality (20% of the final score) - I found no issues whatsoever to complain about inside this unit, except for maybe the lack of any thermal grease on the 12V output heatsink where the two parts bolt together. Since this does not appear to be an issue for forty or even fifty degree operation at full power, this is a non issue. I smell another 10.

Performance


10

Functionality


8.5

Value


10

Build Quality


10
Total Score

9.7

tier1 is just a list with the best PSUs on the market , providing the best quality power, great for overclocking, super high-end systems, and bragging rights. The best of the best. Very good longevity.
here is the full Eggxpert Tiered Power Supply List :
Tier Breakdown:

Tier 1 provides the best quality power, great for overclocking, super high-end systems, and bragging rights. The best of the best. Very good longevity.
Tier 2 offers very good quality power output, and great reliability. Highly recommended for use in new systems.
Tier 2b contains units that almost made Tier 2, but may not have quite as good quality output(still very good), or may not last as long. Recommended for systems not expected to run 24/7 for several years.
Tier 3 power supplies fully meet all ATX requirements for power output quality, but don't have as good of power output quality as above tiers. No reason to replace one if you have one, and they're still good choices for most systems.
Tier 4 units may have some problems, such as being unable to deliver rated power at higher temperatures, or being slightly out of ATX spec on power output quality. Not recommended to buy except in situations where you will not be stressing it, or expecting it to last for more than a few years. If you have one, you can probably keep using it unless you're experiencing problems.
Tier 5 power supplies are NOT RECOMMENDED. If you have one, you should strongly consider replacing it ASAP. These can damage your computer, and often cannot put out the power that they're rated for. If a brand name is listed here, then all models from that brand name are considered to be Tier 5, except for those specific models listed above.


-----x-----x-----x-----x-----x-----x-----x-----

Tier 1 Brands - The Most Powerful And Stable Components On The Market.

Antec Signature
Antec High Current Pro -1200w
Antec HCP Platinum 1kW
Cooler Master V series 700, 850, 1kW
Corsair AX
Enermax Galaxy
Enermax Revolution
EVGA SuperNova G2 1000W and 1300W
Kingwin Lazer Platinum
PCP&C TurboCool
PCP&C Silencer Greater than 610 watt
Sapphire Pure
Seasonic X-Series
Seasonic S12D/M12D
Silverstone ZF (Etasis 85/75/56)
Seventeam ST Greater than 600w (SSI, V2.91)
Silverstone OP/DA Greater than 700 watt
Silverstone ZM
Ultra X3 Greater than 1000 watt
XFX Black Edition
XFX XXX Edition
Zippy/Emacs SSL
Zippy/Emacs GSM
Zippy/Emacs PSL
Zippy/Emacs HG2
Zippy/Emacs HP2


Tier 2 Brands - Top Quality components With Top Notch Stability - For Those With Price/Availability Issues With Tier 1

Antec Neo HE
Antec High Current Gamer Series
Antec EarthWatts greater than 700 watt
Antec TruePower Trio
Antec TruePower Quattro
Antec TruePower New -- 750w
Akasa PowerGreen 80+
CoolMax CTG-750 watt/850 watt/1000 watt
Cooler Master Ultimate/UCP
Cooltek CT
Corsair GS600 / GS800
Corsair HX
Corsair RM 550
Corsair TX
Corsair VX
Cougar SX700 and GX700
Enermax Liberty
Enermax Infiniti
Enermax MaxRevo 1350
Enermax MODU82+
Enermax Platimax (600, 750, 850, 1.2K)
Enermax PRO82+
Enermax PRO87+ (500w + 700w)
Enermax Triathlor (550, 650, 700)
Enhance ENP-GH
Fortron (FSP) GLN
Hale82-m 650-750w
iStarUSA PD2
iStarUSA PD3
LEPA G500
OCZ EliteXStream
OCZ Fatal1ty
OCZ GameXStream less than 1000 watt (only if manufactured in December 2007 or later)
OCZ StealthXStream 400 watt
OCZ StealthXStream 2 greater than 700 watt
OCZ Modstream (only if manufactured in December 2007 or later)
OCZ EvoStream
OCZ ProXStream
OCZ Z(t)(s) Series Less than 1000W
OCZ ZX 850w
PC P&C Silencer less than 610 watt
PC P&C Silencer MkII
Rosewill Capstone (450, 750)
Rosewill Hive (550, 650)
Seasonic G series
Seasonic S12
Seasonic M12
Seasonic Energy Plus
Sentey Golden Steel Power 850w
SevenTeam ST less than 600 watt
Silverstone OP/DA 700 watt or less
Supermicro/AbleCom
Thermaltake Toughpower greater than 600 watt
Thortech Thunderbolt Plus 800w
Topower Powerbird 900w
Xclio StablePower
XFX Core Edition
Xigmatek MC
Xigmatek HC
Ultra X3
Ultra X-Pro
Zalman ZM less than 1000 watt


Tier 2b - Tier 2 units which have either lower longevity or slightly lower quality output. Still well within spec, and are good units.

ABS-Tagan ITZ/BZ less than 1000 watt
Antec VP (350, 450)
BFG 800 watt
Cooler Master GX 80 Plus 450W
Cooler Master Real Power Pro >greater than 800 watt
Cougar S700
Enermax NAXN-82 550w - 750w
Hiper Type-M >greater than 650 watt
Hiper Type-R >greater than 650 watt
Huntkey Jumper
Kingwin Lazer Gold
LEPA B650, B850
Mushkin Enhanced
NZXT HALE
OCZ PowerStream
OCZ StealthXStream <less than 700 watt (only if manufactured in December 2007 or later)
Rosewill Green 630w
Silverstone EF
Tagan U95
Tagan U25
Tagan U15
Tagan U22
Topower Powerbird 1100w
Xclio GreatPower


Tier 3 Brands - Power supplies fully able to meet ATX specs, although closer to the edges of the limits than higher tier units. Still solid units.

Acbel Polycom
Akasa PaxPower
Akasa PowerPlus (>greater than 500 watt Models)
AMS Mercury
Antec Earthwatts >greater than 700 watt
Antec Basiq
Antec Phantom
Antec TruePower III
Antec TruePower II
Antec TrueControl II
Antec NeoPower 480 watt (Old Model)
Athena Power Space Shuttle Series
Be Quiet Dark Power Pro
BFG ES
BFG LS
Channel Well
Cooler Master Real Power Pro <less than 800 watt
Cooler Master iGreen
Cooler Master Silent (and gold) Pro
Corsair CX Series
Corsair RM750, RM850
Enermax Maximum Plus
Enermax Noistaker II
Enermax Noisetaker
Enermax Whisper II
Enermax CoolerGiant
Enhance ENS-G
Epower Xscale
EVGA SuperNova NEX B 500
EVGA SuperNova NEX G 750
EVGA SuperNova NEX 1500 Classified
Fortron (FSP) GLC
Fortron (FSP) THN
Fortron AX
Fortron HLN
Fortron PFN/PN/PA
Fractal Design Integra R2 750 W
Kingwin Lazer
Kingwin Mach 1 (the negative 12v rail may go slightly outside of spec in some loading conditions)
LEPA G900
NorthQ
OCZ ModXStream (rated for 40° C)
OCZ Z Series 1000W
Rosewill RP 2 (temperature sensitive)
Rosewill Xtreme/RX
Seasonic Super Versatile
Sigma SP
Silverstone F
Sparkle FSP
Spire Rocketeer V/VI
Sunbeam Nuuo
Thermaltake Litepower
Thermaltake Purepower RX
Thermaltake Toughpower <less than 600 watt
Topower 1000w Gold
XG Magnum
X-Spice Kira
Zalman ZM 1000 watt




Tier 4 - Not Recommend for stressful situations. May not be able to put out full rated power above room temperature, and may slightly fail to meet ATX specs.

Aerocool
Asus Atlas
BFG 1000 watt
Cooler Master eXtreme (only use 75% of labeled wattage)
Cooler Master GX (except 450w)
E-Power
Futurepower
Hale82n 650w
Hiper Type-M
HIPRO
Masscool
MGE XG
Mushkin HP
NorthQ 4775-500S/BU
OCZ Modstream (if manufactured before December 2007)
OCZ GameXStream <1000 watt (if manufactured before December 2007)
OCZ StealthXStream (if manufactured before December 2007)
OCZ GameXStream 1010 watt (essentially a 850watt power supply)
Scythe Kamariki
Sigma Shark
Sintek
TTGI/Superflower
Ultra Xfinity
Ultra X2 <less than 700 watt
Ultra XVS
Xion Real Power PowerReal


Tier 5 - Other than the units listed above for any of these brands, NOT RECOMMENDED. Replace ASAP if you have one.

A-TOP Technology
Apevia
APEX (SUPERCASE/ALLIED)
Aspire(Turbo Case)
ATADC
Athena Power
ATRIX
Broadway Com Corp
Coolmax
Deer
Diablotek
Dynapower USA
Dynex
EagleTech
FOXCONN
FSP Everest
HEC Orion
Hiper Type-R
Huntkey
I-Star Computer Co. Ltd
In Win
JPAC COMPUTER
Just PC
Kingwin Inc.
Linkworld Electronics
Logisys Computer
MGE
MSI
NMEDIAPC
Norwood Micro/ CompUSA
NorthQ
NZXT
Okia
Powmax
Q-Tec
Raidmax
Rocketfish
Rosewill
SFC
Shuttle
Skyhawk
Spire Coolers
Star Micro
STARTECH
Thermaltake Purepower NP
Thermaltake Purepower RU
Thermaltake TR2 (and TR2-RX)
TOPOWER TOP
Ultra X-Connect
Ultra X2 >greater than 700 watt
Ultra LSP
Wintech
XION
YoungYear
Zebronics

Get the 850w I linked above, it's the best in it's class and the price is also.

It's made by SEASONIC not Coolermaster.

Yes it is , but what you purchase is your choice.

I only offer advice.


Tier 1 Brands - The Most Powerful And Stable Components On The Market.

Antec Signature
Antec High Current Pro -1200w
Antec HCP Platinum 1kW
Cooler Master V series 700, 850, 1kW
Corsair AX
Enermax Galaxy
Enermax Revolution
EVGA SuperNova G2 1000W and 1300W
Kingwin Lazer Platinum
PCP&C TurboCool
PCP&C Silencer Greater than 610 watt
Sapphire Pure
Seasonic X-Series
Seasonic S12D/M12D
Silverstone ZF (Etasis 85/75/56)
Seventeam ST Greater than 600w (SSI, V2.91)
Silverstone OP/DA Greater than 700 watt
Silverstone ZM
Ultra X3 Greater than 1000 watt
XFX Black Edition
XFX XXX Edition
Zippy/Emacs SSL
Zippy/Emacs GSM
Zippy/Emacs PSL
Zippy/Emacs HG2
Zippy/Emacs HP2

http://www.corsair.com/us/blog/haswell-compatibility-with-corsair-power-supplies/

The Cooler Master V850 :



High price/performance ratio
Delivered full power at 45°C
Tight voltage regulation
Excellent ripple suppression
Efficient
Performance in Advanced Transient Response tests
Fully modular design
Quiet operation
Great build quality
High quality (FDB) fan
Japanese caps
5 year warranty
Flat and stealth modular cables

http://www.techpowerup.com/reviews/CoolerMaster/V850/

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=350


Take care and thanks for posting in the forum.

Yes you can do some OC with that PSU. And take a look at here for reviews, specs, and warranty.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139005

Any calculators showing you need 750 for a sys with 1 780 are building in way more headroom than you need.
A good quality 550 will run that system. There's no problem using a 750 except to your wallet in upfront cost.

If you are convinced you want an 850, the CM V850 blackbird linked is an excellent unit. The 3 V series CM PSU's
all made by Seasonic are ex quality.

I AGREE 100% FROM MY PERSONAL EXPIRIENCE THE COOLERMASTER V850 IS INCREDIBLE AND YES IT IS MANUFACTURED BY SEASONIC.