The GS and G2 are EVGA's best 80+ Gold PSUs. The G2 is probably slightly better due to its longer warranty (10 years vs 7 years, IIRC).

However, they're both fantastic PSUs. To put it in non-techy terms; you're talking about the difference between a Ferrari and a Lamborghini when the average desktop PSU (for example in a "normal" office machine) is more akin to a Vauxhall Corsa.

Indeed.
A very good price for Seasonic Gold.
Mind you, from most of the Ask questions and similar elsewhere, I can just see people buying this to run an i5 K and a sub-200W GPU for a total draw of under 350W. 850W is really only required for someone with 2-3 overclocked GPUs and an LGA2011 or AMD FX CPU overclocked like mad. And no, modern PSUs are not at their most efficient when running at 30-40% load.
Here's the JonnyGuru review
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=414

EDIT: What I mean to say is that the other deal for the 550W EVGA Supernova 550 GS Seasonic-made power supply is far more useful for (almost) everyone.

Well, there is some merit in that.
But don't forget that unless you game 100% or mine chances are the PSU will be far nearer 20% or less as even the most power hungry components idle well these days. AFAIR, aside from Titanium, none of the 80 Plus standards say anything about under 20% load (Titanium gives min 90% efficiency for 10% load). So with 1000W psu even with a power hungry rig, when it idles at under 100W (quite easily possible even for LGA2011 or AMD's FX) it will be running at an unknown efficiency. For non-Titanium rated supplies it's even worse as 20% of 1000W is 200W which might be reached even under 'some' loads.
So the sweet point is should probably be something so that the max load = 70% of the supplies rating. And my 'max' I don't mean a power-virus like FurMark on AMD cards which has mostly dependent on that AMD don't really throttle it like they should (and Nvidia do).

I hope you don't mind me looking at that statement as it intrigued me. The best info I can find is that this gold rated 850 watt PSU will be running at 90% efficiency at 50% of full load i.e. a load of 425 watts. Which compares very well with say a 550 watt gold rated PSU which will run on 100% full load at 87% efficiency

The actual efficiency figures for a gold rated PSU are 87% at 20% load, 90% at 50% load and 87% at 100% load. So 50% of full rated load is the sweet spot as far as efficiency is concerned but it is only a 3% variation in efficiency over the loading range anyway. The biggest savings in efficiency come from selecting a gold PSU, an 80 plus PSU for example is only 80% efficient at any loading.

Link to figures
http://www.tomshardware.co.uk/power-supply-protection-calculate-consumption,review-32356-2.html

Free delivery if you are a member of Hexus forums with 20+ posts.

You had me at EVGA..

I ordered one for pick up for 4.79 £ from UPS acces point ☺

Think they want £9.58 for delivery tho?

perfect timing for my new PC build.

thanks op. heat added.

People fail to factor. PSUs degrade over time. I put a 1200w evga platinum in my I7 4790K with a zotac 980ti amp. Im able to put it into eco mode and still have juice to spare. Some psus can last you over a decade if you plan ahead. Its one of the few components that will outlast the current system.

No matter...

Can anyone advise please? I'm currently looking for parts for a new build. I currently have a gtx 970 and was thinking maybe further down the line grabbing another and use them in sli.

Would this be a good power supply for that purpose. I was looking at the g2 version but is there a big difference in performance? Don't know much about them to be honest.

Any advise greatly appreciated.

The review of the 550W says it has 'only' 6 SATA but it also has 3 Molex and Molex<>SATA adapters are cheap and safe.
Of course, this did score better than the 550W with 9.6 vs 8.9 and the reviewer praised the voltage regulation unlike the 550W, plus it actually passed Platinum during testing. Mind you, £90 vs £60 is 50% more...

http://www.coolermaster.com/power-supply-calculator/ I just calculated how much power my PC takes and it says I need 457W so this is overkill but if I would run SLI it is just right however I need all those extra connection for my hard drives because I have 8 of them :wink:

So much power, so little use these days with cards more power efficient and less thirsty.

That's a really decent power supply, and a good price for how things are at the moment.

Great price and great kit too.

Check dimensions before ordering to ensure it fits however!