Signature 850 enough for 4870x2 build?

[Silverion77]

So i originally ordered the Antec 1200 and SG 850

ive made some changes though recently for the rest of my parts which may include a 4870x2 and H2O cooling

When i add in the parts on eXtreme calculator lite:
High end mobo
Q9550 (or Q6600 to cut $140)
OCed with about 1.4-1.5
4870 CF (i kno its not a x2 but they dont have one)
1 sata drive and DVDRW
a fan controller
and all the fans (for rads) and a pump
and 25-30% aging it says recommend about 850....which is exactly what i have...
Now im confused when they say recommended as thats what the pc needs or 850 with headroom

Will this pose a problem, i was considering refunding the 850 and grabbing the HX 1000 for the extra wattage.
What do u think?

Thx for any help

 

[dirtmountain]

I'd keep the 850w Signature.

 

[Zorg]

The calculator is the recommended PSU, with no consideration for 12V amps. The slop is unknown to me.

The The Truth About Graphics Power Requirements V2 - Atomic 3.0, which I had to find again because it looks like they redid the site (Thank God for stickies :lol shows the following:

HD4870 X2 -- 79W-87W-264W (264/12 = 22 amps)
HD4870 CF-- 128W-255W (255/12 = 21.25 amps)

Not that much difference as I far can see.

You are welcome to search out their source, it's fully documented. I have never questioned the numbers.

 

[Silverion77]

So the 850 will handle the 4870x2, pump and fans

I might not get the x2 now but rather the GX2 (i dont game at high res. so theyre basically the same performance and i save about $270) but the idea that future gpus will require more power, or more fans for more rads/pumps for a second loop idk, but u get my point

I mean i love the Sig. its a great psu, but if the 1000 will be more comfortable in my build, then ill swap

thx for the replies

 

[Zorg]

Understand, I'm not telling you what size to get or judging you for your selection. I was just filling in the missing data that you needed. Buy what makes you comfortable. I'm a big fan of having a PSU that is running at 60%. The whole idea of having a PSU running at 85-90% is ludicrous IMPO.

I know the 850 won't be running at 85-90%, but you get the idea.

 

[Silverion77]

yea i like about 60-70 percent. I just think its where 1) good efficiency is 2) doesnt load it that much and 3) leaves room for upgrades

but its gonna be a pain to upgrade (or exchange) for the HX1000 but ill do it. I saved $90 on the 850 w/ the case and then ill get a full refund so its not that bad w/ shipping and restocking.

 

[Zorg]

The 1000 does have bragging rights, but you'll have to add some load to justify it.