Needing some advice (i7 3770k w/ASUS Sabertooth z77

[diggeh]

Hello people, i need some help on upgrading my current Pc, heres my specs currently.
Corsair 500w PSU
Amd Phenom IIX4 965 @4.1GHZ
ASUS Radeon 6850 1gb
Asus M4A78LT-M motherboard
16gb DDR3 Ram 18(00) MHz.

I am looking to upgrade to an i7 system soon, i have decided on an ASUS sabertooth z77 and an I7 3770k.
I'm only gonna change the motherboard and processor and transfer over my PSU, GPU and RAM.
I am also looking to buy another ASUS 6850 as the Mobo can hold 4 GPU's, my question is, Can i have this system with my current 500w PSU?
-All answers apreciated.
Thankyou very much.
Diggeh.
Also what GPU would be an equivalent to 2x 6850's?

 

[tsnor]

Google TDP plus the name for each of your major parts. For example google TDP and HD6850 you'll find the HD6850 uses "TDP is 127W" 127W. Google i7-3770K with TDP and you get 95W. Add in 50 for MB, disk, mem, etc and you get around 250-300W for system with one video card and 375-425 for system with two video cards. It fits.

Two big gottchas.

1. Overclocking your video uses more power. For some video card quite a lot more. For hd6850 maybe 20w to 30w more per card unless you go crazy. (ref: http://www.anandtech.com/show/4002/amd-radeon-hd-6850-overclocking-roundup-asus-xfx-msi/8) Note leakage power will go way up if you can't keep the card cool. So add another 50W for OC video. You are past what your PSU can deliver. You are paying for an unlocked processor, so you will probably be OC it too. Forget the 500W PSU working if you overclock.

2. The PSU rating includes all the voltages, you are only really using +12v. A corsair builder series 500w PSU has +12V@38A = roughly 450W of 12V (is that the PSU you have?). Some PSU makers invent their specs, sometimes they are not real. Corsair has a good rep, however the 500W rating is at a temp. If your PSU gets hot (like under load next to hot video cards) then its rating can go down. Net you are close with the 500W but I personally would get more power before going to dual video cards. No problem with a single card. No overclock should work with dual cards, but you are buying the wrong processor if you don't intent to OC (the K version costs more, as does the OC friendly MB).

p.s. most gamers would go for an i5 instead of the i7 and save the extra money for other components. The lack of hyper threading in the i5 doesn't seem to hurt gaming.

p.p.s read about microstutter. And crossfired HD6850s would play crysis: http://www.techpowerup.com/reviews/ATI/Radeon_HD_6850_CrossFire/8.html