4890 crossfire help

[adam123222]

Hi, Here are my specs...

Graphics card - HD ATI radeon 4890 OC XXX 1GB- will overclock for you on request via email after purchase.

Motherboard - Asus M4A78T-E AMD 790GX (Socket AM3) PCI-Express DDR3 Motherboard

Power Supply - OCZ 750W SLI PSU

Processor - AMD Phenom II X4 Quad Core 955 Black Edition 3.20GHz (Socket AM3)

Cooling for CPU - Zalman CNPS9700-LED CPU Cooler (Socket 754/939/940/AM2/LGA775)

HDD/Hard Drive - Hitachi Deskstar P7K500 500GB SATA-II 16MB Cache - OEM

DVD RW drive - Sony Optiarc AD-7240S 24x DVD±RW SATA ReWriter

RAM - Crucial Ballistix 6GB (3x2GB) DDR3 PC3-10600C7 1333MHz Triple Channel

Am thinking about adding another radeon 4890 for CF. Can my current PSU handel another 4890? and my motherboard has two pcie slots however it says that if i have crossfire each pci-e slot goes from x16 to x8? what will this mean in fps?

And will having 2 4890s be twice as powerful as a single 4890?

Thank you

 

[Niklas_13]

Your PSU will be fine to xfire 2 4890s

Your bandwith will be cut from 16X to 8x8x a mobo with 16x16x vs 8x8x will be about 4 to 7 % differnt in FPS not much to worry about maybe 5 FPS

Having 2 GPU xfired will not give you twice as many FPS. Xfire will scale differnt depending on the game, say you get 40 FPS with one GPU xfire you might get 60 FPS

A review of xfired HD 4890s http://www.techpowerup.com/reviews/ATI/HD_4890_CrossFire/1.html

 

[adam123222]

ok thanks and how will this xfire setup compare to a GTX295? taking into account the 7% you mentioned. Will the performance be about the same? And what kind of head room will there be when i have my 2 4890s?... would i be able to say add 2x 2tb hard drives in the future?

Thanks for your reply

 

[Niklas_13]

Read the link i posted it shows the GTX 295 vs the HD 5890s xfired

You should have no problem with xfired 4890s and a few HDD with the PSU