870a-G54 w/ 2 6990s?

[circumventor]

I've posted a similar thread asking about running 2 gpus on a 650w PSU but it was brought to my attention that my motherboard can only support one. He claimed that one of the PCI-e 16x slots was only wired for 8x but I did some testing and my current 5770 runs fine in both slots. My parents want to celebrate my good grades so they offered to buy me a 6990 for my birthday and another one for christmas. Seems like a generous offer but I get paid on Friday and I need to know if my current motherboard will support two of those massive cards. I already plan on getting a new power supply and I am upgrading to the lates 8-core processor. If anyone knows anything about my board (870a-g54) supporting a quad-gpu setup please let me know.

 

[swifty_morgan]

you don't need 2 6990's.

 

[gmcizzle]

Your mobo only support 16x/4x, meaning the first card will be running at full speed but the second will be running slower. 4x mode will result in 8-10% performance decrease and may not be as smooth as 16x. What are the rest of your specs? No sense in spending $750 for a 6990 unless your comp can handle it.

 

[circumventor]

I thought that I would get the best possible system. I can get a new motherboard but I just didn't know if I really HAD to if you know what im saying. My current specs are:

Phenom II x4 955
6GB 1333mhz RAM
650w PSU
Motherboard listed above
3 hard drives
HD 5770

I was planning to upgrade to:
AMD 8150 8-core
Asus Formula Extreme Mobo (that red one)
12GB 1333mhz RAM
Dual 6990s
Also adding 2 more monitors which ive already ordered.
1200w PSU w/ Modular Cabling
some other goodies.

I figured I would need some crazy graphics power to get decent frame rate in BF3 on max settings.

 

[gmcizzle]

Here's what I recommend:

Buy the 1200w PSU and 2 GTX 580s now. When Sandy Bridge E comes out, then upgrade to one of their 6-cores, mobo, RAM, etc. and if you need to, buy another GTX 580 for tri-sli 580's (which smoke 6990s in crossfire). Some preliminary benchmarks show the bulldozers as comparable with the i5-2500k, but the Sandy Bridge E's when they come out will be the top dog.

 

[circumventor]

I dislike intel. AMD's new 8-core procs come out and are only $300 and are comparable to the $1,000 990X from Intel. Im just going to stick with AMD and Radeon GPUs. AMD cards are better anyway.

 

[gmcizzle]

The entry level 6 core CPU in Sandy Bridge E will be around $500, and it will be a beast of a setup with X79's quad-channel memory. Bulldozer will be released in a day so you can see the performance of them yourself, but based on some early benchmarks it can only compare with the i7-2600k.