r9 290 Crossfire + HD 7970 All in One Case

[wwjones14]

Hello there, so I am looking to purchase two r9 290s to put into crossfire. I currently have an HD 7970. The following are the PC components I would have for this setup.


GIGABYTE GA-990FXA-UD3 AM3+ AMD 990FX SATA 6Gb/s USB 3.0 ATX AMD Motherboard

(link to motherboard) http/www.newegg.com/Product/Product.aspx?Item=N82E16813128514

x2 PowerColor AXR9 290 4GBD5-MDH/OC Radeon R9 290 4GB 512-bit GDDR5 PCI Express 3.0 CrossFireX Support Video Card

SAPPHIRE 100351SR Radeon HD 7970 3GB 384-bit GDDR5 PCI Express 3.0 x16 HDCP Ready CrossFireX Support Video Card

EVGA SuperNOVA 1000 P2 80 PLUS PLATINUM Certified 1000W Active PFC ATX12V v2.31/EPS 12V v2.91 SLI Ready CrossFire Ready ECO

ZALMAN CNPS9700 LED 110mm 2 Ball CPU Cooler

AMD FX-8350 Vishera 4.0GHz (4.2GHz Turbo) Socket AM3+ 125W Eight-Core Desktop Processor FD8350FRHKBOX

G.SKILL Ares Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1866 (PC3 14900) Desktop Memory Model F3-1866C9D-8GAB

TP-LINK TL-WDN4800 Dual Band Wireless N900 PCI Express Adapter, 2.4GHz 450Mbps/5GHz 450Mbps, IEEE 802.1a/b/g/n

CM Storm Trooper - Gaming Full Tower Computer Case with Handle and External 2.5" Drive Dock


Now the main reason I want to keep the HD 7970 in my PC is for altcoin mining purposes. (Not bitcoins but coins based on scrypt). My case is a full size tower so room shouldn't be an issue. The thing is because my motherboard only has two x16 PCIEs I would have to put my HD 7970 in a x4 PCIE. The r9 290s would be in the two x16 slots. This would hypothetically work correct? I am fairly sure that a x4 slot means that the 7970 may not be used to its fullest potential but I've heard that for mining altcoins a x4 PCIE slot is no different from a x16 PCIE slot. When I would install the drivers would I have to do so in a certain order? Because of the fact that there would be 3 graphics cards in one case and I have heard that the r9 290s can get quite hot under a large load would aftermarket coolers be recommended/necessary? I know that my 7970 while mining or extreme gaming never got above like a 70 temp even after overclocking. However, ideally I would like to unlock the r9 290s to r9 290xs as done here

http/www.overclock.net/t/1443242/the-r9-290-290x-unlock-thread

I would love to hear an expert's opinion on whether this setup would work or not. And when I'm not mining I do extensive gaming often on my PC on a 2560 x 1440 27 inch screen just in case you would like to know. Would the HD 7970 actually do anything to help out while I gamed? Thank you for your time, answers to any of these questions would be much appreciated.

 

[iceclock]

Why not just order a second 7970 that be cheaper

 

[wwjones14]

Why not just order a second 7970 that be cheaper

I don't want to do that because I am a gamer as well, and if I am getting new graphics cards I want graphics cards that are a good investment in both gaming and mining. A 7970 crossfire setup just doesn't compare to a r9 290 crossfire setup gaming wise. And the r9 290s are better at mining as well. In my opinion the r9 290s are a fantastic deal and I have the money to spend on them.

 

[iceclock]

well atm the 290s are having issues. heat and trottling issues i wouldnt invest in one or 2 until they release new coolers for them.

as taking apart the cooler and replacing it voids ur warranty.

if u want something good atm get 2x280xs

 

[coozie7]

You own your own nuclear power station? 😉
Unless someone else can state positively one way or another all I will suggest on the mining issue is to try it and see, if it doesn't work, just uninstall the HD7970 and drivers.
You definitely, positively cannot crossfire different chips though, so using the R9s and 7970 together for gaming is definitely not going to work.
Running a pair of R9 290s in CF is going to be so noisy I'm not sure you'd want to unless you go for a water cooling loop or you're going to wait until cards with better coolers arrive (which will create their own problems, namely stopping the case from melting from the inside out).
Toms recently did an article on equipping an R9 290 with a Acrtic accelero cooler: http/www.tomshardware.co.uk/r9-290-accelero-xtreme-290,review-32828.html Works extremely well but obviously voids the warranty.
If you live in the UK I can offer an alternative.