Sign in with
Sign up | Sign in
Your question
Solved

Help about CrossFireX and PSU

Last response: in Graphics & Displays
Share
February 24, 2014 1:56:36 PM

My PC specification:

Processor: Intel Core i7-3770K
CPU Cooler: Intel Stock (Will upgrade to H100i soon)
GPU: Asus Radeon R9 270X
Motherboard: MSI Z77A-GD65
Ram memory: Kingston HyperX Beast 2x4GB 2400Mhz
PSU: Chieftec modular A80 750W
Case: Cooler Master 932 HAF Advanced Tower
Reader/Writer: Asus DVD/RW
HDD:Seagate Barracuda 2TB 7200rp

This is picture of my PSU:
http://www.overclockers.ua/power/chieftec-ctg-750c/07-b...

Question:
Can I do 3x CrossFireX with this PSU with 3x Asus R9 270X?

Thanks!

More about : crossfirex psu

February 24, 2014 2:46:55 PM

The recommended wattage for 2x Radeon 270X's in Crossfire is 700w, so I'd imagine 3x 270X's would have trouble with 750w.

I run 2x 270X's on a 700w Thermaltake PSU and they run great.

I also noticed that your motherboard's PCIe configuration would be x8 and x8 with two video cards, but x8, x4 and x4 with three video cards.
http://www.anandtech.com/show/6902/msi-z77agd65-gaming-review (for the Gaming variant, but still the same PCIe configuration)

Something to think about, although an x4 PCIe Gen3 slot is the equivalent of an x8 PCIe Gen2 slot which many video cards can't fully saturate so the impact would be minimal.

I'd suggest just going with two 270X's or upgrading your PSU if you really want to run three.
m
0
l
February 24, 2014 3:18:40 PM

Ok, I will get 2x for sure, no need 3x, too much, just asked.

And you mean, my motherboard is bad?
m
0
l
Related resources

Best solution

February 24, 2014 3:26:55 PM

serbiandevil said:
Ok, I will get 2x for sure, no need 3x, too much, just asked.

And you mean, my motherboard is bad?


Oh not at all, your motherboard is much better than mine and it handles dual 270X's like a champ.

You're all good!
Share
February 24, 2014 4:47:39 PM

serbiandevil said:
Ok but if you can see on picture "http://www.overclockers.ua/power/chieftec-ctg-750c/07-c..." VGA-1 and VGA-2 are busy on my PSU for my one Asus R9 270X, I see no where to put power cable for my new GPU wich I will buy soon?

Your 270X should've come with a couple molex to PCIe 6 pin adapters, as your new one should. That'll give you the connections you need.
m
0
l
February 25, 2014 12:42:50 AM

OK, what I'm now using:

-On VGA1 port "http://www.overclockers.ua/power/chieftec-ctg-750c/07-c..." I'm using cable "http://www.pcpower.com/images/products/b/PCIE-6-8_3853...."
-On VGA2 port "http://www.pcpower.com/images/products/b/PCIE-6-8_3853...." I'm using cable "http://www.pcpower.com/images/products/b/PCIE-6-8_3853...."

From where I got them? From PSU, should I continue do this or replace with molex and should I use 2x cables for my one GPU? Teach me, I'm noobish. :( 
m
0
l
February 25, 2014 11:50:04 AM

Wait! I just looked at the picture of your PSU and you're using VGA 1 & 2 with 6 pin adapters to your 270X correct? You're not using any of the four PWR connections? Those are already 6 pin so you can get yourself a couple 6 pin male-to-male cables (some should've come with your PSU) and use PWR 1 & 2 just fine :) 

Refer to this diagram I made, and excuse the poor quality:

m
0
l
!