Dual HD 7970's in Mavericks 10.9.4

[POSTpro]

I am starting this thread to provide some information, and ask some questions, about dual HD 7970's. First off, I scoured the internet for any information about these two GPUs being used together in a hackintosh. I found precious little information. So here is what I've learned.

1) I had to upgrade my HX650 PSU to a HX850 PSU that I picked up on ebay for $65+$13 shipping.
2) The cards were detected OOB (2x Gigabyte 7970OC 3GB Rev 2.1) - got 2nd card off ebay for $144.50
3) I do have the crossfire cable connected
NOTE: I'm using MacPro 5,1 system

I haven't had much time for testing so I really don't know how they will perform on a day to day bases. I use FCPX almost daily so this should be interesting to see how it handles the two cards. I did run Luxmark and Heaven and am posting those screen shots. I will try to update this thread as I get more experience.

On the PC side of things I did a quick BF4 test. On one monitor at 1920x1080 ULTRA settings I did not drop below 90fps and was hovering around 110-120fps.

I have 3 Dell S2330mx 23" monitors connected to one of the cards: 1 mini Display, 1 HDMI and 1 DVI-d. Each are at 1920x1080 and they all work great!

One question I do have is: Why does one of my cards show the pcie lane to be 8x and the other 4x? I do have a Blackmagic Decklink Mini Monitor on the other pcie lane. Would this cause the other two lanes to show up as 8x and 4x? Is this even a problem that I should worry about?

Thank you in advance and please add your experience to this thread if you have dual HD 7970s.

 

[binh828]

POSTPro,

I cannot answer your questions but I do have a couple of questions for you that could help me.

I'm trying to run 4 monitors using 2 different GPUs (GTX 650 and GT 610) but so far unsuccessful.

1) Just curious, if you plug 1 of your 3 monitors into the other GPU -- would it work? Mine doesn't, the monitors go to power save mode.

2) In your Graphics system, I cannot get my Intel HD4000 to show up like yours -- how did you do that? I have the ASUS P8Z77-V PRO

I do notice that my GPUs are x16 and x1 / 8x and 8x -- depending on which PCIe slots I install them on.

my thread: http://www.tonymacx86.com/graphics/140797-multiple-gpus-4-monitors-mavericks-help.html

Thanks!

 

[POSTpro]

binh828: I will post my thoughts to your questions on your thread. I will also do some experimenting with monitor connections and post on this thread as well.

 

[POSTpro]

#1) I've had a little more time to dig around and did find the answer to my own question regarding the PCIe lanes. Here is what the Gigabyte website clearly states:

* The PCIEX4 slot is available only when an Intel 22nm (Ivy Bridge) CPU is installed.
* The PCIEX4 slot shares bandwidth with the PCIEX8 and PCIEX16 slots. When the PCIEX4 slot is populated, the PCIEX16 slot will operate at up to x8 mode and the PCIEX8 will operate at up to x4 mode.
(The PCIEX16, PCIEX8 and PCIEX4 slots conform to PCI Express 3.0 standard.)
* PCIE Gen.3 is dependent on CPU and expansion card compatibility.

That does lead me to another question though. Since I do have the 3rd PCIe lane occupied with the Blackmagic Decklink Mini Monitor and it is "sharing bandwidth with the other two lanes, will this effect the dual HD 7970 performance? Since they are running at 8x and 4x? Example: If I'm in FCPX and am rendering the timeline and monitoring to my HDTV via the Decklink Mini Monitor, will that effect the render process? And if so, how much? Would I even notice any benefit loss?

#2) I did some hot swapping of the HDMI monitor cables to see what would happen. I first moved one HDMI cable from top HD7970 to bottom HD7970 and had no issues. System information showed the connection information after a "refresh information". Then I hot swapped the HDMI to HDMI->DVI-d from the top HD7970 to the MB HDMI port. This caused the screen to fragment and required a restart to fix. Once rebooted System Information showed each GPU as being connected to one monitor each and they all displayed correctly. Hopefully that makes sense.

#3) Probably the most critical question I have is this: Since adding a new PSU and 2nd GPU my hackintosh does not power off anymore. I had this problem a few OSx updates ago but it went away on it's own (hmmm) but the problem has now spread to the Windows 8.1 side of things. When I select shut down in OSx/W8.1 It acts like it is going to shut down, screens power off, but computer just keeps going. What can I do to solve this?

 

[thewisevaloo]

Hey, I'm wondering how this all turned out. I'm looking to get dual 7970s for FCPX myself so I really want to know how the performances is. Is Final Cut stable? Quick?

Thanks!

 

[POSTpro]

@ thewisevaloo:

I do see a marked improvement in FCP X using 2 HD7970s. I did a non-scientific comparison between my hackPRO and my rMBP (late 2013 15" i7 2.3ghz with 16Gb ram & GT 750m) and the hackPRO rendered an identical timeline in exactly half the time as the rMBP. Now some may say this is not a fair comparison because of the two different type of machines but it was the validation that I needed. I'm sure that a more accurate comparison would be between one card verses two but I'm too busy (or lazy) at the moment to experiment with this.

There is, however, a down side to my configurations. I will state upfront that this could be do to my lack of clear understanding of proper configuration. I hope to do some testing on 10.10 to get optimal setting right. The fans on both video cards seem to run more often causing them to be quite loud. This is a destracting and can be a down right nuisance. Also, I'm not sure if having the HD4000 initialize first and remain active during computer operation is adversely affecting FCP X.

I would like to get my hackPRO to boot without using the HD4000 but I just haven't had the time to dig through all the forums. That is one beef I have with all the hackintosh community websites is that they are forum based and not knowledge based. I know that the technology is constantly changing and techniques and "fixes" come and go but googling is not the "be all end all" solution. I would like to commend jmonkey on his effort to keep his "iMessage fix" current, organized and relevant. I haven't dough into it like I need to because I too have the Apple block and would like to fix it but I'm putting everything off until 10.10. I've got projects that have to be done now and everything is "working enough" to get them done. I just know that my machine could run so much better with proper configuration.

 

[qbe]

in my testing, fcpx renders the same time with or without intel graphics (main monitor). i have no experience with dual 280x

amd 280x, 10.9.4, hack