garytyler

It would work about 30% of boots. - - - Updated - - - Also, I know what you mean about selling the TB display. The only benefit is the ports though and it's nice to not be limited to needing a TB output.

I have not been able to get my Thunderbolt Display to work consistently with my Akitio setup. I ended up selling it and buying a regular 27" Apple Cinema Display instead. I think what Nando says in a few threads is the case... basically, the BIOS gets confused and makes some random decisions at boot. This leads to the sometimes black screen boot and it means the display signal is routed to what seems to be a random port. With my 27" Display, it will work with mini-Displayport or Displayport via adapter. What I found is that the display output routes to either my empty TB port on my MBP Retina or it routes to the Displayport on my eGPU. So, when I boot my machine, either the display turns on or I switch the cable to get it to turn on. This allows me to use my display 100% of the time, but sometimes I have to switch a cable. It's worth it in the end.

Is this the issue that causes the boot to black screen half the time when I boot with 2 eGPUs daisy chained? Interesting. I wonder if I should be running a PCIe splitter instead. I'm just doing GPU rendering so it should't slow me down.

MVC, Do you think the EFI mod would allow the on board Thunderbolt port to provide consistent display output on my 2014 15" MBPr + 750M during eGPU operation? If so, I'll mail you 2 cards.

After this post, I'll need to spend the evening catching up on work but I wanted to report some more findings. All of my tests are using both of my TITAN cards daisy chained because my goal is to have both of them running satisfactorily, which I believe I've found a pretty good solution for. If I did these tests again, I would have a few displays setup with each connection so I could tally the functional display outputs on each boot. I didn't have all of that gear at once so I tested HDMI yesterday and Display Port today. Also, I am using the Default OS X Graphics Driver for these tests. My past experiences are that it runs the cards about identical to the Nvidia Web Drivers in regard to display output but the Default OS X Graphics Driver seems to have better stability during CUDA rendering. The regular GTX TITANs have full support from the default drivers but note that the TITAN Black or TITAN Z does not. They both load as NVIDIA Chip Model. I have tested all of these myself. Components: -2014 15" MBPr + 750M OS X 10.10.1 -Corsair RM750 PSU -x2 Akitio Thunder2 Expansion Boxes -x2 GTX TITANS (x1 Asus, x1 EVGA) -x2 Powered Risers *Display output through Display Ports on TITANS worked 12 out of 16 boots. Only one of the cards would provide output at a time and which one seems to be designated at random. It doesn't seem to have any relation to whether the display was plugged in during boot or not. *HDMI provides approximately the same results but sometimes the "chosen" port is the proprietary HDMI port on the laptop instead of the HDMI ports on the eGPUs and the success rate seems to be a little bit higher, possibly because of there being 3 ports instead of 2. *DVI has not been tested extensively but I have tried them maybe 5 times with zero success. *The spare TB2 port on the laptop will output to a Thunderbolt Display approximately 30% of the time. ***I acknowledge this data collection may not be presented to the scientific standards of some users and I don't care because this forum is not my full time job. If it is misleading or not based on good evidence, that is a different story and I will happily remove or edit the info. Many of us only have so much we can give and I expect most users here are not interested in being full time eGPU makers. We are building these machines to assist in other interests. TechInferno is not academia and if it were, I probably wouldn't want to help out at all. With that said, I am very thankful. I just think it's silly to be on here ridiculing people for things like typos or seeming "amateur."

HDMI output on the GPU is about as consistent as output on the proprietary TB2 and HDMI ports. Both are basically like rolling dice. I haven't gotten anything from the DVI ports though. I feel comfortable saying they won't work. I don't have a good cable/display setup handy to test the Display Port through the cards. I don't remember the name of it but I'm running the Corsair 750 with a little plug device I picked up at this computer thrift store in my neighborhood. It accomplishes the same thing as the paperclip trick. Maybe it's the PLEX switch you mention above but I don't remember the name. I've got a Kill-A-Watt meter as well. With both cards rendering, it pulls between 410 and 450 watts. I just wish I could figure out how to get a consistent response from any one of these ports. I don't care for enhanced graphics, just need large display to do work on.

I meant MBPr 15". I am certain I've got all the kext mods correct. I've been using this setup for a month or so. The GPUs show up both as GTX TITAN in System Profiler. They are currently powered via powered risers (also powering the Akitios via the risers) from a Corsair 750. I have tried every arrangement for powering them that I know (Akitio's included power supply & molex>barrel plug) and each combination brings the same results with this setup. By "external output, period" I am referring to display output from the free TB port and the HDMI port on the laptop. By "period" I mean to highlight that the issue with display output is not only with the ports on the eGPU, but also the proprietary ports on the MBPr while having the eGPU connected. I have read the same reports from other TechInferno users but there hasn't been any resolution found. - - - Updated - - - Maybe I should add this in the other thread. I'm not sure. Once everything is booted, it runs great 98% of the time. Sometimes I get a freeze during intense GPU operation that is a different type of freeze than I have seen with my applications. The screen freezes and the cursor stays as a pointer and I must reboot myself. - - - Updated - - - One more thing. I am running the most recent Web Drivers but I discovered my TITANs will load the same in the System Profiler without it. They also produce essentially equivalent benchmarks and render performance on the Default OS X Graphics Driver. I expect you already knew this but it's pretty cool.

Just a note, my 2014 MBPr GT 750M does not just have issues with external output through the eGPU but also from the proprietary ports on the laptop. This includes the free TB2 port and the HDMI port. Each of them function maybe 1 out of 4-5 boots. I have also found that the eGPU (2x Amities + 2x GTX Titans) will give output through HDMI with approx. the same frequency (1 of 4-5 tries).

MVC, thanks for all the help and info. I am wondering if you might have suggestions for getting a display output straight from the MBPr to work. I'm running a MBPr 2014 w/ GT 750M, 2x Akitios with 2x GTX TITANs and often have to boot up to 10 times before I can get my display to boot. I don't want accelerated graphics. I'm just rendering with Octane. I keep seeing in your posts and others that the MBPrs have issues getting external output from the eGPUs but I have issues getting external output period, whenever an eGPU is connected. I'm not sure if this is a separate issue or the same, but if it's all the effect of the same cause, it might help to discuss it that way? Just a thought. Looking forward to what gets learned here, as I love my MBPr for video editing and want to be able to rely on it (mores) for animation rendering as well.

I realize this, just thought it might somehow add some insight. I realize it may be completely unrelated problems but the symptoms are pretty much exactly the same so this info may help someone findan answer. Who knows. I'm not running them on SLI. I'm running them for Octane Render software. No need for SLI.

My latest setup is giving me these exact issues. It's a 2014 MBPr 750M with 2 Akitios, 1 with a TITAN and 1 with a TITAN Black via daisy chain. I can run one of these cards on it's own with no problem, but I'm hoping to run both of them. I am getting boot about 60% of the time, and black screen the rest. Maybe this info will help with problem solving, who knows. 1x TITAN = boots every time 1x TITAN + 1x TITAN Black = same black screen boot issues reported elsewhere in this thread

I've used 3 different cards with my MBPr and Akitio now. They can all be used with external monitors bit you must boot with the monitor unplugged and plug it in within the first few seconds after your desktop loads. When I learned this, I was just remembering that even without an eGPU, my Thunderbolt Monitor wouldn't turn on until my desktop loads during bootup and thinking it was worth a try. It works almost every time. If it doesn't work for some reason, I just reboot. It is a little annoying but it works and it's worth it. I would expect that there is a modification we could use with the tunneling commands in the kext files that would change this because my guess is that the issue has to do with the fact that the Apple Thunderbolt monitor and some of the Thunderbolt hubs are the only peripherals that could tunnel to other devices through Thunderbolt before the kext modification. Now that I think about it, some of the extra Kexts may not be necessary for use without enhanced graphics. I'll try that in the next few days and post my results. I may be onto something here.

I think that answers the question. The prompt lists what is used in the test. It was just the Titan Z. Here's another that includes the 750M. This seems like exactly what the scores would be if only 1 core was being used. Thanks for this. I had been scouring for info but the benchmark thing seemed like it would not bring me the answers I was looking for. Glad I did it! http://www.mediafire.com/view/acu3y6cxac3nf4t another member just posted in the Octane forums a screenshot of both Titan Z cards loaded with drivers so I know it's possible. I'll give an update.

I don't know much about benchmarking. Had some programs running in the background and such but this is the score I got in Luxmark testing only the Titan Z: Simple File Sharing and Storage.