euqlaog

Thanks a lot for your answer. So with that being said. The purpose of the riser is to supply power to the PCIe GPU, so in this case with external PSU we won't need to connect power to Atikio box at all. Am I correct? And can you tell me which raiser do you preferred?

Yes, a powered riser (with two 12V wires + two ground wires) provides 75W to the golden fingers of the GPU and also enough power to the AKiTiO board + TB controller, you don't need the AKiTiO's power adapter at all. I bought the riser from eBay, and it has a capacitor.

You can alternatively try molex-to-barrel adapter (http://forum.techinferno.com/enclosures-adapters/8317-%5Bguide%5D-making-molex-barrel-adapter.html#post113069) and attach the GPU directly to the x16 slot without a riser.

That is a very nice work. I have a Sapphire HD 7950 3GB laying around. So to start this project I need these items:

- AKiTiO Thunder2

- PSU

- PCIe riser

What is the setup schematic looks like? 2 six pin connector to GPU, power plug to PCIe riser, and connector to power up PSU? Am I correct? Please let me know. Thank you

Thanks! I don't know if your GPU is compatible with AKiTiO, you may have better luck with Nvidia cards. Yes, this is a common eGPU setup with a powered riser (4pin molex from PSU), GTX780 has one 8pin and one 6pin power connector. You need to do that "paper clip trick" to power on PSU, a guide for this is here.

Great news and great guide. thx!

But the fan noise is a no go imho…

I updated my post regarding the noise issue. Netstor sent me a new PSU with lower fan speed for free. That's awesome service! It's not as quiet as SFX PSU, there is that little "buzzing" at idle, but notable improvement when the GPU was stressed. I ran Valley benchmark for an hour on OS X and half an hour on Windows, and the system was stable, no sign of crash or kernel panic at 80C degrees, 2560x1140 ultra quality mode with a 4K display, enclosure's top cover placed. On windows, reference GTX 980 fan speed was 53% (~2215 RPM) after half an hour of benchmarking.

Not sure if it's entirely safe, but if you're building a custom enclosure you could add a large fan and make sure that it blows cool air to the PSU, that way maybe the PSU fan won't be needed and you can disable it.

Streacom support told that it would be difficult to actively cool their fanless Flex PSU because there are not such air vents. The other problem is that most of them don't have 2x6pin power plugs. Some people have changed the fan of their SFX size PSU, but my limit is there.. I would never take a risk of overheating the PSU, the manufacturer has designed to control fan speeds / air flow safely.

Would be awesome to be able to source something like this to power the card:

FSP400-70LQ-FSP GROUP :::PC Power Supply, IPC Power Supply, Open Frame, Adapter :::

With a custom enclosure it would make for a small egpu solution.

Thanks! The problem with these Flex ATX PSUs is the small 4cm fan, which is noisy compared to normal ATX PSUs. Netstor sent me a new modified Flex PSU and I will update the NA211TB implementation within a few days how they succeeded to lower fan speed.

Alright, sounds good!

I tried method 2 today, but the gpu always crash when I enter games etc.

Is this because the akitio cant supply enough power? i get driver crash + bsod.

Most likely. There is also a risk of ground loop when using two power supplies.

Hmm, you're not using a riser with the gtx 780?

Do you think I could do the same with a gtx 970?

Actually I haven't had problems in detecting the cards running on 25W x16 PCIe slot + molex-to-barrel plug: Gigabyte 750Ti, EVGA GTX 780 OC, Gigabyte GTX 980 reference model. No experience of GTX 970. Powering method 2 is not recommended, always use just the ATX PSU. With a powered riser Windows doesn't always detect the card at first, but when the card is attached directly to the x16 slot, it seems to always show up as basic display adapter and then you can install the Nvidia driver. But after driver installation, please use a powered riser because there is high risk to melt the yellow/black wires touching the GPU. The back plate of GTX 980 becomes very hot, I quickly removed the card as I noticed plastic smell!

Hello Goalque,

Thanks for the explanation everything seems very clear.

I will be trying out this implementation soon.

On the OS X side of things : no breakthrough? Still doesn't work on Iris Pro only models?

Cheers,

Still the same, external monitor is not detected with a Mid 2014 15" MBPr Iris Pro only on OS X. However, the GPU is detected under system report, so CUDA calculation might be possible.

Someone who likes to make the most compact and quiet setup, could consider the fanless PSU I mentioned earlier

ZF240 – Fanless 240W ZeroFlex PSU | Streacom

And make a custom outer shell. They answered that it is possible to use molex to 6pin, but max load on the 12V line combined is 168W. It might be enough for some non OC versions of the GTX970 (145W TDP).

@Tech Inferno Fan What do you think? On their web page they are saying “To put things in perspective, if the ZF240 was actively cooled, it would be rated as a 450W power supply.“ But that statement is quite misleading because there are no airflow vents, so would be difficult to actively cool it. The first european distributor is in Germany.

Regarding those smaller GTX970 cards, some of them are too high in size to fit inside the AKiTiO enclosure if you like to use the outer shell as well. For example: GV-N970IXOC-4GD 129mm (include bracket). I measured it might fit alone, but even if you have a low-profile power plugs, it would be quite impossible. Making a custom size outer shell with some fan would be recommended in any case because there is a risk to melt the yellow/black wires touching the GPU.

Remember that those tests were done with highest quality settings (custom), and they are not comparable to my just updated 4K results. I used default high/ultra/ultimate in Tomb Raider and default medium/high/ultra in BF4:

http://forum.techinferno.com/implementation-guides/7580-%5Bguide%5D-2014-15-macbook-pro-iris-gtx780%4016gbps-tb2-akitio-thunder2-win8-1-a.html#post103029

I did a few additional test in Tomb Raider to see how close TB2 is x4 speed in reality:

AKiTiO + GTX 780 OC 6GB (3840 x 2160, highest settings, NoAA, TressFX disabled):

29,1 (min)

42 (max)

34,7 (average)

AKiTiO + GTX 980 4GB reference card (3840 x 2160, highest settings, NoAA, TressFX disabled):

30 (min)

42,7 (max)

36,4 (average)

AKiTiO + GTX 980 4GB reference card (1920 x 1080, highest settings, 4xAA TressFX disabled):

44,6 (min)

78 (max)

60,7 (average)

All the tests done with a Samsung UHD 28" Monitor + DisplayPort cable. GTX 780 OC 6GB is very close to GTX 980 4GB at higher resolutions. The other conclusion is that TB2 is slower than x4 1.1 in Tomb Raider when we look at the average FPS values, but we have to take into account that 2014 MBPr 15" is not a desktop computer. However, it performs very well when playing with default quality settings, and with the newest 344.65 driver, you will get a few more FPS.

I figured out that this box is really the modder’s dream in addition to the 24pin power connector: a standard Flex ATX PSU (150mm x 81.5mm x 40.5mm), which is easily replaceable.

The PSU length can be much more than 150mm because no obstacles at the bottom space. Streacom has just released a fanless 240W PSU: ZF240 – Fanless 240W ZeroFlex PSU | Streacom

With this PSU, the only audible component would be the GTX 980 reference blower, which has pleasant soft “whoosh” sound. I already sent an enquiry and waiting for the answer if it’s possible to use splitters to feed up to 75W for two 6pin plugs via MOLEX and SATA. I am a bit worried as the specs says 12V@14A.

The highest peak I saw was 205W under 3DMark11 and Fire Strike with the NA211TB + GTX 980 when metered from the power strip. The reference GTX 980 draws only 177W/185W under gaming/torture test according to this review:

Nvidia GeForce GTX Watchdogs Results

If the fanless PSU won’t work, there are still other Flex ATX PSUs to choose from, for example this:

FSP Europe - Fortron Source - Professional

Does anyone have experience of some Flex PSU to recommend? Preferably with two 6pin plugs. By the way, GTX 750Ti keeps the original PSU fan noise more acceptable level.

Wow… ok. So it is a problem of the mid 2014 MBPr? That is crazy. Ok than I will just use it in Windows 8.1.

Yes, the 15" Iris Pro only. Different GPUs, monitors, DVI/HDMI/Display Port cables, OS X versions, resolutions tested, but always black screen on external monitor. I am not sure what causes this. It's really odd, because some users have posted that it works with a 15" MBPr Iris Pro + 750M.

@wasi88: Would you like to test if your MBPr 15" Iris Pro only (late 2013) with the Nvidia web driver and kext modifications identifies the external monitor via eGPU?

I got my system working in Windows 8.1.

MacBook Pro Retina 15" (Iris only, mid 2014) with a EVGA GTX 970 FTW and a AKiTiO.

But I can't get any screen detected in OSX… the card is installed an listed but no display (DVI or HDMI) is recognized. So in the system report the card is listed as a GTX 970 but any screen connected by DVI/HDMI is NOT listed and not working.

Any ideas?

Answered here, there is no workaround for this model on OS X.

Hey, did you test your Gigabyte 750Ti any further? I'm using this version (Gigabyte GTX750 OC). It seems to be benchmarking fine (no crashes), but did crash once in CS:GO (black screen when using ultra high settings). I'm powered the same way you were, with the included Akitio AC adapter and a separate PSU for the 6-pin.

Yes, but not for longer period or gaming. I am not powering my systems with two PSUs anymore, after I got knowledge that there is a risk of ground loop. By doing that, AKiTiO's PSU made buzzing sound at higher frame rates. Additionally, when Gigabyte GTX 980 was attached directly to the AKiTiO's PCIe board, the 4pin yellow/black wire almost melted, because the backplate of reference GTX 980 becomes very hot. Luckily, I noticed it early and no much harm happened. Even if 25W from the x16 slot seems to be enough with EVGA GTX 780 OC w/ ACX and Gigabyte 750Ti, and they run cooler, I recommend to use a powered riser with ATX PSU, no other power sources.

@goalque, thank you for posting this info.

The first question I asked is how much for the Netstor NA211TB? As you know Thunderbolt2 has for the most part been obscenely priced until the AKiTiO Thunder2 was released. Unfortunately the Netstor product doesn't help there. Google tells me a Netstor NA211TB costs ~US$899 for the older 250W model, making it a peer to http://forum.techinferno.com/enclosures-adapters/7872-us%24979-sonnet-echo-express-iii-d-enclosure-16gbps-tb2.html#post107170 and with a similar feature set.

So when I compare it against the Sonnet III-D I ask why would an eGPU user go for the Netstor product? The Sonnet enclosure has to me more appeal due to it's smaller footprint, quieter fan and more ready availability. The only sticking point against the III-D being how to draw 225W or 300W from the III-D's PSU given it comes only with a 6P PCIe connector allowing 150W power draw. We show at http://forum.techinferno.com/enclosures-adapters/7872-us%24979-sonnet-echo-express-iii-d-enclosure-16gbps-tb2.html#post107170 how to do that easily with just PCIe cable splitters (up to 225W) and/or use of the EVGA Powerboost product to draw 75W from a few slot (up to 300W total).

@goalque, can you provide any good reason why an eGPU user would get the Netstor over the Sonnet III-D?

Yes, AKiTiO is at the moment most inexpensive choice for eGPU purposes and recommended, but I would remind that Sonnet Echo Express III-D is not the only option in the category of enclosures to fit full length card and noticed that people have had problems running GTX 780Ti with the simple splitter method as told here and here.

GTX 780 OC (250W TDP) passed performance tests with the 6pin & 6+2pin power cables of the NA211TB's 300W PSU. Some people have been asking on this forum where is the plug-and-play solution if the price doesn't matter, and NA211TB comes to very near answering this question. The price of this updated unit is the same as the 250W version, but generally it is slightly cheaper than Sonnet III-D, for example:

£674.40 vs £744

$849 vs $979

Most of us the price is too expensive, I know. Netstor is very responsive to my emails and seems that they are interested in developing their product towards eGPU use as discussed here earlier. Maybe Apple and Intel are keeping the prices high. I am also waiting for the day when there will be a product with only single x16 slot, and no 25W power limitations as AKiTiO has, and with the price near $200-$300. That would sell like hotcakes. I hope that my report of NA211TB will make some competition and eventually prices will become lower. III-D seem to be quite equal to NA211TB but I cannot much compare them, because I have no experience of III-D. If there wasn't the noise issue, I would absolutely choose NA211TB because of these reasons (mostly for DIY people):

1) A standard 24pin power connector making it very easy to use any ATX PSU. Sonnet has not this connector. My implementation was not the first one, another is here with the Silverstone's enclosure: maxserve blog: Thunderbolt (no english version available).

To make NA211TB very quiet, you just have to unplug the 3pin wire connected to the TB card (it just gives a signal to the PSU to power on), use a modular ATX/SFX PSU with its original 24pin power cable, where the other end to the PSU is connected as it is and the other end is modified like this:

Nothing else.

2) Two open-ended PCIe slots supporting x16 cards, which can be mounted directly on PCIe board (without the enclosure). When using the x4 slot, there remains 2 free slots to use for anything you like. With the III-D, this is not possible because there is only one x16 slot and the two other x8 slots are not open-ended as I googled some pictures (correct me if not true).

It's a pity that the NA211TB's 300W PSU has that small fan making the noise. Maybe it's not a problem for someone using headphones, but for me it is unfortunately. One of the main reasons I like eGPUs is keeping the system quiet because with a normal PC there is always a CPU generating heat inside the enclosure and more fans. MBPr 13" is totally silent and it won't throttle during heavy gaming. I also wanted to point out how eGPU performs with a 4K display. I will update the FPS result table of my AKiTiO implementation.

Discussing with Netstor Technology, I convinced that their Thunderbolt 2 to PCIe expansion enclosure was capable of running high-end GPUs, and ordered one to introduce. The product name is Netstor NA211TB. They recently updated the PSU to provide 300W output, shared by three free PCIe slots, where one PCIe 2.0 x8 slot is open ended, supporting double wide PCIe x16 cards. 4th slot is reserved for a Thunderbolt card. What makes this device unique is the auxiliary power cable configuration: two PCIe 6+2pin and one 4pin cable. As far as I know, none of the competitors provide that as of yet. You are not restricted to low-power Maxwell architecture cards, and moreover, there is one slot free beside double wide GPU, making it possible to mount for example PCIe SSD. No extra power supply, case or cable modding, or warranty-voiding methods. Just simply setting up and keeping desk tidy.

My testing setup consists of the following components:

• Netstor NA211TB (Thunderbolt 2, 300W), also marketed by HighPoint Technologies
• Gigabyte GeForce GTX 980
• Apple MacBook Pro 13” Retina, 2.4Ghz Intel Core i5 (Late 2013) on Windows 8.1 and OS X 10.10 Yosemite (14A389)
• Apple 2m Thunderbolt cable
• Samsung 28” UHD LED Monitor (U28D590D)
• Display Port cable

Optional: Silverstone Strider ST45SF-G 450W 80+ Gold Modular Power Supply (v. 2.0)

[ATTACH=CONFIG]13040[/ATTACH]

[ATTACH=CONFIG]13041[/ATTACH]

[ATTACH=CONFIG]13048[/ATTACH]

At first sight the outer shells are made of sturdy and well finished aluminium, resembling surface of the Mac computers. Cards are easy to install by removing the upper shell. Keeping a GTX 980 reference card in my hands feels like a real brick compared to other GPUs I have had. It’s a perfect companion with this case, because of the blower style fan. If you chose a card having sink plates vertically that would most likely result in heat problems because there are no upper air vents. Therefore, a reference card or a GPU cooler that blows hot air horizontally is recommended. The reference GTX 980 is noticeably more silent than the EVGA GTX 780 w/ ACX cooler, and the minor buzzing sounds from the electronic parts won’t disturb at higher frame rates. There is a hot-swappable 80mm fan in front of the box, which speed can be adjusted. The only drawback is the 300W PSU, which is very loud during heavy gaming and for my ears, it’s quite loud on idle as well. Tiny 4cm fan spinning fast cannot be very silent. Netstor has got my feedback, and they will discuss with engineers to find balance between temperature and fan speeds. Except the noise, I didn’t found much more disadvantages to say.

So how to solve this noise issue? Well, I have very good news for those who are DIY enthusiasts. The PCIe board has a standard 24pin power connector and I was able run this box with the Silverstone’s SFX 450W PSU and modified power cable. I surprised that it was more silent with the GTX 980 than with the GTX 780. The reason must be lower power consumption.

You can run the GPU in any of the free three slots: SLOT3 (open-ended x8), SLOT2 (x8 with a riser) and SLOT1 (x4, open-ended). If the PCIe card you like to install in SLOT1 has x8 or x16 golden fingers, SW1-2 must be switched to ON position. SW-1 switched to OFF means that SLOT1 will run as PCIe Gen2 signal. Slot numbers are marked on PCIe board. I didn’t notice performance drop when running GPU on SLOT1, but it was just a quick test and of course in this case the PCIe board has to be removed out of the enclosure. Does the SFX size PSU fit inside the enclosure? It does fit in front of the case if you first remove some parts as shown below:

[ATTACH=CONFIG]13042[/ATTACH]

Unfortunately upper metal bars and side cables cannot fit inside and another problem is the location of AC power plug. Both problems might be solved by using a shorter GPU and turning the PSU to position where power cables point out front and AC plug back. However, cooling the case becomes concern, because the PSU blocks airflow. This is a temporary solution to keep my system quiet. The original PSU can be removed out to make more room for the cables underneath.

How about performance? Let’s the numbers tell their story:

[ATTACH=CONFIG]13043[/ATTACH]

3DMark Vantage: 32677 (graphics) 3DMark11: 13585 (graphics) 3DMark Fire Strike: 10918 (graphics)

Unigine Valley Benchmark 1.0 (GTX 780 OC 6GB / GTX 980 comparison on Yosemite)

[ATTACH=CONFIG]13044[/ATTACH]	[ATTACH=CONFIG]13045[/ATTACH]
[ATTACH=CONFIG]13046[/ATTACH]	[ATTACH=CONFIG]13047[/ATTACH]

Setup procedure for Win8.1

• Install Win8.1 on Boot Camp partition.
• After installing Windows, download and install all the Windows updates.
• Check if you already have latest Boot Camp drivers and if not, download and install them (Boot Camp Support Software 5.1.5640)
• Install a device driver for Samsung UHD 28” Monitor: Support - UHD Monitors U28D590D | Samsung Monitors
• Install Optimus support: [URL]http://forum.techinferno.com/diy-e-gpu-projects/8106-%5Bwip%5D-2013-13-macbook-pro-gtx760%4016gbps-tb2-akitio-thunder2-win8-1-osx10-10-a.html#post110489
[/URL]
• After successfully logged in Windows and seeing the GPU as basic display adapter under device manager, install the latest Nvidia drivers (344.48).

Big thanks to @Evo* for discovering 100% Optimus detection method. You just need to boot alt/option key down and select Win8.1 partition.

The step 5 is almost compulsory in order to log in Windows. If you are seeing basic display adapter in device manager instead of Iris, reinstall Boot Camp Support software and Nvidia drivers, both Iris and GTX 980 will be listed there then.

If you happen to have preinstalled Nvidia drivers and haven't done step 5, both internal and external screen will stay black when GTX 980 is attached to SLOT3, but in SLOT1 external screen should show up. So you can reinstall Nvidia drivers in SLOT1, then again in SLOT3, and GTX 980 should be detected via DVI, but I encountered problems via Display Port. GTX 780 was detected in SLOT3 straight away. If you like to try this, I recommend to using a riser instead of removing the PCIe board out of the enclosure. If you have done step 5, all the problems with Display port will vanish and internal screen will be accelerated on Win8.1. When external monitor is set as default display on OS X, internal screen will be accelerated too when running Unigine Valley Benchmark test.

Setup procedure for OS X 10.10 (14A389)

1) Download Nvidia web driver 343.01.01f03 from here. 2) Open up terminal and modify the downloaded file to pass system checks. The quickest way is by using Terminal:

[FONT=Menlo]

pkgutil --expand WebDriver-343.01.01f03.pkg expanded.pkg

[/FONT]

3) Right mouse click expanded.pkg and choose “Show Package Contents”, right click “Distribution” file and choose Open With TextEdit. Then modify the InstallationCheck() method to return always true:

        function InstallationCheck()

        {

            //if (!validateHardware()) return false;
            //if (!validateSoftware()) return false;


            return true;
        }

4) Save the “Distribution” file. 5) [FONT=Menlo]pkgutil --flatten expanded.pkg flattened.pkg[/FONT] 6) Double mouse click flattened.pkg and install Nvidia web driver. 7) Modify three kexts (NVDAStartup.kext, IONDRVSupport.kext, AppleHDAController.kext), a good walkthrough is here. 8) Final steps are:

[FONT=Menlo]

sudo nvram boot-args="kext-dev-mode=1 nvda_drv=1"

[FONT=Open Sans], [/FONT][/FONT]restart MBP and if not working yet, see the system log and try

[FONT=Menlo]sudo touch /Extensions [/FONT][FONT=Menlo]sudo kextcache -system-caches[/FONT]

13” MBPr is a good choice for most of the games, because for example BF4 was playable 3840x2160@40-60FPS with medium settings. At lower resolutions it didn’t give much more frames, and when using high settings there was a big drop. If you have Windows gaming in mind and don’t care about eGPU on OS X side, and want high and ultra settings, go for a 15” MBPr Iris Pro, because its quad core processor will give great performance boost and 4K gaming.

References I would like to give acknowledge:

maxserve blog: How to recognize GPGPU via Thunderbolt external PCIe Box at MacOSX

[URL]http://forum.techinferno.com/implementation-guides/2728-%5Bguide%5D-2012-13-macbook-pro-retina-gtx570%408gbps-tb1-th05-win7-64-a-3.html#post37481[/URL]

EDIT: Netstor sent me a new PSU with lower fan speed. It's still the 4cm fan and the physical factor means the sound it is not as quiet as Silverstone's SFX size PSU with the 8cm fan - there is that typical, minor buzzing sound at idle. However, they succeeded to reduce the noise level significantly when I ran benchmark tests at 80C degrees. Actually, I did not notice much PSU noise increase when the GPU was stressed, the GPU itself ran at higher fan speeds to exhaust hot air from the back. To reduce the noise more, you may try some sound dampening material inside the enclosure.

Mid 2014, so no chance with Iris only model and OS X?

Yep, I have tried various methods without success. Thanks for confirming. I haven't seen any report of the 15" Iris Pro late 2013 model, but it does work with 13" Iris (late 2013). I really hope that Apple hasn't disabled this feature with their new firmwares.

Haha, what I did was plugged out TB2 without shutting down the OS X 10.9.5, then the OS X crashed. When the display showed 'Kernel panic', pulled in the plug then press return button. After the OS X restarted, the external display worked.

Doesn't work with Iris Pro only model, I guess you have the 750M.

Any ideas why im not getting a display output?

NVidia drivers are installed and working (loading)

System Info looks good

Monitor on DVI port but i can't get any display...

[ATTACH=CONFIG]12977[/ATTACH]

[ATTACH=CONFIG]12978[/ATTACH]

Macbook Pro Retina Iris only

It's the same problem with Mid 2014 15" MBPr Iris Pro, external monitor is not detected. Would you clarify what year model, late 2013 or mid 2014? According to the picture, you actually have Iris Pro.

I do modify 3 kext. And the external monitor with GTX 780 does not work every time.

When external monitor using GTX 780 does not work, I disconnect the TB2. Then the OSX 10.9.5 crashed and restarted itself.

Then external monitor works.

Is it harm for my laptop, when I disconnect the TB2 without shutting OSX down?

Thanks for you clarification. You can try also just selecting restart from the main menu as Mark did. Some thunderbolt devices are hot-pluggable, but eGPUs are not. Disconnecting the TB cable will cause system crash and restart, I don't think it harms your hardware. The same can happen, when Mac goes to sleep mode and eGPU turns off. I found an interesting note from Apple regarding new iMacs and Mac mini (Late 2014) with Boot Camp:

"The iMac (Retina 5K, 27-inch, Late 2014) and the Mac mini (Late 2014) support “hot pluggable” Thunderbolt devices using Windows 8 or 8.1 (both as 64-bit only)."

Thunderbolt ports and displays: Frequently asked questions (FAQ)

Now we have the first proof that Mid 2013 MacBook Pro with GTX750M + eGPU enables the external monitor on OS X. Did you use these steps to enable it?

http://forum.techinferno.com/implementation-guides/6088-%5Bguide%5D-2011-13-macbook-pro-gtx660%4010gbps-tb1-sonnet-ee-pro-win8-1-osx-10-9-1-a-2.html#post87145

Mark said here that with the Late 2013 15" 750M + OS X, an additional reboot was required sometimes. There does not exist an eGPU solution for Mid 2014 Iris Pro Only model with OS X. I have tried to enable external monitor via eGPU many ways without success. I wonder how the dGPU affects this issue? For those who are considering whether to choose a model with the dGPU or Iris Pro only, should keep this in mind:

- Iris Pro only -> internal screen Optimus support on Win8.1, black screen output to external monitor on OS X (someone who knows there is workaround, please say)

- GTX750M -> no internal screen Optimus support on Win8.1, accelerated external monitor on OS X

If I have understood it correctly some users are reporting that they need an extra restart of Windows to enable Optimus with other brands than EVGA (example post - see more information in this post).

I have noticed this same, here is the 3rd report that Optimus is not working perfectly with a MSI card:

http://forum.techinferno.com/implementation-guides/7879-%5Bguide%5D-2013-13-macbook-pro-gtx970%4016gbps-tb2-akitio-thunder2-win8-1-a.html#post107838

I guess he never got it working when external display connected, but some success without external display. There might be other brands supporting Optimus as well as EVGA. Sonnet SEL & EVGA is a perfect combination.

First of all, thanks for the guide! I have just ordered the AkiTiO box and it should arrive next week and I'm picking up my MBP 2014 with Pro Iris next week as well

I have some questions I hope you don't mind answering.

1. Is it correct that I don't spot a PCI-e riser?

2. I'm going for a GTX 780 as well. Do you know if Asus, Zotac or the other brands will work just like the EVGA you have or?

3. How stable is it for gaming? I'm hoping to shoot some bad guys when Far Cry 4 launches!

4. Did you manage to get the external monitor to work in OS X?

Thanks!

You are welcome!

1) Correct. I haven't experienced any power problems with EVGA GTX 780 6GB version when attached directly to the AKiTiO's x16 slot. But for safety reasons, I recommend using a powered riser. Keeping a GPU near the PCIe board may result in melting the 4-pin yellow/black wire connecting PCIe board and Thunderbolt card. ACX coolers keep my card temperatures low though and they blow the heat up and down.

2) I would recommend GTX970, they don't need that 250W wattage input (at least the models that are not overclocked) and therefore produce less heat. You will find good options from the main discussion thread: http://forum.techinferno.com/enclosures-adapters/7205-us%24200-akitio-thunder2-pcie-box-16gbps-tb2.html. EVGA brand is not compulsory, but may have better Optimus support. I have seen on this forum that with MSI cards, there have been some problems with Optimus (correct me, if it's not true).

3) As mentioned on this thread, it is stable in BF4 DM / 64 players. Nowadays I don't play much, so cannot say about other games.

4) No. I have examined this a lot: different graphics cards, monitors, DVI/HDMI/Display Port-cables, kextwizard, reinstalling OS X, resetting PRAM, deleting com.apple.windowserver files. The GPU is detected under system report fine, but missing the monitor info. Also system boot logs refer to the same, the monitor is not detected for some reason. It only outputs black signal when login screen appears (normally at this stage, the external screen should be extended and visible). I have concluded that the reason is the new Mac hardware which is not fully compatible with the Nvidia web drivers.

I am having some discussion privately here about this. For all those people who read this and own MBPr 15" Iris Pro (Late 2013 / Mid 2014) and AKiTiO, I would appreciate another confirmation if you have the same result with OS X. I have got some feedback that with a late 2013 15" (Iris Pro + 750M) it should work occasionally.

Ok thanks! I need sometimes both the screens just for more space. When gaming, the sharp retina screen is my favourite over 1080p external

Optimus worked flawless. Just booted without an external display and ran some benchmarks.

Optimus results (internal vs. external display):

3dMark_FireStrike (Graphics Score): 8785 vs. 9763 (90% performance of external display)

3dMark_11(Graphics Score): 13687 vs. 12981 (95% performance of external display)

Valley_ExtremeHD(Score): 1922 vs. 2104 (91% performance of external display)

Optimus results (Optimus vs. Hackintosh):

3dMark_FireStrike (Graphics Score): 8785 vs. 12367 (71% performance of Hackintosh)

Valley_ExtremeHD(Score): 1922 vs. 2274 (84,5% performance of Hackintosh)

Those numbers indeed look very good! Does it work with both screens (external extended)? Which steps required? Of course, the best internal/external performance is got when the other screen is disabled.