Apple modular Mac Pro launch coming in 2019, new engineering group formed to guarantee fut...

189111314

Comments

  • Reply 201 of 269
    Marvin said:
    tipoo said:
    So fully 6 years between them by 2019, that's crazy to think of the gap left. That a very long time in silicon terms.

    The "pro workflow team" is encouraging. I'm hoping for myself it allows a lot of min/maxing, not fixed to relatively high end hardware on all parts like the iMac Pro. I need a lot of CPU for data science, but a GPU goes entirely unused, so I wouldn't need Navi Pro with HBM2 adding to the cost. 
    There's not much of a gap when you factor in the iMac Pro. If you were to spec out parts for a Mac Pro today, it would just be a headless version of the iMac Pro. Putting an iMac Pro on the floor and hooking it up to a 3rd party 4K display is close to what it would be. The only difference being able to switch components out, which people wouldn't do for another 3 or 4 years and wasn't possible with the 2013 model either.

    Their team of people working with pro workflows sounds like a great setup. Even contracting people to work on high-end visual effects jobs so they can sort out all the performance issues. That benefits all Mac users. Sometimes people assume more powerful hardware is needed when software runs slowly but as Apple has shown with FCP X vs Premiere, it can just be a case of making the software optimal. Apple has also demonstrated this with iOS products.

    The other factor mentioned in the article is the external GPUs. Apple showed the Techcrunch reporter Macbook Pros running with 1 and 2 external GPUs with 8K workflows. For people looking for that enthusiast-PC type setup, this works fine. GPUs are able to do real-time raytracing:



    That 24fps demo was done using quad Tesla V100 GPUs so around 60 TFLOPs of GPU performance. The CEO of Epic estimated around 40TFLOPs would be needed to do photoreal graphics in real-time ( https://www.digitaltrends.com/computing/40-teraflops-tim-sweeney-epic-photo-realism/ ). The current iMac Pro has 11 TFLOPs. Photorealism doesn't have to be real-time for post-production work but they are already moving to 7nm GPUs so in a couple of years there will be a doubling of GPU performance. This means ~4TFLOP MBPs and 20 TFLOP iMacs and hooking up an extra GPU or two via TB3 can bring it up to 60 TFLOPs.

    It's good to have the option of a modular tower system. It will likely allow up to double the performance of the iMac Pro but at price points around $8k-14k, it's not going to be the equivalent of the old towers that started around $1900. It's going to be an aspirational product that almost nobody will own. Most professionals will still be using iMacs and MBPs as their everyday workhorses. It's always nice to see new hardware designs though. I reckon they'll want to show it off at WWDC 2019 so over 12 months away. That puts it in a timeframe to get PCIe 5, maybe TB4:

    http://www.tomshardware.com/news/pcie-5.0-release-0.3,34720.html

    Interesting post, Marvin, as always...

    Your look at future GPU performance in the the next two years is intriguing.  We're looking at real time ray tracing within our grasp.

    A 20 TFLOP iMac and hooking up a couple of external gpus is appealing to me.  I have a pre-retina iMac (bought a year too early...) and the machine is holding up very well.  Like new.

    It doesn't look good.  About 9 years to get what they had in the first place.  Some will post pics of the Next Cube and the Quadra AND the Bauhaus Pro Mac.  Apple have some great hardware legacy in this space.  Couldn't they put two medium Vegas, the latest i9 10-18 core chip in the Mac Pro 'Can'???  If they can put it in the iMac Pro...

    Still, they don't want to.  Because it's flawed and aint selling to the diverse Pros demographics.  Fair enough.  But they could have to tide over the vociferous pros.  But again, they didn't like it from the outset.  People wanted room for several drives, at least a couple of gpus, a couple of cpus.  Apple took that away with the 'Can' and you can't take things away from people and expect them to be happy about it.

    A modular design with room for 2 cpus, 2 gpus and 3-4 SSD drives?  And take up less space than the old Bauhaus.  Why's it taking them so long.  For all the reasons people on this thread said.  Management.  Market moving in a way that was obvious to everybody but Apple.  Potential ARM move away from Intel.  

    Cynically, you could say that there was nothing to upgrade to from Intel or the GPU makers worth the money.  Minimal and glacial advances.  You can see what Apple have thought in iOS land they're better to do the entire thing themselves by investing in everything from ram, gpus to CPUS.  Giving the chips now entering the Mac from their customer chips division the writing is on the wall for Intel.

    So?  In the meantime there is the iMac Pro.  Very sexy.  (But isn't it just a CAN repackaged with a screen?)  I'm sure many tower advocates would love the innards of the iMac Pro without said Screen attached.

    I'd love to see them do a Mac Mini stacker system Infinity linked.  Want another 4 cores?  Buy another unit.  Plug in GPU of your choice.  Want ten of them?  That's £500 a pop.  Apple gets their money either way.

    I just see a more proprietary tower system inside a snugger case, maybe not as 3rd party upgradable as I'd like.  Apple wants locked down systems with big profits.

    I don't like the Tower price progression.  It went from £999-£1200 for the low end in the UK, to £1500...to £2000, to £2500, to £3000...  Then you get the 'mainstream' iMac floating up in price.  Then an 8 core iMac at £5000.

    I think the prices are somewhat ridiculous.

    You used to be able to buy an entry iMac for £595.  You can't now.  Apple had the 11 inch Macbook Air affordable.  Macbook Pro revision was insanely priced.  

    I'm interesting in what they do of course.  It may just be that 2019 fits in, like Marv' and others have said, with 7nm GPUs, TB 4, PCI 5(?) and higher core count cpus are finally on the move.  Moving planets of tech' into the alignment for a Mac Pro.  Add to that monitors...potentially going 8k.  The Dell 8k is remarkable at £3,500.  In two years what will it be?  I remember when Apple's 22inch LCD (was it?) at around £2000.  Remember when Jobs intro'd the 30 incher and it needed two gpu links to power it?  Love to see the Mac Pro debut with an 8K.  Maybe by then, gpus will be able to power an 8k monitor at 60fps?  AMD Navi?  That's two revisions to go on gpus.  (I know they're struggling at 4/5k at 50-60 fps at the moment...)

    Hopefully timing is everything.

    Lemon Bon Bon.
    avon b7
  • Reply 202 of 269
    SoliSoli Posts: 9,193member
    AFAIK Cook recently said the mini was an important part of Apple's future.  We need to see proof of the pudding, Tim. 
    How about that it still exists despite rumours of being canned since the PPC days since it's probably a low-volume seller compared to their laptops which are most expensive. It would be an ideal machine to get an ARM variant under the Mac mini Air moniker, or something similar.
  • Reply 203 of 269
    I don't know why Apple don't work with AMD.  Affordable 8 core cpus rather than the premiums they pay on Intel chips.  Imagine an 8 core Ryzen chip in the Mini or Mac Pro.  (An affordable Tower for £1500.  *Waves at Wizard.  You and me both, Mr. Wizard.)  There's a big gaming, VR, AI market for Apple to aim at.  Content is more popular than ever.  A tower Mac has a place.  But not at a price of £5k and higher!  £3500 would be the limit for me.  But I'd want an 8 core Mac Pro to start at £2500.  (The four core Mac Can was pricey at that!  Then they jacked it to 3k!)

    I don't believe they could make the Mac Pro can into a 'mini' Pro and put Ryzen and a medium Vega in it.  

    Instead we're paying £2000 for 4 core i7s...still...and lower end gpus from AMD.  (Yeesh.  It just means I keep my iMac longer Apple.)

    But that would mean Apple couldn't charge premium prices and keep a straight face...

    Lemon Bon Bon.
    cgWerks
  • Reply 204 of 269
    KITAKITA Posts: 191member
    Marvin said:
     
    That 24fps demo was done using quad Tesla V100 GPUs so around 60 TFLOPs of GPU performance. The CEO of Epic estimated around 40TFLOPs would be needed to do photoreal graphics in real-time ( https://www.digitaltrends.com/computing/40-teraflops-tim-sweeney-epic-photo-realism/ ). The current iMac Pro has 11 TFLOPs. Photorealism doesn't have to be real-time for post-production work but they are already moving to 7nm GPUs so in a couple of years there will be a doubling of GPU performance. This means ~4TFLOP MBPs and 20 TFLOP iMacs and hooking up an extra GPU or two via TB3 can bring it up to 60 TFLOPs.

    Interesting post, Marvin, as always...

    Your look at future GPU performance in the the next two years is intriguing.  We're looking at real time ray tracing within our grasp.

    A 20 TFLOP iMac and hooking up a couple of external gpus is appealing to me.  I have a pre-retina iMac (bought a year too early...) and the machine is holding up very well.  Like new.
    There are some factors that have been left out.

    First being, those four V100 GPUs output an additional 500 TFLOPS of mixed precision performance from the Tensor cores. The 60 TFLOPS (32-bit) are from the CUDA cores.

    Second, the GPUs are linked using NVIDIA's NVLink interconnects which offer 200 GB/s per GPU. For comparison, PCIe 3.0 x16 offers 32 GB/s and Thunderbolt 3 offers 5 GB/s.
  • Reply 205 of 269
    KoorstagKoorstag Posts: 2unconfirmed, member
    too little too late. I purchased a MacPro in early 2014. That cured me of ever buying another Mac.
    avon b7
  • Reply 206 of 269
    macplusplusmacplusplus Posts: 1,888member
    bkkcanuck said:
    Why is Apple still selling the cylinder Mac Pro? Who would buy it? This blog says Apple should have resurrected the cheese grater while they work on this new device. I think that’s ridiculous but if Apple is going keep selling the trash can it should contain the most up to date specs as possible.

    https://mjtsai.com/blog/2018/04/05/new-mac-pro-wont-arrive-until-2019/
    ... And to understand why the cheese grater may not come back we need to think about Thunderbolt.

    Thunderbolt is the standard that turns your PC inside-out.

    The main components of your PC are tied together with a bus called PCIe. Your graphics card, your SSD communicate with the CPU over PCIe.

    Now consider extending that PCIe bus over a cable outside the case of your PC: this is Thunderbolt. With Thunderbolt you can attach a desk-load of peripherals (RAIDs, monitors, external GPUs, network interfaces…) and make all of these communicate at speeds previously only available internally on your PC. Without Thunderbolt, you’d have to build a PC the size of that desk to include all of those peripherals. Thanks to Thunderbolt you can isolate the core of your PC from the peripherals and get a more refined and modern configuration with better thermal management and virtually unlimited expandability.

    The trash can Mac Pro is the power core at the center of such a modern configuration.

    When you are dealing with spinning rust, all thunderbolt does is add cost.  The "old" way is you just plug a rather high-performance SAS controller in the main box and then connect the external hard drive enclosure using the SAS cable.   The "new way" is to basically run the PCIe through thunderbolt, over a cable, to another box that has a power supply for the card, a PCIe slot (which could have been internal) ...  plug that same SAS controller in, then wire up the drives to it.  Basically, all you did was get the same performance by adding hundreds or more dollars to the cost.  

    And current tests on GPU cards -- show there is an impact on performance.  They perform well, but there is overhead with running it through Thunderbolt to another computer. There is a reason why the PCIe slots for graphics cards tend to be the closest to the CPU.  There can be performance degradation of up to 30% on a 1080Ti.
    At this point we cannot talk of "better" or "best", of pros and cons, but we can only notice a paradigm difference. Thunderbolt brings a different paradigm. This is Apple's way of doing things, some other brand may adopt another paradigm.

    The peripheral's own power supply may be an added cost for some, but for the Mac Pro it is a life saver because the core then may go with a smaller power supply. Add a powerful card to the enclosure, it will draw more power and will require a bigger power supply, which in turn will radiate more heat necessitating bigger fans, which will draw more power and again will require a bigger power supply to radiate even more heat... There is no solution to this equation in traditional desktop PC paradigm (Despite the presence of PSU's own fans, the forums are overloaded with "PSU overheating" screams). Thunderbolt cuts it short: to each peripheral its own power supply and fan.

    We to cut it short, must agree on one thing: Thunderbolt is Apple and is one of the main components of Apple architecture, that won't change in the near future. As a "pro", one has to be aware of these different paradigms and has to adopt the best that suits the needs.
    edited April 2018
  • Reply 207 of 269
    lorin schultzlorin schultz Posts: 2,739member
    Rayz2016 said:
    [...] the machine that will show up at the end of this extended incubation is not the machine that the “professionals” around here are asking for, namely a Dell box that just happens to run OSX.

    Maybe a Dell that runs macOS is a good idea? Maybe there's a reason not to offer such a device, but I can't think of one off the top of my head. Integrate Thunderbolt, let Jony pretty it up, job done.
    muthuk_vanalingamcgWerks
  • Reply 208 of 269
    lorin schultzlorin schultz Posts: 2,739member

    [...] The main components of your PC are tied together with a bus called PCIe. Your graphics card, your SSD communicate with the CPU over PCIe. Now consider extending that PCIe bus over a cable outside the case of your PC: this is Thunderbolt.
    Great in theory, except that Thunderbolt only manages a fraction of the speed an internal PCIe bus provides. It's not actually equivalent.

    It's a great idea, and certainly good enough for my particular needs, but I don't know if I'd be as happy if I had bandwidth-intensive tasks to perform.
    muthuk_vanalingam
  • Reply 209 of 269
    lorin schultzlorin schultz Posts: 2,739member

    bkkcanuck said:
    [...] The "new way" is to basically run the PCIe through thunderbolt, over a cable, to another box that has a power supply for the card, a PCIe slot (which could have been internal) ...  plug that same SAS controller in, then wire up the drives to it.  Basically, all you did was get the same performance by adding hundreds or more dollars to the cost.  

    And current tests on GPU cards -- show there is an impact on performance.  They perform well, but there is overhead with running it through Thunderbolt to another computer. There is a reason why the PCIe slots for graphics cards tend to be the closest to the CPU.  There can be performance degradation of up to 30% on a 1080Ti.
    Plus noise. One of the best things about Macs is how quiet they are. External card enclosures add a fan that ruins the silence.
  • Reply 210 of 269
    macplusplusmacplusplus Posts: 1,888member

    [...] The main components of your PC are tied together with a bus called PCIe. Your graphics card, your SSD communicate with the CPU over PCIe. Now consider extending that PCIe bus over a cable outside the case of your PC: this is Thunderbolt.
    Great in theory, except that Thunderbolt only manages a fraction of the speed an internal PCIe bus provides. It's not actually equivalent.

    According to your non-equivalence theory, all of those 4K and 5K Thunderbolt monitors are hoaxes then? Since they wouldn't be able to display 4K video as it is pumped out by the CPU/GPU.


    edited April 2018
  • Reply 211 of 269
    KITAKITA Posts: 191member

    [...] The main components of your PC are tied together with a bus called PCIe. Your graphics card, your SSD communicate with the CPU over PCIe. Now consider extending that PCIe bus over a cable outside the case of your PC: this is Thunderbolt.
    Great in theory, except that Thunderbolt only manages a fraction of the speed an internal PCIe bus provides. It's not actually equivalent.

    According to your non-equivalence theory, all of those 4K and 5K Thunderbolt monitors are hoaxes then? Since they wouldn't be able to display 4K video as it is pumped out by the CPU/GPU.


    He's literally saying, the PCIe 3.0 x16 offers 32 GB/s, while Thunderbolt 3 offers 5 GB/s. So an external GPU, for example, is now limited to 5 GB/s (2.5 GB/s each way).
  • Reply 212 of 269
    macplusplusmacplusplus Posts: 1,888member
    KITA said:

    [...] The main components of your PC are tied together with a bus called PCIe. Your graphics card, your SSD communicate with the CPU over PCIe. Now consider extending that PCIe bus over a cable outside the case of your PC: this is Thunderbolt.
    Great in theory, except that Thunderbolt only manages a fraction of the speed an internal PCIe bus provides. It's not actually equivalent.

    According to your non-equivalence theory, all of those 4K and 5K Thunderbolt monitors are hoaxes then? Since they wouldn't be able to display 4K video as it is pumped out by the CPU/GPU.


    He's literally saying, the PCIe 3.0 x16 offers 32 GB/s, while Thunderbolt 3 offers 5 GB/s. So an external GPU, for example, is now limited to 5 GB/s (2.5 GB/s each way).
    How did you get those numbers?
  • Reply 213 of 269
    Eric_WVGGEric_WVGG Posts: 646member
    Soli said:
    Eric_WVGG said:
    Damnit. This means that their new external display is probably another year off too.

    I know a lot of folks want the cheese grater back, but there's no reason for a computer to be that goddamned heavy. 
    1) To me, that seems more defunct than getting an AirPort mesh network.

    2) What about a compromise with a tower design that is much smaller?
    Apple acknowledged that there would be a new display alongside the Mac Pro promise.

    I honestly couldn't care less how big or small the tower is (hell, I'm exclusively a laptop guy). I was just always annoyed with how unnecessarily heavy the cheese grater models were.
    Soli
  • Reply 214 of 269
    SoliSoli Posts: 9,193member
    Eric_WVGG said:
    Soli said:
    Eric_WVGG said:
    Damnit. This means that their new external display is probably another year off too.

    I know a lot of folks want the cheese grater back, but there's no reason for a computer to be that goddamned heavy. 
    1) To me, that seems more defunct than getting an AirPort mesh network.

    2) What about a compromise with a tower design that is much smaller?
    Apple acknowledged that there would be a new display alongside the Mac Pro promise.

    I honestly couldn't care less how big or small the tower is (hell, I'm exclusively a laptop guy). I was just always annoyed with how unnecessarily heavy the cheese grater models were.
    I don't recall that. That's good to know. I wonder if the delay means that tech like Face ID will make its way into this future external display.
  • Reply 215 of 269
    KITAKITA Posts: 191member
    KITA said:

    [...] The main components of your PC are tied together with a bus called PCIe. Your graphics card, your SSD communicate with the CPU over PCIe. Now consider extending that PCIe bus over a cable outside the case of your PC: this is Thunderbolt.
    Great in theory, except that Thunderbolt only manages a fraction of the speed an internal PCIe bus provides. It's not actually equivalent.

    According to your non-equivalence theory, all of those 4K and 5K Thunderbolt monitors are hoaxes then? Since they wouldn't be able to display 4K video as it is pumped out by the CPU/GPU.


    He's literally saying, the PCIe 3.0 x16 offers 32 GB/s, while Thunderbolt 3 offers 5 GB/s. So an external GPU, for example, is now limited to 5 GB/s (2.5 GB/s each way).
    How did you get those numbers?
    Thunderbolt 3 has a total bandwidth of 40 Gb/s, convert to GB/s and we get 5 GB/s.

    B = byte
    b = bit 
    8 bits = 1 byte
    Solimuthuk_vanalingamcgWerks
  • Reply 216 of 269
    macplusplusmacplusplus Posts: 1,888member
    KITA said:
    KITA said:

    [...] The main components of your PC are tied together with a bus called PCIe. Your graphics card, your SSD communicate with the CPU over PCIe. Now consider extending that PCIe bus over a cable outside the case of your PC: this is Thunderbolt.
    Great in theory, except that Thunderbolt only manages a fraction of the speed an internal PCIe bus provides. It's not actually equivalent.

    According to your non-equivalence theory, all of those 4K and 5K Thunderbolt monitors are hoaxes then? Since they wouldn't be able to display 4K video as it is pumped out by the CPU/GPU.


    He's literally saying, the PCIe 3.0 x16 offers 32 GB/s, while Thunderbolt 3 offers 5 GB/s. So an external GPU, for example, is now limited to 5 GB/s (2.5 GB/s each way).
    How did you get those numbers?
    Thunderbolt 3 has a total bandwidth of 40 Gb/s, convert to GB/s and we get 5 GB/s.

    B = byte
    b = bit 
    8 bits = 1 byte
    Yes that's it, then what is the significance of those numbers in terms of GPU performance, what is the difference between using a graphics card internally on a x16 PCIe slot and using it in an eGPU TB 3 enclosure? Is that difference so big to justify using an internal slot? eGPU testing articles will certainly reveal that, I'm just asking without digging further.
  • Reply 217 of 269
    KITAKITA Posts: 191member
    KITA said:
    KITA said:

    [...] The main components of your PC are tied together with a bus called PCIe. Your graphics card, your SSD communicate with the CPU over PCIe. Now consider extending that PCIe bus over a cable outside the case of your PC: this is Thunderbolt.
    Great in theory, except that Thunderbolt only manages a fraction of the speed an internal PCIe bus provides. It's not actually equivalent.

    According to your non-equivalence theory, all of those 4K and 5K Thunderbolt monitors are hoaxes then? Since they wouldn't be able to display 4K video as it is pumped out by the CPU/GPU.


    He's literally saying, the PCIe 3.0 x16 offers 32 GB/s, while Thunderbolt 3 offers 5 GB/s. So an external GPU, for example, is now limited to 5 GB/s (2.5 GB/s each way).
    How did you get those numbers?
    Thunderbolt 3 has a total bandwidth of 40 Gb/s, convert to GB/s and we get 5 GB/s.

    B = byte
    b = bit 
    8 bits = 1 byte
    Yes that's it, then what is the significance of those numbers in terms of GPU performance, what is the difference between using a graphics card internally on a x16 PCIe slot and using it in an eGPU TB 3 enclosure? Is that difference so big to justify using an internal slot? eGPU testing articles will certainly reveal that, I'm just asking without digging further.
    That's a bit of a loaded question as a lot depends on the setup.

    Here's a 3D benchmark with an older dGPU.

    PCIe x16 3.0 (external monitor):



    Thunderbolt 3 (external monitor):



    Of course, there are more scenarios than the above. For example, when using an eGPU with a laptop, you either connect an external monitor to the eGPU directly, or, you use the laptop's internal display. When using the internal display, the bandwidth for the GPU over TB3 is cut even further to 2.5 GB/s and the performance will be even lower.

    The situation becomes even more complex for multi GPU setups, as even PCIe 3.0 x16 can be a bottleneck. As I pointed out above, NVIDIA, for their V100 GPUs, uses NVLink 2.0. In a four GPU configuration, each GPU has 200 GB/s of bandwidth over the NVLink.

    TL;DR - Thunderbolt 3 is not going to cut it.
    cgWerks
  • Reply 218 of 269
    macplusplusmacplusplus Posts: 1,888member
    KITA said:
    KITA said:
    KITA said:

    [...] The main components of your PC are tied together with a bus called PCIe. Your graphics card, your SSD communicate with the CPU over PCIe. Now consider extending that PCIe bus over a cable outside the case of your PC: this is Thunderbolt.
    Great in theory, except that Thunderbolt only manages a fraction of the speed an internal PCIe bus provides. It's not actually equivalent.

    According to your non-equivalence theory, all of those 4K and 5K Thunderbolt monitors are hoaxes then? Since they wouldn't be able to display 4K video as it is pumped out by the CPU/GPU.


    He's literally saying, the PCIe 3.0 x16 offers 32 GB/s, while Thunderbolt 3 offers 5 GB/s. So an external GPU, for example, is now limited to 5 GB/s (2.5 GB/s each way).
    How did you get those numbers?
    Thunderbolt 3 has a total bandwidth of 40 Gb/s, convert to GB/s and we get 5 GB/s.

    B = byte
    b = bit 
    8 bits = 1 byte
    Yes that's it, then what is the significance of those numbers in terms of GPU performance, what is the difference between using a graphics card internally on a x16 PCIe slot and using it in an eGPU TB 3 enclosure? Is that difference so big to justify using an internal slot? eGPU testing articles will certainly reveal that, I'm just asking without digging further.
    That's a bit of a loaded question as a lot depends on the setup.

    Here's a 3D benchmark with an older dGPU.

    PCIe x16 3.0 (external monitor):

    [removed]

    Thunderbolt 3 (external monitor):

    [snip]

    Of course, there are more scenarios than the above. For example, when using an eGPU with a laptop, you either connect an external monitor to the eGPU directly, or, you use the laptop's internal display. When using the internal display, the bandwidth for the GPU over TB3 is cut even further to 2.5 GB/s and the performance will be even lower.

    The situation becomes even more complex for multi GPU setups, as even PCIe 3.0 x16 can be a bottleneck. As I pointed out above, NVIDIA, for their V100 GPUs, uses NVLink 2.0. In a four GPU configuration, each GPU has 200 GB/s of bandwidth over the NVLink.

    TL;DR - Thunderbolt 3 is not going to cut it.
    Of course there is a reason Apple has soldered two GPUs onto the main board in Mac Pro. It might put a decent single GPU and suggest eGPU for the rest, but this is not the case. My point is, pushing the performance loss of a eGPU as a weakness of Thunderbolt doesn't do justice. Despite all those performance losses, eGPUs are still proposed as long as they offer better performance than the internal GPU:
    https://9to5mac.com/2017/11/27/egpu-amd-rx-vega-64-macos-high-sierra-beta-gpu-video/

    The FPS in your screen shots goes from 90.5 to 76.1, is that such a big deal? Can the gamer move at 90.5 fps? No, then this is irrelevant unless you're a FPS freak. That doesn't mean that eGPU should replace your PC's graphics card, as it doesn't mean that eGPU should replace Mac Pro's soldered dual GPUs (it can't). But as an expansion option Thunderbolt delivers, no one can deny this, it is not redundant or added cost. It deserves its place in your budget and in your machine.
    edited April 2018
  • Reply 219 of 269
    Eric_WVGGEric_WVGG Posts: 646member
    Soli said:

    I don't recall that. That's good to know. I wonder if the delay means that tech like Face ID will make its way into this future external display.
    I'm a little skeptical, my understanding is that the secure enclave needs to be tightly coupled to the motherboard. An externally connected device could be vulnerable to an attack "in the middle." This is why iMacs don't have TouchID. ((I could definitely be mistaken.))
  • Reply 220 of 269
    KITAKITA Posts: 191member
    KITA said:
    KITA said:
    KITA said:

    [...] The main components of your PC are tied together with a bus called PCIe. Your graphics card, your SSD communicate with the CPU over PCIe. Now consider extending that PCIe bus over a cable outside the case of your PC: this is Thunderbolt.
    Great in theory, except that Thunderbolt only manages a fraction of the speed an internal PCIe bus provides. It's not actually equivalent.

    According to your non-equivalence theory, all of those 4K and 5K Thunderbolt monitors are hoaxes then? Since they wouldn't be able to display 4K video as it is pumped out by the CPU/GPU.


    He's literally saying, the PCIe 3.0 x16 offers 32 GB/s, while Thunderbolt 3 offers 5 GB/s. So an external GPU, for example, is now limited to 5 GB/s (2.5 GB/s each way).
    How did you get those numbers?
    Thunderbolt 3 has a total bandwidth of 40 Gb/s, convert to GB/s and we get 5 GB/s.

    B = byte
    b = bit 
    8 bits = 1 byte
    Yes that's it, then what is the significance of those numbers in terms of GPU performance, what is the difference between using a graphics card internally on a x16 PCIe slot and using it in an eGPU TB 3 enclosure? Is that difference so big to justify using an internal slot? eGPU testing articles will certainly reveal that, I'm just asking without digging further.
    That's a bit of a loaded question as a lot depends on the setup.

    Here's a 3D benchmark with an older dGPU.

    PCIe x16 3.0 (external monitor):

    [removed]

    Thunderbolt 3 (external monitor):

    [snip]

    Of course, there are more scenarios than the above. For example, when using an eGPU with a laptop, you either connect an external monitor to the eGPU directly, or, you use the laptop's internal display. When using the internal display, the bandwidth for the GPU over TB3 is cut even further to 2.5 GB/s and the performance will be even lower.

    The situation becomes even more complex for multi GPU setups, as even PCIe 3.0 x16 can be a bottleneck. As I pointed out above, NVIDIA, for their V100 GPUs, uses NVLink 2.0. In a four GPU configuration, each GPU has 200 GB/s of bandwidth over the NVLink.

    TL;DR - Thunderbolt 3 is not going to cut it.
    Of course there is a reason Apple has soldered two GPUs onto the main board in Mac Pro. It might put a decent single GPU and suggest eGPU for the rest, but this is not the case. My point is, pushing the performance loss of a eGPU as a weakness of Thunderbolt doesn't do justice. Despite all those performance losses, eGPUs are still proposed as long as they offer better performance than the internal GPU:
    https://9to5mac.com/2017/11/27/egpu-amd-rx-vega-64-macos-high-sierra-beta-gpu-video/

    The FPS in your screen shots goes from 90.5 to 76.1, is that such a big deal? Can the gamer move at 90.5 fps? No, then this is irrelevant unless you're a FPS freak.
    What are you talking about? That's just a benchmark, the FPS is meaningless, the performance lost is what the focus should be on. On a newer card, like the GTX 1080 Ti, you're looking at a 30% decrease.

    However beyond gaming, we're talking about use for a workstation. If you used a modern workstation card, such as a Quadro GV100, you'd cripple its performance. You'd also rule out the potential for using multiple GPUs.

    cgWerksbkkcanuck
Sign In or Register to comment.