6 ms·

I've heard that external GPUs have too much latency to be that useful for a lot of applications. What I'd like to see is a Mac with a nice big fat Nvidia GPU.

I've heard that external GPUs have too much latency to be that useful for a lot of applications. What I'd like to see is a Mac with a nice big fat Nvidia GPU. Why can't I buy a Mac with a 1080 ti? My suspicion is that Apple wants to get into the GPU game themselves, and bring some of the expertise from their mobile GPU team to laptops and desktops. That'd be great, if they actually released something competitive. So far, they haven't, and Mac users, who would love to pay for better technology, are left out in the cold as a result.

grecy 9y ago
> My suspicion is that Apple wants to get into the GPU game themselves They said the upcoming Mac Pro will be "modular", which I think is a clear sign it will have external GPUs, or certainly will lean heavily in the direction of encouraging users with a heavy GPU workload in that direction.
rtpg 9y ago
I thought that eGPUs work through stuff like thunderbolt, where you're basically using a PCI Express port, so the slowness would only come from the length of cables relative to an internal GPU? Or is this a misunderstanding on my part
- jeswin 9y ago
  Slowness is also due to thunderbolt being PCIe x4 as opposed to x16 - x4 has a fourth of the bandwidth. Games however don't max out x16 usually, so you'd lose about 25%.
  - Viper007Bond 9y ago
    I thought for sure you'd be wrong, but nope! https://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_1080_PCI_Express_Scaling/24.html https://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_1080_...
    - rtpg 9y ago
      My theory would be that most of the transfer is about assets and games have more of a memory constraint rather than a bandwidth constraint in that space
      - extralego 9y ago
        I think it’s the other way around. Assets are loaded at initialization anyhow.
        ZeikJT 9y ago
        Used to be the case but most open-world games stream in assets nowadays and you can see the lower resolution assets fade out as the higher fidelity assets finish loading on the fly. In games that want to load fast loading a save game might drop you into a pretty low fidelity world and then start loading in the higher res assets.
kalleboo 9y ago
There's some kind of animosity between Apple and Nvidia which is why you only see AMD hardware in Macs
hajimuz 9y ago
Another possible reason is battery life，which is hardly be over 16hours if they choose NVIDIA independent graphic cards.
Baeocystin 9y ago
>My suspicion is that Apple wants to get into the GPU game themselves My suspicion is that they barely even want GPUs, which they seem to see as annoying sources of heat and noise, getting in the way of their ultimate vision of an imac so thin you could use it as a kitchen knife. (I wish I were kidding about this, but I am not.)
- dbg31415 9y ago
  My suspicions is that they barely even want devs (given the new "Pro" line) -- they absolutely don't want gamers using their pretty laptops. (I wish I were kidding about this, but I am not.) Ok... so we had a bunch of the new MBPs at work and kept having keyboard issues (like 50% of the team complained about the keyboards and had keys that stuck within the first 3 months). I brought one machine in to the Apple Store and was scolded for eating while using the computer. "Hey Guys, I'm sorry that humans weren't in your target audience focus groups -- the new butterfly keys are amazing!" Wasn't even my machine... just doing a favor for a friend. Ugh.
  - pjmlp 9y ago
    They want devs that care about Apple systems, Objective-C and Swift devs, not devs that use it as pretty UNIX. That was only when they needed to survive.
    - TrueTom 9y ago
      I'm pretty sure they only tolerate developers given the poor state of the MacBook keyboard design.
      - yborg 9y ago
        What professional developer codes full-time on a laptop keyboard and screen? The ones at work are all on dual-27" displays and external keyboard and mouse. I personally disagree with making engineering compromises on the human interface to make things a few mm thinner, but the results speak for themselves. People keep buying them because Apple has succeeded in the number one goal of branding - their products are instantly recognizable as luxury goods. So if you're a pro developer who doesn't care about the branding, you just buy a different laptop that has the attributes you do care about. If developers abandoning the Macbook Pro because of nerd rage about low key travel and the ESC key cause sales to plummet, I'm betting Apple will change the keyboard. I'm also betting that the sales won't plummet.
kayoone 9y ago
Latency is not the issue, as Thunderbolt 3 is a direct PCIe connection. Only bottleneck might be bandwidth, usually you get 10-20% performance loss with an eGPU but with a 1080Ti that's still plenty of performance.
- monocasa 9y ago
  'Direct' PCI-E connections can still be pretty slow. It's way more like a network than a traditional bus. The fail0verflow guys bridged PCI-E over a 115200 baud UART and it still worked.
nsommer 9y ago
Unfortunately I don't remember where I read this, but I've once read somewhere that Apple refuses to use nvidia gpus because nvidia doesn't give Apple access to the driver source code. AMD on the other hand does.
monocasa 9y ago
> My suspicion is that Apple wants to get into the GPU game themselves, and bring some of the expertise from their mobile GPU team to laptops and desktops. Eh, desktop and mobile GPUs are radically different beasts. My thought is that since they write their own drivers, and they obviously don't have the resources they once had in the MacOS team (see all of the crap High Sierra went through), they simply can't support more than a few SKUs.

grecy 9y ago

> My suspicion is that Apple wants to get into the GPU game themselves They said the upcoming Mac Pro will be "modular", which I think is a clear sign it will have external GPUs, or certainly will lean heavily in the direction of encouraging users with a heavy GPU workload in that direction.

rtpg 9y ago

I thought that eGPUs work through stuff like thunderbolt, where you're basically using a PCI Express port, so the slowness would only come from the length of cables relative to an internal GPU? Or is this a misunderstanding on my part

jeswin 9y ago
Slowness is also due to thunderbolt being PCIe x4 as opposed to x16 - x4 has a fourth of the bandwidth. Games however don't max out x16 usually, so you'd lose about 25%.
- Viper007Bond 9y ago
  I thought for sure you'd be wrong, but nope! https://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_1080_PCI_Express_Scaling/24.html https://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_1080_...
  - rtpg 9y ago
    My theory would be that most of the transfer is about assets and games have more of a memory constraint rather than a bandwidth constraint in that space
    - extralego 9y ago
      I think it’s the other way around. Assets are loaded at initialization anyhow.
      - ZeikJT 9y ago
        Used to be the case but most open-world games stream in assets nowadays and you can see the lower resolution assets fade out as the higher fidelity assets finish loading on the fly. In games that want to load fast loading a save game might drop you into a pretty low fidelity world and then start loading in the higher res assets.

kalleboo 9y ago

There's some kind of animosity between Apple and Nvidia which is why you only see AMD hardware in Macs

hajimuz 9y ago

Another possible reason is battery life，which is hardly be over 16hours if they choose NVIDIA independent graphic cards.

Baeocystin 9y ago

>My suspicion is that Apple wants to get into the GPU game themselves My suspicion is that they barely even want GPUs, which they seem to see as annoying sources of heat and noise, getting in the way of their ultimate vision of an imac so thin you could use it as a kitchen knife. (I wish I were kidding about this, but I am not.)

dbg31415 9y ago
My suspicions is that they barely even want devs (given the new "Pro" line) -- they absolutely don't want gamers using their pretty laptops. (I wish I were kidding about this, but I am not.) Ok... so we had a bunch of the new MBPs at work and kept having keyboard issues (like 50% of the team complained about the keyboards and had keys that stuck within the first 3 months). I brought one machine in to the Apple Store and was scolded for eating while using the computer. "Hey Guys, I'm sorry that humans weren't in your target audience focus groups -- the new butterfly keys are amazing!" Wasn't even my machine... just doing a favor for a friend. Ugh.
- pjmlp 9y ago
  They want devs that care about Apple systems, Objective-C and Swift devs, not devs that use it as pretty UNIX. That was only when they needed to survive.
  - TrueTom 9y ago
    I'm pretty sure they only tolerate developers given the poor state of the MacBook keyboard design.
    - yborg 9y ago
      What professional developer codes full-time on a laptop keyboard and screen? The ones at work are all on dual-27" displays and external keyboard and mouse. I personally disagree with making engineering compromises on the human interface to make things a few mm thinner, but the results speak for themselves. People keep buying them because Apple has succeeded in the number one goal of branding - their products are instantly recognizable as luxury goods. So if you're a pro developer who doesn't care about the branding, you just buy a different laptop that has the attributes you do care about. If developers abandoning the Macbook Pro because of nerd rage about low key travel and the ESC key cause sales to plummet, I'm betting Apple will change the keyboard. I'm also betting that the sales won't plummet.

kayoone 9y ago

Latency is not the issue, as Thunderbolt 3 is a direct PCIe connection. Only bottleneck might be bandwidth, usually you get 10-20% performance loss with an eGPU but with a 1080Ti that's still plenty of performance.

monocasa 9y ago
'Direct' PCI-E connections can still be pretty slow. It's way more like a network than a traditional bus. The fail0verflow guys bridged PCI-E over a 115200 baud UART and it still worked.

nsommer 9y ago

Unfortunately I don't remember where I read this, but I've once read somewhere that Apple refuses to use nvidia gpus because nvidia doesn't give Apple access to the driver source code. AMD on the other hand does.

monocasa 9y ago

> My suspicion is that Apple wants to get into the GPU game themselves, and bring some of the expertise from their mobile GPU team to laptops and desktops. Eh, desktop and mobile GPUs are radically different beasts. My thought is that since they write their own drivers, and they obviously don't have the resources they once had in the MacOS team (see all of the crap High Sierra went through), they simply can't support more than a few SKUs.