Hacker News Reader

Comment by chx | Hacker News Reader

There's an amazing website and community if you are interested in external GPUs at https://egpu.io/ . Both for Mac and PC you will find guides, explanations etc.

There's also an eGPU subreddit and I wrote a sticky on U series chips, PCIe lanes and Thunderbolt 3 https://www.reddit.com/r/eGPU/comments/7vb0gg/u_series_chips... which is more interesting for PCs than Mac.

View on HN

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.

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

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%.

I thought for sure you'd be wrong, but nope!

https://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_1080_...

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

I think it’s the other way around. Assets are loaded at initialization anyhow.

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.

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

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

>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.)

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.

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.

I'm pretty sure they only tolerate developers given the poor state of the MacBook keyboard design.

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.

I have a Dell U3415W w/ a second 24" 1080 for my desktop, and to be honest, I'm often more focused and comfortable working on my 13" MBP in a comfortable chair instead.

Xcode is far better on the desktop but for terminal + vim + broswer type work, the laptop screen is perfectly reasonable.

As for using OSX, I've just gotten comfortable with it. I never have to fiddle anymore. I always wait to upgrade OS's and it generally just stays out of my way. Windows is annoying and I haven't found a comparable fussless linux laptop yet (and I'm actively looking because I won't be able to keep avoiding that stupid touchbar).

Their investment in Metal and their own mobile GPU hardware suggests to me that they do, and that they want to own the technology from top to bottom.

https://developer.apple.com/metal/

https://techcrunch.com/2017/09/12/the-new-iphone-8-has-a-cus...

Are mobile GPU efforts relevant to MacOS and desktop GPU work?

They will be if they start putting them in Macs.

I think we agree on that. I'm certain they will. But that also agrees with my initial statement, no?

For Apple, they want thin and light. Mobile is both things, and the thought of designing a system that can cope with the 200W+ draw of desktop GPU parts doesn't even factor in to their thinking.

They're tossing a bone to the users who need actual heavy-duty GPU power by talking about the ability to use external cards, but (in my opinion) considering the cost and performance issues that come with that approach, it is more an admission that they truly don't care about that segment of the market than an actual solution.

https://www.apple.com/imac-pro/specs/ — released just a few months ago.

The AMD Vega 64 has got to push a few hundred watts.

Microsoft has the Surface Book 2 with GTX 1060 and they must be looking at that as competition for the high end MacBook Pro.

I did a little poking around out of curiosity.

According to: https://www.anandtech.com/show/11717/the-amd-radeon-rx-vega-...

Vega 64 has a board power rating of 295W.

According to the imac pro tech specs from the link you provided, it has an idle draw of 64W, and a peak draw of 370W for the entire system.

Unless I'm mistaken, that seems to imply that there has to be a good deal of throttling between the CPU & GPU to come in at that power budget. (The specs also note an additional 50W(!) of potential draw for fans alone if the imac is operated in a warm environment.)

Am I mistaken?

Not arguing, just hashing out my understanding. Your point regarding the Surface Book 2 and the 1060 makes sense. It does look like I was technically incorrect about them not engineering to a 200+ watt GPU, although I do wonder what sustained draw it can handle thermally compared to a full desktop part, and how much that would affect performance.

> Vega 64 has a board power rating of 295W.

John from Mantiz reported 650W peak. Surely only for milliseconds but still. https://egpu.io/forums/implementation-guides/2014-mac-mini-v... it is absolutely not in the interests of an eGPU chassis manufacturer to report figures which hinder their own sales so I believe him.

Similarly, someone with an awful lot of AMD knowledge (AMD employee?) on the egpu.io forums pretty much begged people not to try the Vega 64 in a Sonnet 550 hinting at similar problems https://egpu.io/forums/thunderbolt-enclosures/sonnet-says-th... and saying a solution is in the works.

Sonnet http://www.sonnettech.com/support/kb/kb.php?cat=524&expand=_... says the Vega 64 is only supported in the 650 box -- which was just released pretty much because of the necessity to support the Vega 64. Something is rotten in Denmark: 650W power supply supports up to 375W card (up to 8-pin + 8-pin power connectors) plus provides additional 100W of peak power.

Since 2003, they’ve always made their best hardware solutions as mobile devices. Desktops have been more for specific use cases - almost exclusively geared toward niche use cases. Ie Mac Pro and iMac Pro. It seems more than a little odd to me. They don’t really offer a seam less transition from desktop to laptop to handheld. Even the old iPods felt more naturally integrated into their desktop usage than current.

I wish they offered a full size, liquid cooled but fans included high end/Nvidia GPU desktop. A system that’s not afraid to be noisy because their users aren’t seeking that. Then sync up the less hardware intensive tasks between their mobiles. But maybe that desktop market died in their eyes.

I think the market for liquid-cooled desktops is pretty niche itself. It just happens to be a niche that Apple is not interested in. Whereas for the majority of people, a regular iMac is just fine.

> 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.

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.

'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.

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.

> 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.

It's a very helpful community. I used the instructions to add a 750ti to my wife's Mac Mini. It was painless, and the 3D modeling software that used to crash her computer runs great.

For the sake of archives: if the 750ti is a good level for your application (which it often is) then Lenovo has a really, really small Thunderbolt Graphics Dock containing an 1050. Reports of success on Mac varies. Read the relevant subreddit wiki https://www.reddit.com/r/thinkpad/wiki/intro for a nice discount on it.

Reply on news.ycombinator.com