Comment by IFC_LLC
19 hours ago
I think that's an expected thing.
G5 was the thing. And companies were buying G5 and other macs like that all the time, because you were able to actually extend it with video cards and some special equipment.
But now we have M chips. You don't need video for M chips. You kinda do, but truthfully, it's cheaper to buy a beefier Mac than to install a video card.
Pro was a great thing for designers and video editors, those freaks who need to color-calibrate monitors. And right now even mini works just fine for that.
And as for extensions - gone are the days of PCIe. Audio cards and other specialized equipment works and lives just fine on USB-C and Thunderbolt.
I remember how many months I've spent trying to make Creative Labs Sound Blaster to work on my 486 computer. At that time you had to have a card to extend your system. Right now I'm using Scarlett 2i2 from Focusrite. It works over USB-C with my iPhone, iPad and Mac. DJIs mics work just as good.
Damn, you can buy Oscilloscope that works over USB-C or network.
It's not the Mac's or Apple's fault. We are actually live in the age where systems are quite independent and do not require direct installations.
> And as for extensions - gone are the days of PCIe. Audio cards and other specialized equipment works and lives just fine on USB-C and Thunderbolt.
Grumble grumble. Well, there used to more than audio cards, back before the first time Apple canceled the Mac Pro and released the 2013 Studio^H^H Trash Can^H^H Mac Pro.
Then everyone stopped writing Mac drivers because why bother. So when they brought the PCIe Pro back in 2019, there wasn't much to put in it besides a few Radeon cards that Apple commissioned.
The nice thing about PCIe is the low latency, so you can build all sorts of fun data acquisition and real time control applications. It's also much cheaper because you don't need multi-gigabit SERDES that can drive a 1m line. That's why LabVIEW (originally a Mac exclusive) and NI-DAQ no longer exist on Mac.
USB-C oscilloscopes work because the peripheral contains all the hardware, so it doesn't particularly matter that the device->host latency is high. They also don't require much bandwidth because triggering happens inside the peripheral, and only the triggered waveform record is sent a few dozen times per second.
> It's not the Mac's or Apple's fault. We are actually live in the age where systems are quite independent and do not require direct installations.
It is, and we don't. Maybe you don't notice it, but others do.
> USB-C oscilloscopes work because the peripheral contains all the hardware, so it doesn't particularly matter that the device->host latency is high.
Yeah, that's basically the way accessories have gone. Powerful mcu's and soc's have gotten cheap enough to make it viable. Makes me a little sad though, I liked having low latency "GPIO's" straight to software running on my PC (but I'm thinking as far back as the parallel port... love how simple that was).
It's not just that - anything working with analog signals benefits hugely from not living inside the complete EM interference nightmare of the computer case.
Well there is https://www.crowdsupply.com/eevengers/thunderscope
With USB4/TB you can get quite far in both latency and throughput. Actually there are network adapters with TB connection that are just TB to PCIe adapters and PCIe network card.
> gone are the days of PCIe.
My GPU, NVMe drives and motherboard might disagree.
The top Mac Studio has six thunderbolt 5 ports, each of which is a PCIe 4.0 x4 link. Each is a 8GB/sec link in each direction, which is a lot. Going from x16 down to x4 has less than a 10% hit on games: https://www.reddit.com/r/buildapc/comments/sbegpb/gpu_in_pci...
Your example uses GTX1080, which is a very old GPU. Current flagship consumer GPU will take a harder hit on low bandwidth PCIE.
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PCIe 4.0 x4 is going to be a huge bottleneck, even recent SSDs have more throughput (they use PCIe 5.0) never mind GPUs.
Gaming isn't what people are using Mac Studios for. Thunderbolt also isn't a substitute for OCuLink.
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Yeah 80GB/s total I/O bandwidth is a lot for a Mac, but desktop PCs have been doing 1TB/s (128x PCIe5) for years (Threadripper etc).
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- GPU is integrated into the SoC - Surprisingly, it is possible to plug a drive into a TB/USB port
…so what do you actually need PCIe for?
High-end Macs have moved to PCIe 5.0 speeds in their internal drives. Thunderbolt 5 is not fast enough to get the same performance from external ones.
Thunderbolt is also too slow for higher-end networks. A single port is already insufficient for 100-gigabit speeds.
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To have lots of them plugged together, high end audio cards, electronics integrations, disks with having cables all over the place.
Things that aren’t graphics cards, such very high bandwidth video capture cards and any other equipment that needs a lot of lanes of PCI data at low latency.
but what about second GPU?
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Video capture
I/O expansion
Networking
> gone are the days of PCIe
Thunderbolt is external PCIe.
No, oculink is external PCIe.
Thunderbolt can kinda-sorta mimic PCIe, but it needs to chop up the PCIe signal into smaller packets, transmit them and then put them back together and this introduces a big jump in latency, even when bandwidth can be rather high.
For many applications this isn't a big deal, but for others it causes major problems (gaming being the big one, but really anything that's latency sensitive is going to suffer a lot).
I’m at peace with the memory and PCIe basically flows over thundebolt. At one point external gpus were a thing. I think what I’d really love would be a couple or few m.2 slots in my studio for storage expansion.
Does M5 series have better video encoding chip/chiplet/whatever it is called than M4 series? Because while I’m happy with my M4 Pro overall, H.264 encoding performance with videotoolbox_h264 is disappointingly basically exactly the same as a previous 2018 model Intel Mac mini, and blown out of water by nvenc on any mid to high end Nvidia GPU released in the last half-decade, maybe even full decade. And video encoding is a pretty important part of video editing workflow.
If you mean editing ProRes is a better fit, if you mean final export software always beats hardware encoders in terms of quality, if you mean mass h.264 transcoding a Mac workstation is probably not the right place though.
> gone are the days of PCIe
This is a wild and very wrong take.
Just about every single consumer computer shipped today uses PCIe. If you were referring to only only the physical PCIe slots, that's wrong too: the vast majority of desktop computers, servers, and workstations shipped in 2025 had physical PCIe slots (the only ones that didn't were Macs and certain mini-PCs).
The 2023 Mac Pro was dead on arrival because Apple doesn't let you use PCIe GPUs in their systems.
> This is a wild and very wrong take.
That's what happens when you quote only part of a statement. Taken in context, it was referring to a very real decline in expansion cards. Now that NICs (for WiFi) and SSDs have been moved into their own compact specialized slots, and Ethernet and audio have been standard integrated onto the motherboard itself for decades, the regular PCIe slots are vestigial. They simply are not widely used anymore for expanding a PC with a variety of peripherals (that era was already mostly over by the transition from 32-bit PCIe to PCIe).
Across all desktop PCs, the most common number of slots filled is one (a single GPU), and the average is surely less than one (systems using zero slots and relying on integrated graphics must greatly outnumber systems using more than one slot).
Even GPUs themselves are a horrible argument in favor of PCIe slots. The form factor is wildly unsuitable for a high-power compute accelerator, because it's ultimately derived from a 1980s form factor that prioritized total PCB area above all else, and made zero provisions for cards needing a heatsink and fan(s).
> Ethernet and audio have been standard integrated onto the motherboard itself for decades
Unless the one it comes with isn't as fast as the one you want, or they didn't integrate one at all, or you need more than one.
> Across all desktop PCs, the most common number of slots filled is one (a single GPU), and the average is surely less than one (systems using zero slots and relying on integrated graphics must greatly outnumber systems using more than one slot).
There is an advantage in having an empty slot because then you can put something in it.
Your SSD gets full, do you want to buy one which is twice as big and then pay twice as much and screw around transferring everything, or do you want to just add a second one? But then you need an empty slot.
You bought a machine with an iGPU and the CPU is fine but the iGPU isn't cutting it anymore. Easy to add a discrete GPU if you have somewhere to put it.
The time has come to replace your machine. Now you have to transfer your 10TB of junk once. You don't need 100Gbps ethernet 99% of the time, but using the builtin gigabit ethernet for this is more than 24 hours of waiting. A pair of 100Gbps cards cuts that >24 hours down to ~15 minutes. If the old and new machines have an empty slot.
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My post Mortem sentiments exactly. The lack of Nvidia GPU support for the M series Mac Pro models kneecapped the platform for professionals. If Apple had included that in those they’d be the defacto professional workstation for many more folks working in AI tech.
On the other hand it forced developers to invest more in Metal which looks like an investment starting to bear fruit.
Plus modern interconnects like CXL are also layers on top of PCIe, and USB4 supports PCIe tunnelling. PCIe is a big collection of specifications, the physical/link/transaction layers can be mixed and matched and evolved separately.
I don't see it disappearing, at most we'll get PCIe 6/7/etc.
Thunderbolt is PCIe running over a cable.
Sure, with expensive line drivers to send the data 1+ meters, instead of 10ish cm. And with only 2 channels instead of up to 16.
Yes, I know; this is part of what I was implying when I said "Just about every single consumer computer shipped today uses PCIe."
I don't understand how this is a response to anything I said.
Yup the 4090 and SoundBlaster ZXR in my AM5 7800X3D system would both like to upvote your reply.
Sound card works fine on USB2 (RME for example has cards on USB2 that can manage 30/30 io at 192khz without issue at low latency if you have the CPU to deal with the load)
With USB3 you have 94 i/o…
For years pci has not been mandatory for audio. UAD, Apogee, RME and other high end brands will push you to them. Or even only provide them as usb device… even Thunderbolt is not needed here.
And that’s been the case for a while! My Fireface UC from 15 years ago can deal with 16 channels at 96khz at 256 sample. On PC and Mac.
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Scarlett 2i2 has been amazing for me, I’d say unbeatable in terms of quality/price ratio.
it's not just about pcie, it's socketed memory and disks. I guess disks are just pcie technically - but memory sockets are great. hell, in the pro chassis I am surprised they didn't opt for a socketed cpu that could be upgraded.
The latest M2-based Mac Pro did not take socketed memory AIUI.
This is correct; Apple has refused to implement socketed memory on any M-series machine.