Marvin

kestral said:

What is Apple doing about ChatGPT / Bard and the AI wars? This is huge. Apple hired an AI guy, time for him to earn his pay.

tenthousandthings said:

programmer said:

I haven't seen it mentioned here that there is a fundamental architectural difference between the Apple Silicon GPU and pretty much every other GPU architecture (except Imagination/PowerVR):  it is a tile-based architecture.  If you look at the Metal programming manual, there are numerous differences in how the two types of architectures need to be dealt with by the application.  Those differences will be even more severe at the OS/driver level.  Apple is quite aggressive at dropping old hardware in order to reduce their software burden (given, as mentioned above, software lifecycles are actually longer than hardware delivery cycles), and I would imagine they want to get to a place where (in Metal 4 or 5) they can completely focus on their hardware's tile-based architecture, and not have to accommodate AMD/nVidia designs.  Same applies to the rumoured "ray tracing" support [...]

Great post, really helpful, thank you for taking the time to write it. Pardon me if I'm wrong about this, but isn't everyone moving toward tile-based/chiplet-based architectures, not just Apple? I know AMD's RDNA 3 architecture uses "chiplets" (AMD's term for tiles). So even while Apple is moving toward dropping support in Metal 4 or 5 for older architectures, the rest of the industry is moving along with them. So accommodating AMD's current, chiplet-based 7000-series designs (and future designs) in the Apple Silicon lattice Mac Pro wouldn't necessarily be too much of a burden?

mikethemartian said:

It doesn’t really matter since there are many Mac users who won’t use a display unless it is officially anointed by Apple.

tht said:

cgWerks said:

tht said:
… The big issue, how do they get a class competitive GPU? Will be interesting to see what they do. The current GPU performance in the M2 Max is intriguing and if they can get 170k GB5 Metal scores with an M2 Ultra, that's probably enough. But, it's probably going to be something like 130k GB5 Metal. Perhaps they will crank the clocks up to ensure it is more performant than the Radeon Pro 6900X …

The devil is in the details. I’ve seen M1 Pro/Max do some fairly incredible things in certain 3D apps that match high-end AMD/Nvidia, while at the same time, there are things the top M1 Ultra fails at so miserably, it isn’t usable, and is bested by a low-mid-end AMD/Nvidia PC.

I suppose if they keep scaling everything up, they’ll kind of get there for the most part. But, remember the previous Mac Pro could have 4x or more of those fast GPUs. Most people don’t need that, so maybe they have no intention of going back there again. But, I hope they have some plan to be realistically competitive with more common mid-to-high end PCs with single GPUs. If they can’t even pull that off, they may as well just throw in the towel and abandon GPU-dependant professional markets.

If only they can keep scaling up. Scaling GPU compute performance with more GPU cores has been the Achilles heel of Apple Silicon. I bet not being able to scale GPU performance is the primary reason why the M1 Mac Pro was not shipped or got to validation stage. On a per core basis, 64 GPU cores in the M1 Ultra is performing at little over half half (GB5 Metal 1.5k points per core) of what a GPU core does in an 8 GPU core M1 (2.6k per core). It's basically half if you compare the Ultra to the A14 GPU core performance. And you can see the scaling efficiency get worse and worse when comparing 4, 8, 14, 16, 24, 32, 48 and 64 cores.

The GPU team inside Apple is not doing a good job with their predictions of performance. They have done a great job at the smartphone, tablet and even laptop level, but getting the GPU architecture to scale to desktops and workstations has been a failure. Apple was convinced that the Ultra and Extreme models would provide competitive GPU performance. This type of decision isn't based on some GPU lead blustering that this architecture would work. It should have been based on modeled chip simulations showing that it would work and what potential it would have. After that, a multi-billion decision would be made. So, something is up in the GPU architecture team inside Apple imo. Hopefully they will recover and fix the scaling by the time the M3 architecture ships. The M2 versions has improved GPU core scaling efficiency, but not quite enough to make a 144 GPU core model worthwhile, if the rumors of the Extreme model being canceled are true (I really hope not).

If the GPU scaling for the M1 Ultra was say 75% efficient, it would have scored about 125k in GB5 Metal. About the performance of a Radeon Pro 6800. An Extreme version with 128 GPU cores at 60% efficiency would be 200k in GB5 Metal. That's Nvidia 3080 territory, maybe even 3090. Both would have been suitable for a Mac Pro, but alas no. The devil is in the details. The Apple Silicon GPU team fucked up imo.

Hreb said:

The claim of "up to 76 cores" is interesting.  Currently the macos kernel has a hard limit to 64 cores.  Apple could obviously raise that, but I doubt they'd do that outside a major release of macos.  But macos 14 could certainly have a higher core thread limit.

commentzilla said:

If this is true what is the point of a bigger Mac Studio Pro? I don’t see a justification.