That’s no less true than games written in C, or otherwise with few dependencies. Doom is way more portable than RCT precisely because it’s written in C instead of assembly.

I’m more familiar with RISC-V than I am with ARM though it’s my understanding they’re quite similar.

• ARM/RISC-V are load-store architectures, meaning they divide instructions between loading/storing and doing computation. x86 on the other hand is a register-memory architecture, having instructions that do both computation as well as loading/storing.

• ARM/RISC-V also have weaker guarantees as to memory ordering allowing for less synchronization between cores, however RISC-V has an extension to enforce the same guarantees as x86 and Apple’s M-series CPU have a similar extension for ARM. If you want to emulate x86 applications on ARM/RISC-V these kinds of extensions are essential for performance.

• ARM/RISC-V instructions are variable width but only in a limited sense. They have “compressed instructions” - 2 bytes instead of 4 - to increase instruction density in order to compete with x86’s true variable width instructions. They’re fairly close in instruction density, though compressed instructions are annoying for compilers to handle due to instruction alignment. 4 byte instructions must be aligned to 4 bytes, so if you have 3 instructions A, B and C but only B has a compressed version then you can’t actually use it because there must be 4 bytes between instructions A and C.

• ARM/RISC-V also makes backwards compatibility entirely optional, Apple’s M-series don’t implement 32-bit mode for instance, whereas x86-64 still has “real mode” for running 16 bit operating systems.

There’s also a number of other differences, like the number of registers, page table formats, operating modes, etc, but those are the more fundamental ones I can think of.

Up until your post I had thought it exactly was the size of the instruction set with x86 having lots of very specific multi-step-in-a-single instruction as well as crufty instruction for backwards compatibility (like MPSADBW).

The MPSADBW thing likely comes from the hackaday article on why “x86 needs to die”. The kinda funny thing about that is MPSADBW is actually a really important instruction for (apparently) video decoding; ARM even has a similar instruction called SABD.

x86 does have a large number of instructions (even more so if you want to count the variants of each), but ARM does not have a small number of instructions and a lot of that instruction complexity stops at the decoder. There’s a whole lot more to a CPU than the decoder.

compressed instruction set /= variable-width […]

Oh for sure, but before the days of super-scalars I don’t think the people pushing RISC would have agreed with you. Non-fixed instruction width is prototypically CISC.

For simpler cores it very much does matter, and “simpler core” here can also could mean barely superscalar, but with insane vector width, like one of 1024 GPU cores consisting mostly of APUs, no fancy branch prediction silicon, supporting enough hardware threads to hide latency and keep those APUs saturated. (Yes the RISC-V vector extension has opcodes for gather/scatter in case you’re wondering).

If you can simplify the instruction decoding that’s always a benefit - moreso the more cores you have.

Then, last but not least: RISC-V absolutely deserves the name it has because the whole thing started out at Berkeley.

You’ll get no disagreement from me on that. Maybe you misunderstood what I meant by “CISC-V would be just as exciting”? I meant that if there was a popular, well designed, open source CISC architecture that was looking to be the eventual future of computing instead of RISC-V then that would be just as exciting as RISC-V is now.

The original debate from the 80s that defined what RISC and CISC mean has already been settled and neither of those categories really apply anymore. Today all high performance CPUs are superscalar, use microcode, reorder instructions, have variable width instructions, vector instructions, etc. These are exactly the bits of complexity RISC was supposed to avoid in order to achieve higher clock speeds and therefore better performance. The microcode used in modern CPUs is very RISC like, and the instruction sets of ARM64/RISC-V and their extensions would have likely been called CISC in the 80s. All that to say the whole RISC vs CISC thing doesn’t really apply anymore and neither does it explain any differences between x86 and ARM. There are differences and they do matter, but by an large it’s not due to RISC vs CISC.

As for an example: if we compare the M1 and the 7840u (similar CPUs on a similar process node, one arm64 the other AMD64), the 7840u beats the M1 in performance per watt and outright performance. See https://www.cpu-monkey.com/en/compare_cpu-amd_ryzen_7_7840u-vs-apple_m1. Though the M1 has substantially better battery life than any 7840u laptop, which very clearly has nothing to do with performance per watt but rather design elements adjacent to the CPU.

In conclusion the major benefit of ARM and RISC-V really has very little to do with the ISA itself, but their more open nature allows manufacturers to build products that AMD and Intel can’t or don’t. CISC-V would be just as exciting.

Wrong. Unified memory (UMA) is not an Apple marketing term, it’s a description of a computer architecture that has been in use since at least the 1970’s. For example, game consoles have always used UMA.

Apologies, my google-fu seems to have failed me. Search results are filled with only apple-related results, but I was now able to find stuff from well before. Though nothing older than the 1990s.

While iGPUs have existed for PCs for a long time, they did not use a unified memory architecture.

Do you have an example, because every single one I look up has at least optional UMA support. The reserved RAM was a thing but it wasn’t the entire memory of the GPU instead being reserved for the framebuffer. AFAIK iGPUs have always shared memory like they do today.

It has everything to do with soldering the RAM. One of the reason iGPUs sucked, other than not using UMA, is that GPUs performance is almost limited by memory bandwidth. Compared to VRAM, standard system RAM has much, much less bandwidth causing iGPUs to be slow.

I don’t disagree, I think we were talking past each other here.

LPCAMM is a very recent innovation. Engineering samples weren’t available until late last year and the first products will only hit the market later this year. Maybe this will allow for Macs with user-upgradable RAM in the future.

Here’s a link to buy some from Dell: https://www.dell.com/en-us/shop/dell-camm-memory-upgrade-128-gb-ddr5-3600-mt-s-not-interchangeable-with-sodimm/apd/370-ahfr/memory. Here’s the laptop it ships in: https://www.dell.com/en-au/shop/workstations/precision-7670-workstation/spd/precision-16-7670-laptop. Available since late 2022.

What use is high bandwidth memory if it’s a discrete memory pool with only a super slow PCIe bus to access it?

Discrete VRAM is only really useful for gaming, where you can upload all the assets to VRAM in advance and data practically only flows from CPU to GPU and very little in the opposite direction. Games don’t matter to the majority of users. GPGPU is much more interesting to the general public.

gestures broadly at every current use of dedicated GPUs. Most of the newfangled AI stuff runs on Nvidia DGX servers, which use dedicated GPUs. Games are a big enough industry for dGPUs to exist in the first place.

“unified memory” is an Apple marketing term for what everyone’s been doing for well over a decade. Every single integrated GPU in existence shares memory between the CPU and GPU; that’s how they work. It has nothing to do with soldering the RAM.

You’re right about the bandwidth though, current socketed RAM standards have severe bandwidth limitations which directly limit the performance of integrated GPUs. This again has little to do with being socketed though: LPCAMM supports up to 9.6GT/s, considerably faster than what ships with the latest macs.

This is why user-replaceable RAM and discrete GPUs are going to die out. The overhead and latency of copying all that data back and forth over the relatively slow PCIe bus is just not worth it.

The only way discrete GPUs can possibly be outcompeted is if DDR starts competing with GDDR and/or HBM in terms of bandwidth, and there’s zero indication of that ever happening. Apple needs to puts a whole 128GB of LPDDR in their system to be comparable (in bandwidth) to literally 10 year old dedicated GPUs - the 780ti had over 300GB/s of memory bandwidth with a measly 3GB of capacity. DDR is simply not a good choice GPUs.

Distributed ledger data is typically spread across multiple nodes (computational devices) on a P2P network, where each replicates and saves an identical copy of the ledger data and updates itself independently of other nodes. The primary advantage of this distributed processing pattern is the lack of a central authority, which would constitute a single point of failure. When a ledger update transaction is broadcast to the P2P network, each distributed node processes a new update transaction independently, and then collectively all working nodes use a consensus algorithm to determine the correct copy of the updated ledger. Once a consensus has been determined, all the other nodes update themselves with the latest, correct copy of the updated ledger.

From your first link. This does not describe how git functions. Did you actually read the page?

The consensus problem requires agreement among a number of processes (or agents) for a single data value. Some of the processes (agents) may fail or be unreliable in other ways, so consensus protocols must be fault tolerant or resilient. The processes must somehow put forth their candidate values, communicate with one another, and agree on a single consensus value.

From your second this. Again this description does not match with git.

You’re right in that automation is not technically required; you can build a blockchain using git by having people perform the distribution and consensus algorithms themselves. Obviously that doesn’t make git itself a blockchain in the same way it doesn’t make IP a blockchain.

Key word distributed ledger. Git repositories don’t talk to each other except when told to do so by users.

I shouldn’t need to explain why an access key is not a consensus algorithm. Seriously?

Well, I’m saying Circulor is most likely lying about their “blockchain” actually being a blockchain, or that they’ve pointlessly set up extra nodes to perform redundant work in order to avoid technically lying.

Blockchain is completely pointless without 3rd parties being part of the network. It’s like me saying I run a personal social network for just myself.

Git is not a blockchain. There is no distributed ledger; no consensus algorithm.

Polestar uses contracts and audits to ethically source materials, not blockchain. It uses blockchain as a shitty append-only SQL database to (apparently) tell you where the materials came from. Let me quote from Circulor’s website:

data can be fed seamlessly to the blockchain via system integration using RESTful Web Service APIs with security and authentication protocols

So the chain is private and accessible only through a centralized, authenticated REST API. This is a traditional web application. A centralized append-only ledger is not even a blockchain.

There’s a decent chance that’s still the salt lamp.

TLDs are valid in emails, as are IP V6 addresses, so checking for a . is technically not correct. For example a@b and a@[IPv6:2001:db8::1] are both valid email addresses.

So you push digital goods to a robust public platform like IPFS and tie decryption to a signed, non-revokable, rights token that you own on a block chain.

What you describe is fundamentally impossible. In order to decrypt something you need a decryption key. Put that on the blockchain and anyone can decrypt it.

Even if you can, pirates would only need to buy a single decryption key and suddenly your movie might as well be freely available to download. Pirates never pay hosting fees because it’s using the same infrastructure as customers and they can’t be taken down because they’re indistinguishable from customers.

Adding blockchain into the mix changes nothing. Whether your digital ownership is stored in their centralized database or a distributed database, they still have control over everything because they’re the ones streaming it to you. They can just as well block your access & block resale.

The only way to actually digitally own something is to have a full DRM-free copy of it (ianal though this still might not be enough to allow resale).

Oh I’m sure they can justify spending the time porting the game. I just can’t blame them for not doing so when Apple’s policy is to not give a shit.

Yes, but it’s highly unlikely they can reuse that effort. TF2 uses an older version of source, so you either end up having to update everything to a newer version or redo all the effort you’ve already put in to porting source, but for an older version. Now multiply that by the number of source games.

I can see how you might come to that conclusion, but porting to 64bit is way more involved than it may seem. x86-64 is different enough to x86 that you’re basically porting to a new architecture: all your assembly will break just like it would porting to arm. On top of that all your sizes have changed and caused all sorts of bugs, for instance: long is 4 bytes under 32 bit on all platforms, but it’s 8 bytes on macOS & Linux and 4 bytes on Windows under 64 bit.

It’s mind boggling that Apple would drop 32bit support. Adding 64 bit support can be a lot of effort, especially on older code bases, and there’s a whole bunch of games that’ll never receive updates again. You could’ve had arm32 support, with the ability to run any x86 games.

You say that like Apple would have to put in a ton of work for that. Android can already run on iPhones. It’s just an ARM computer. Project Sandcastle already exists. All they have to do is allow unlocking the bootloader just like they do on macs.