Age of Empires 2: Definitive Edition consistently de-syncs when playing across a M1 Mac (using Windows 11 Arm or Crossover) and an x86 machine, and I suspect the difference in floating point behavior described here is the culprit: https://developer.apple.com/documentation/apple-silicon/addr...
LHC@Home had big issues[1] with AMD and Intel machines giving very different results to the same work unit. They traced it down to the exp() function behaving different, and ended up using a library[2] for anything more fancy than basic arithmetic.
Another reason for me to stay clear of the M1 for now. It’s really fascinating, but it’s not quite there yet. I’ll let others work the rough edges away before I give it a try.
Adding onto this, this article compares various approaches to getting money “early” out of a 401k/tIRA (Roth conversion ladder as said here, 72t SEPP’s, early withdrawal penalty), and has the surprising conclusion that even the “just pay the 10% penalty” comes out ahead of regular taxable contributions, at least in some situations.
iPad mini 4 is A8 with 2GB of RAM and remains supported. iPad Air 2 is A8X (with 2GB of RAM) too and remains supported. Other devices to remain supported are Apple TV HD (A8 with 2GB of RAM) and HomePod (A8 + 1GB RAM, but no big UI to deal with).
Unsupported A8 devices:
iPod Touch 6, iPhone 6/6 Plus, both because of RAM size
While the readme does state this (could be) a joke, this unfortunately isn't possible with PCI-e today:
Motherboards only support directly accessing a (up to) 256 MB segment of VRAM directly from the CPU. This is the BAR1 space/aperture space.
So attempts to create allocations larger than that that are resident in VRAM but also accessible from the CPU will land in system memory, in order to ensure they are accessible from the CPU. Graphics drivers will either have the GPU read the data from system memory, or will do hidden copies to the GPU when they detect the resource is bound, etc.
The author sort of suspects this could be happening:
"There is no guarantee that the persistently mapped buffer technique actually references video memory. The worst case it's shadow memory and this actually wastes memory."
This sounds like a little bit of confusion. Its the PCIe aperture your referring to, and its size/location is dependent on the machine/bios in use as much as the requested BAR sizes. A lot of recent xeon and workstation level machines actually again support 64-bit PCI aperture windows. See the discussion about which machines are compatible with the xeon phi which requires 8GB (or more) of MMIO space.
Bottom line, most desktop machines only use a legacy 32-bit PCIe window below 4GB. That is why its limited to a fairly small amount of address space (256-1G generally). The ugly problem is that without purchasing a product its generally quite difficult to determine if it supports a 64-bit aperture correctly. Take the Asus x99A board I have, no mention of support one way or the other, but with an i7 (not just a xeon) it actually works with the xeon phi.
(BTW: Nvidia did a better job with this, their tesla cards have a GPU compatibility mode where they restrict the BAR to 256MB for machines that don't support 8GB BARs).
