@Hammer

Quote:

I'm aware of slow MMUs that can impact users' use cases, but 68040 seems to be fast enough for HP-UX 9 and 24 MB RAM.

It depends 100% on the use case.

The 68040 has enough ATC to "control" 256 KB of memory.

* If your work load fits in this
= all good

* If your workload is bigger but you move very sequential through memory.
= all good.

* If the memory you use is more then 256 KB, and you not work sequential in it.
E.g. draw DOOM like
E.g. draw scroll bars on Workbench
E.g. Scan in memory database column
= BAD with unpredictable performance loss

@Gunnar

Quote:

Gunnar wrote: @Hammer Quote: I'm aware of slow MMUs that can impact users' use cases, but 68040 seems to be fast enough for HP-UX 9 and 24 MB RAM. It depends 100% on the use case. The 68040 has enough ATC to "control" 256 KB of memory. * If your work load fits in this = all good * If your workload is bigger but you move very sequential through memory. = all good. * If the memory you use is more then 256 KB, and you not work sequential in it. E.g. draw DOOM like E.g. draw scroll bars on Workbench E.g. Scan in memory database column = BAD with unpredictable performance loss

PC DOS Doom is a single-task deployment until Pentium era Windows 95's Doom 95 (DirectShow/Win32 port). Classic Amiga has "kicked the OS" games.

I have a Pentium 166-based PC for WinDoom and WinQuake on Windows 95 OSR2 (Aug 1996). The video card's 2D accelerator is a major factor.


i386 has the necessary instruction set which includes i386 MMU for 486 and Pentium improved upon.


WinDoom (leaked WinG/Win32S port for Windows 3.1/Win32S) will be slow on 386DX-40, but it will run. The same problem for 386DX-40 will be slow for Windows 95's Doom 95.

When there are "killer apps", software drives hardware sales e.g. PC DOS Quake (1996), WinQuake (Jan 1997), and GLQuake (Jan 1997).

Are you claiming 68060 rev 6 @ 100Mhz is substantially inferior to the classic Pentium 100 Mhz?

Many pro-68K advocates claim the 68060 CPU is a Pentium class CPU. The MC68060 contains independent instruction and data MMUs. Each MMU contains a cache memory called the address translation cache (ATC). ATC has 64 entries.

On X86 world, TLB caches are increased over time e.g.

386's Memory Management Unit (MMU) has a 32-entry (128 Byte) TLB (Translation Lookaside Buffer).

Pentium Pro has 64 entries for Data TLB at 4KB pages and 32 entries for instructions TLB at 4KB pages.

Intel's Nehalem has a 512-entry L2 TLB cache for 4 KB pages.

Newer IA-32 and X86-64 CPUs are fully backward compatible with the i386 including its MMU and the difference is in performance.

----
For NeXTStep retro, the problem is 68060's missing instructions from 68040 and the need for 68060SP.

68060SP included in Linux kernel sources. https://github.com/torvalds/linux/tree/master/arch/m68k/ifpsp060

Last edited by Hammer on 27-Feb-2024 at 03:59 AM.

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@Gunnar

Quote:

Gunnar wrote: @Hammer HAMMER THIS FORUM IS AMIGAWORLD Your post is not related to Amiga at all.

You marketed your AC68080 to be faster than the classic Pentium. You referred to the modern X86 CPU designs for your AC68080.

Look in the mirror.

For Amiga Hombre, Commodore selected PA-RISC. Don't mix up Motorola's 68K products with Commodore Amiga's custom chipset.

Like TheA500mini, AmigaKit's A600GS is at least ARMv8 CPU e.g. ARM Cortex A53 or higher. A-Eon's A1222Plus has PowerPC e500V2.

For most Amiga-related use cases, 68K is a virtual processor target across many AmigaOS-like platforms which rendered Amiga Inc (Bill McEwen era)/Tao Group's virtual processor redundant.

Last edited by Hammer on 27-Feb-2024 at 04:26 AM.
Last edited by Hammer on 27-Feb-2024 at 04:24 AM.
Last edited by Hammer on 27-Feb-2024 at 04:12 AM.
Last edited by Hammer on 27-Feb-2024 at 04:08 AM.

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@Hammer

Quote:

Are you claiming 68060 rev 6 @ 100Mhz is substantially inferior to the classic Pentium 100 Mhz?

No one said anything like this.


Why can't you just talk like a normal person using "words"
about an Amiga topic without cut and pasting tons of sentences from Wikipedia?

@Hammer

Quote:

Hammer wrote: On X86 world, TLB caches are increased over time e.g. 386's Memory Management Unit (MMU) has a 32-entry (128 Byte) TLB (Translation Lookaside Buffer). Pentium Pro has 64 entries for Data TLB at 4KB pages and 32 entries for instructions TLB at 4KB pages. Intel's Nehalem has a 512-entry L2 TLB cache for 4 KB pages.

Why are you reporting the data for the L2 TLB cache? Those are very different from the L1 TLB caches! They are also important to mitigate the penalty for avoiding as much as possible to access the memory for traveling the page hierarchy, but... they require more cycles for this compared to the L1 TLB caches.

This clarified, the L1 caches TLBs did not increase so much on x86 processors, besides for the code cache. But, even there, they are usually around 128 (and 64 for the data cache) for 4kB pages.

The good thing is that there are TLBs also for large pages, but their number is usually inferior compared to the 4kB ones.

@HAMMER

Quote:

For NeXTStep retro, the problem is 68060's missing instructions from 68040 and the need for 68060SP. 68060SP included in Linux kernel sources. https://github.com/torvalds/linux/tree/master/arch/m68k/ifpsp060

Yes the Motorola 68060 CPU misses a number of instructions. We are all aware of this.
But why do you post this now? Where is the relation to the topic?

When you mention that the 68060 suffers from missing instructions.
Why do you talk about NEXTSTEP?
We are in an Amiga forum here. No one cares about Next.
Why dont you talk about the Amiga programs that have problems with the 68060 missing instructions?
Or why dont you talk about the number of games like SpeedBall that crash because of this.


Talking with is very hard as your posts look like a bouncing flipper ball -
it looks like you are unable to focus on any topic.

You post look always like a random collection of googles sentences -
often with very little or no relation to the main topic.

This makes you look like a broken bot, or someone who is not able to understand what the topic was.

Why do you post so strange?
Do you think you could stop this and talk about a topic like a normal human being?

Last edited by Gunnar on 27-Feb-2024 at 06:35 AM.

@Gunnar

Well, I care about NeXT... quite a lot of Amiga software was heavily inspired by NeXTSTEP - MagicWB, MUI, ToolManager and other "dock" variants, MagicMenus and lots more. The initial OS4 "mock ups", long before Hyperion, were also very much inspired of what NeXTSTEP was doing already.

I used to have a NeXTStation in my office at univ, before I sent it to computer museum that never materialised. For a while it was dual-booting NeXTSTEP 2.1 and Plan9, (being a node in a cross-arch Plan9 cluster), but I think I got hold of and installed NeXTSTEP 3.2 or so before it vanished for me.

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