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Intel Itanium IA-64 Support Removed with the Linux 6.7 Kernel

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Re: Intel Itanium IA-64 Support Removed with the Linux 6.7 Kernel

#151

Post by p_l »

the_panopticon wrote: post #26

As necessity is the mother of invention, Itanium did lead to UEFI, though The Chicken and the Egg The very first effort that is considered a direct ancestor of UEFI technology had a very specific tactical goal. In the course of 1997 people at Intel were working on how to boot computers based on the prospective Itanium® Processor family...." from https://www.intel.com/content/dam/www/public/us/en/documents...

Very early the project incorporated x86, because Intel planned on keeping x86 in the play for quite a long time.

For a time, you could easily download a devkit for EFI on x86 which included tools and source code for EFI 1.1.

Re: Intel Itanium IA-64 Support Removed with the Linux 6.7 Kernel

#152

Post by pjmlp »

p_l wrote: post #150
pjmlp wrote: post #134

Earlier quoted context omitted.

The lesson here is that AMD should not have been allowed access to Intel's IP, that is what allowed them in first place to undermine Intel's Itanium plans.

The license was a requirement for intel to get initial sales of x86 at all.

I am aware of it, little did they know what pain it would cause them.

Re: Intel Itanium IA-64 Support Removed with the Linux 6.7 Kernel

#153

Post by p_l »

anarazel wrote: post #107
vgatherps wrote: post #87

Earlier quoted context omitted.

It would probably be even worse today. Dynamically discovering ILP “just works” even as memory gets slower and slower and slower. A CPU today can execute hundreds of instructions and many predicted branches ahead of a slow load. It would be impossible to statically schedule this (you don’t know what will/won’t be in cache), and difficult to try and hoist all loads 100 instructions in advance especially when you take…

For GPUs it only really works because the code is translated to the relevant instruction steam close to the time of executing, where you can afford to optimize in a highly uarch specific way. Whereas VLIW at the time of itanium never was in that position... It just doesn't compute for me how Intel thought this was a good plan. It's not like they didn't know that existing compiled binaries are going to continue being…

The critical part was less VLIW, and more EPIC - the Explicit Parallel part. There were previous VLIW arches that didn't have issues with compilers, one of them afaik even formed backbone of many advanced optimizing compilers in 1990s because the vendor licensed the compiler tech to others.

Re: Intel Itanium IA-64 Support Removed with the Linux 6.7 Kernel

#154

Post by p_l »

pengaru wrote: post #124
failuser wrote: post #32

The worst thing about Itanium is that it killed DEC Alpha, high-performance MIPS and some other arches I keep forgetting about.

Jim Keller has stated in at least one talk that DEC went bankrupt after Windows NT on Alpha kept crashing because they'd designed the Alpha with weak memory ordering and MS wouldn't implement the necessary memory barriers. Didn't sound like Itanic played a part at all.

Itanic played part after Compaq buyout, where Compaq decided to bank all on Itanium sight unseen of actual usable parts, IIRC.

The end result was that they had to restart development of EV7 then restart its production again, because many, many ex-DEC customers didn't want to move to Itanium (customers running Tru64 mostly moved to Linux on amd64 or occasionally to other RISC vendors instead of dealing with HP-UX, whereas OpenVMS customers kept to Alphas which outperformed Itanium usually or moved off the platform completely, with stragglers now moving to amd64)

Re: Intel Itanium IA-64 Support Removed with the Linux 6.7 Kernel

#155

Post by p_l »

bombcar wrote: post #100
twoodfin wrote: post #46

Earlier quoted context omitted.

Data center computing being dominated by commodity Linux running on commodity x86 PC architecture—for which the best CPUs were not commodities, but rather made exclusively by Intel—was likely the best of all possible worlds for them! Going back to at least the i432, Intel seems to have had a deep vein of “mainframe envy” in their culture and strategic thinking. It seems that somehow the market (and a bit of trailblaz…

It was great for Intel - but it wasn't great for certain big manufacturers (dinosaurs) that they were courting. I think they knew they could fall back on x86 if everything went wrong - but what they did NOT expect was x86-64 to just smash everything. That caught them on backfoot.

I remember the public roadmaps in tech magazines at the time, and Intel planned on keeping "consumer" market 32bit for longer time - then AMD dropped the Hammer ;>

Re: Intel Itanium IA-64 Support Removed with the Linux 6.7 Kernel

#156

Post by p_l »

fulafel wrote: post #131
bitwize wrote: post #24

Earlier quoted context omitted.

Itanic was hype from the word go. Intel tried and failed twice to make "VLIW CPUs that rely on 'sufficiently smart' HLL compilers doing the right instruction packings" a thing before Itanium came along (iAPX 432 and i860). I think someone very high up at Intel was in love with the idea despite its repeated failures. Alpha was clearly the future -- and Itanic ruined Alpha. We didn't even get to see it live on inside s…

I hadn't heard about compiler vs 432 before, any links?

I do recall some discussion about combination of really bad code generation combined with some ridiculously bad design decisions (I think it might have been total lack of cache?)

Re: Intel Itanium IA-64 Support Removed with the Linux 6.7 Kernel

#157

Post by p_l »

dvaletin wrote: post #18

Why it took so long?

It took extra long because for various reasons it was the officially blessed architecture (specifically, HP-UX on Itanium) for running Oracle databases, leading to HP suing Oracle when the latter bought Sun and essentially declared HP-UX is to soon be EOL'd

Re: Intel Itanium IA-64 Support Removed with the Linux 6.7 Kernel

#158

Post by Symmetry »

IAmLiterallyAB wrote: post #93

I really like the idea of VLIW CPUs, it's a shame none of them have worked out. Does anyone know of any other cool more modern CPU designs? Stuff like RISCV is fine but doesn't feel particularly innovative

The Hexagon DSPs in Qualcomm's Snapdragon SoC line are VLIWs. Also, NVidia used some cores from the Transmeta lineage in some of its mobile SoCs for application cores. There was a program that ran on them that automatically rewrote ARM instructions to their own ISA that not only was VLIW but was a skewed pipeline VLIW! That's what the Mill guys call phasing, see here: https://millcomputing.com/wiki/Phasing

Re: Intel Itanium IA-64 Support Removed with the Linux 6.7 Kernel

#159

Post by Symmetry »

quux wrote: post #97
IAmLiterallyAB wrote: post #93

I really like the idea of VLIW CPUs, it's a shame none of them have worked out. Does anyone know of any other cool more modern CPU designs? Stuff like RISCV is fine but doesn't feel particularly innovative

The mill architecture has interesting ideas but as far as I know it’s never made it past simulation and there hasn’t been much progress lately. https://millcomputing.com/

They had a bunch of really interesting ideas but trying to innovate in more ways at once brings exponentially more risk. And there weren't only trying to reconceptialize how computers worked, they also were doing a weird innovative corporate structure too.

Once the patents expire I hope someone makes a RISC-V design that just tries to get their, e.g., virtual and backless memory working with Linux. That seems like it would be worthwhile in and of itself.

Re: Intel Itanium IA-64 Support Removed with the Linux 6.7 Kernel

#160

Post by ethbr1 »

arcticbull wrote: post #92
ethbr1 wrote: post #63

Earlier quoted context omitted.

I've still got a 2.8 GHz Pentium 4 Northwood squirreled away somewhere. The machine it originally ran in is humming away too, albeit with a replacement Pentium M using a socket 478 adapter. I keep it as a reminder that even billions of dollars can't see around the future corner.

Fun fact: the Pentium M you put in is the actual predecessor to modern Core processors - not the Pentium 4 you took out of the socket. The NetBurst microarchitecture of Pentium 4 was killed off and a 64-bit version of the P6 Variant Enhanced Pentium M microarchitecture took the baton.

That's why I bought it! By that point, Core had already been released, and I figured "What a weird historical quirk to keep around."
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