Que?

There must be more to it than this. The article just makes is sound like they've just put an MMU on it. Hardly masses of silicon required there.

If thats the case, than this is less of a triumphant announcement and more of about b*ddy time.

64bit indeed required

I am a server programmer in the financial industry and I know many applications need 64bit addressing, as the process sizes are already well above 4Gb. Yes, single processes with 7Gbyte memory consumption are used quite often in very central places.

Some applications could be split up on more parallel process instances, but some applications like OLAP need as much RAM as they can get. All the legacy software needs as much memory as possible and they are already well in the post-4Gb range. Modern applications are desgined to be spread over many process instances and physical machines, so maybe they can deal with the 4GB limit. But things like CAE and CAD also need as much memory they can possibly get to design a new CPU or something like the Airbus A400M or the Boeing 787.

ARM better come up with a clean solution to address at least 1000GByte of process memory with simple C/C++ pointers. Whether it must be full 64bit pointers I don't know. Maybe they can devise something that needs less storage. After all, current 64bit pointers carry at least 3 byte of redundant data EACH.

Future disappointment

I remember the launch of Windows NT. The Hardware Abstraction Layer - yeilding the choice of PowerPC or Intel. It never worked.

So, while I wish for:

"it will be much more fun for the rest of us if ARM becomes a credible alternative to the x64 architecture for servers, netbooks, and maybe even other PCs at some point. Stranger things have happened."

... I fear there there will never be real choice unless masses away from Windows to Linux / Android.

Gak

Didn't we finally get all that address-obstuficating-workaround-hack clutter *out* of the x86 arch? I'd prefer something very ARM-like but with a re-structured instruction set around a 48-bit flat address space. Or an x86-64 with all legacy instruction/addressing modes stripped might be interesting.

"I remember the launch of Windows NT"

Best TPM article for yonks. Best of luck to ARM. But they've got an uphill battle on their hands, and not just at a technical level.

"I remember the launch of Windows NT"

But maybe you don't remember it very well.

"The Hardware Abstraction Layer - yeilding the choice of PowerPC or Intel. It never worked."

It may never have worked on your PowerPCs, I don't know.

In the rest of the world, it was also supposed to work on any conforming box from the Advanced RISC Computing consortium, whose members used not just PPC but MIPS and Alpha.

The HAL concept worked fine on the NT/Alpha boxes I used, from Multia to AlphaStation 400 to DIGITAL Personal Workstation PWS500a and indeed various DIGITAL Server boxes. I probably still have the relevant MSDN CDs somewhere, paid for by my (not my employer's) money.

At least, it worked as far as Gates allowed it to, and as far as the pre-virtualisation miracle that was FX!32 allowed it to. FX!32 was DEC software for NT/Alpha that allowed on-the-fly translation (not emulation) of x86/Win32 apps to Alpha/Win32 apps, as had been pioneered earlier by their VAX to Alpha translators.

Other ARC players didn't have equivalents of FX!32 so they were even more reliant on recompiled-to-native versions of Windows apps, which of course Gates never really provided except for x86.

Then after a little while Gates said to DEC: "You can either be Larry's friend or you can be my friend" and DEC's top folks didn't choose Bill. The rest is history.

Speaking of history, now that the history of massive anti-competitive backhanders and/or commercial blackmail (call it what you will) over many years between intel and Dell is finally emerging into daylight, it would be interesting to know what kind of sweetheart deals went on between Intel and Microsoft so that Intel didn't have to face any real competition in the chip market. I know from personal experience that Intel were quite happy to twist people's arms if they were threatening to look at AMD in any significant way.

Fortunately that kind of rubbish doesn't (can't) go on in the open source market.

"even on x86-64, the full address space isn't implemented"

Lou, don't forget there's a difference between what a chip architecture supports in principle, and the subsets which may be implemented in any particular implementation of an architecture. x86 isn't an architecture, it's a collection of engineering kludges with an extensive set of supporting software.

PDP11s were nominally a 16bit architecture but you could have 4MB of memory on some of them, so more physical address space than logical address space is not exactly new to the world. The magick lies in doing it cleanly so that transitions between different implementations don't cause nightmares (eg if "clever" people have found creative uses for "unused" address bits, e.g. "to save space").

AMD64 seems reasonably clean in this respect (it's not really x86-64 is it, whatever Intel would prefer).

It's heartening to know that Britain actually makes something ...

along with Cornish Pasties and Peas Pottage since they no longer have domestic manufacturing as they once did in Morris, Leyland, Plessey, Marconi, etc. Even screw, nuts and bolts are imported.

Even my Wellington Boots have 'Made in China' on them, as do 'Saville Row' suits (most are made in ShangHai nowadays).

Let's hope some some overseas conglomerate doesn't buy up ARM Holdings and that it continues with it's technological prowess. A British winner.

Good old days are back...

Hehe, sounds like the BBC 128K model all over again. ;-)

Nice one ARM.

@boltar re "confused about what "bits" means wrt CPUs "

"When a CPU is called 64 bit that number is generally referring to the size of the data registers, not the size of the address or data bus."

So, what's a 64bit OS then, in this context?

You might find that a convenient definition might be something that supports a nominal 64bit address space (perhaps not fully implemented yet) on a 64bit-addressable CPU.

You can have 32bit registers in a 16bit chip, and vice versa.

Care is indeed needed to avoid confusion.