Inside the PowerPC 970

daveschroeder writes "Jon "Hannibal" Stokes has posted a long-awaited, very detailed analysis of the IBM PowerPC 970 at Ars Technica. Notable quote: 'The 970 was made for Apple'."

Comments

deja vu

[groundpig]

Its like comparing apples with apples... Its a dupe.

Dupe?

[krisp]

It's ok, the last post didn't get enough comments. Please continue discussion.

In the market for a 64-bit workstation?

[idiotnot]

Fast forward a few months....hmm...a few options:

Sun: Nice hardware, very expensive, CDE.
AMD: Commodity hardware, cheap, WinXP.
HP: Intel hardware, very expensive, CDE or WinXP.
I think I know what I'd buy.

Of course, the Athlon64/Opteron would get quite a bit of consideration due to my hobbies.

But I think it'd end up being the Mac.

Re:In the market for a 64-bit workstation?

[Mooncaller]

I did not have much trouble getting GNOME working on a HP B180 with HP-UX 10.20 ( compiled with acc, HP-UXs standard compiler). BTW that is a 180MHz PA-RISC machine. It kicked a 1GHz Pentium based workstations butt, even after I put Gentoo on the Intel box ( it original had only Windows NT, shudder). Fast clock rates can't compensate for a moronic architecture in the hands of heavily multitasking users like me.

Re:What the heck is 'Altivec' anyway?

[binaryDigit]

Floating point ops, optimized for graphics processing and things like compression (jpeg, mpeg, mp3). If you read the Ars article he waxes on about it's superiority over MMX/SSE/SSE2.

Isn't it obvious...

[GrodinTierce]

I believe that Hannibal mentions that the 970 is designed for SMP.. Clearly CmdrTaco is just testing its newest feature: you click post and the operation gets carried out by both processors.

Tierce

Re:drop AltiVec

[Wyatt Earp]

AltiVec is nice for somethings.

My iTunes ripping of mp3s nearly tripled when I went from a 466 MHz G3 to a 400 MHz G4 due to iTunes being optimized for AltiVec.

Some Photoshop actions and filters see up to 800% improvments.

Running iMovie exports on a 600 MHz G3 iMac take 2-300% longer than on a 400 or 500 MHz G4

Re:drop AltiVec

[Textbook Error]

AltiVec is important for Apple marketing because it lets them claim impressive performance figures without actually needing to push the state of the art in terms of processor design further than Intel.

No, AltiVec is important for Apple full stop - in the short term to make up for the anemic bus speeds allowed by the G4, and in the longer term because a SIMD unit is now as expected a component of modern desktop CPUs as an FPU is.

And even something like a hand-coded vectorized BLAS library doesn't help because most scientific software still doesn't use such libraries

The only thing you can really sure about "most" scientific software is that it needs an FPU. Scientists and engineers do a huge variety of simulations, some of which are vectorizable and some of which aren't.

If AltiVec has a weakness in the scientific field, it's the lack of support for double precision. And there's nothing in the instruction set which precludes this, so I wouldn't be surprised to see it appear in some future CPU.

Imagine how much better it would be if Apple could ship systems based on the 970 today, rather than after a few months additional delay due to AltiVec.

If it didn't have AltiVec, it wouldn't be what Apple needs in a desktop CPU - not much point in getting what you don't need a few months early (not like that would happen anyway: this isn't lego: you can't unplug "the AltiVec bits" without any impact on the rest of the design).

And every dollar and watt that is shaved off the AltiVec price makes it a much more viable processor for servers and blades, which would get volume up and prices down.

Except that Apple aren't currently in the blade market at all, and have a fairly small presence in the more general server market. If they can sell a few boxes there, fine, but getting the volume up means targetting consumers - not server farms.