Linked by Thom Holwerda on Mon 31st Mar 2014 21:35 UTC
Apple

AnandTech on Apple's A7 processor:

I suspect Apple has more tricks up its sleeve than that however. Swift and Cyclone were two tocks in a row by Intel's definition, a third in 3 years would be unusual but not impossible (Intel sort of committed to doing the same with Saltwell/Silvermont/Airmont in 2012 - 2014).

Looking at Cyclone makes one thing very clear: the rest of the players in the ultra mobile CPU space didn't aim high enough. I wonder what happens next round.

This is one area where Apple really took everyone by surprise recently. When people talk about Apple losing its taste for disruption, they usually disregard the things they do not understand - such as hardcore processor design.

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RE: Comment by Drumhellar
by mutantsushi on Tue 1st Apr 2014 08:32 UTC in reply to "Comment by Drumhellar"
mutantsushi
Member since:
2006-08-18

I always wondered why a 32 bit variant of x64 wasn't released with the same register advances, but without 64 bit capability. Perhaps that was benevolent forward thinking in case of x86, although it's hard to see a usecase for that in mobile. Ultimately I don't think that aspect really matters one way or another.

It's kind of sad that 64bit is seen as an Apple innovation though, that's just ARM's latest standard design. The innovation in the CPU has to deal with other details besides that aspect.

Edited 2014-04-01 08:43 UTC

Reply Parent Score: 3

RE[2]: Comment by Drumhellar
by viton on Tue 1st Apr 2014 12:21 in reply to "RE: Comment by Drumhellar"
viton Member since:
2005-08-09

that's just ARM's latest standard design

ARM achitecture is a description of registers, instructions and memory model. You can download architecture manual freely from ARM site.
32bit ARM architecture was created by Roger Wilson back in the 80s.

That Apple did in A7 is totally amazing. Even X-Gene (first 64-bit ARM processor on paper) is not ambitious enough. A7 is wider than latest Intel processors and has comparable internal resources like 192-entry ROB, massive buffers, also memory bandwidth is good (The problem of most ARM application processors).

Edited 2014-04-01 12:23 UTC

Reply Parent Score: 4

RE[2]: Comment by Drumhellar
by Carewolf on Tue 1st Apr 2014 15:04 in reply to "RE: Comment by Drumhellar"
Carewolf Member since:
2005-09-08

That is called x32 (or x86 ILP32).

Reply Parent Score: 3

Drumhellar Member since:
2005-07-12

I think he's talking about a 32-bit processor with the other AMD64 features.

But, the lack of interest in Linux's x32 shows why it would've been a waste of resources to design a chip.

Reply Parent Score: 3

RE[2]: Comment by Drumhellar
by Drumhellar on Tue 1st Apr 2014 17:02 in reply to "RE: Comment by Drumhellar"
Drumhellar Member since:
2005-07-12

I always wondered why a 32 bit variant of x64 wasn't released with the same register advances, but without 64 bit capability. Perhaps that was benevolent forward thinking in case of x86, although it's hard to see a usecase for that in mobile. Ultimately I don't think that aspect really matters one way or another.


Well, the instruction format would have to be changed to accommodate extra registers - the x86 instruction format uses 3 bits to encode either source or destination register, which isn't to select from additional registers.

To make a 32-bit chip with the other architectural enhancements of 64-bit, you'd still have to enter a different processor mode - say, x86+, to execute software that takes advantage of the extra registers and flat x876/sse register file (x86 uses a stack), and executing older 32-bit code would still require a mode change.

IIRC, adding AMD64 capability to the Pentium 4 (Well, technically Intel-64, the purposely slightly incompatible knock-off) only increased the die space by ~5% anyways, and by the time x86 was being dropped into ultra-mobile designs, well, the 4GB address limitation was already looming close in those designs. A x86+ design would have probably only had one generation of use...

Reply Parent Score: 3