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MIPS Technologies Porting Android 4.1 to MIPS Architecture
angry tapir writes with news on Android getting support for a third architecture. From the article: "ARM rival MIPS is continuing its push to make a mark in low-cost tablets and quickly trying to bring Android 4.1 (Jellybean) to its processors. 'We are working aggressively on bringing Jelly Bean to MIPS, and expect that it will be available to our licensees very soon,' said Jen Bernier-Santarini, director of corporation communications at MIPS, in an email. Tablets with MIPS processors are largely low-cost and have found buyers mostly in developing countries. MIPS last week said a new tablet called Miumiu W1 from Chinese company Ramos would become available in a few months in India, Latin America and Europe. The tablet has a 7-inch screen, a MIPS processor running at 1GHz, front camera and a microSD slot for expandable storage."
Good, finally ARM manufacturers will stop having a monopoly where they can charge whatever they want. I've seen hints at OEM chip prices and they're ridiculous compared to even desktop chips. That will help everyone...just in time for x86 tablets to come out so people can actually run whatever they want.
By the way, if you're wondering as I did but were too lazy to look it up, yes, they actually named themselves MIPS without noticing that that's also Millions of Instructions Per Second, a method for measuring the speed of any CPU. Theirs stands for Microprocessor without Interlocked Pipeline Stages and it refers to an instruction set. What an unfortunate oversight. Stages could have been replaced with just about any other word to differentiate it.
It doesn't matter really. ARM uses some 0.1-1.0W, MIPS uses 10-20W for slower clock speeds. ARM has fixed-width single-decode instructions; MIPS has three types of instructions of variable width. ARM does damn near everything in one clock, including evaluate-and-execute prefixed instructions ( { if ( n ) m = 5; } is 2 insns: 'cmp n' and a prefixed 'movnz m, 5'. If n == 0, movnz means 'nop'; otherwise it means 'mov'. Instead of 'cmp n; jnz @@a; mov m,5; @@a:' where jnz and mov have to be evaluated in separate stages. Yes it's been 11 years since I did assembly, it was 286 and 6502, and I'm unfamiliar with ARM by far). MIPS is slow. You may as well put an Intel CELERON in there if you go MIPS.
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Wikipedia is your friend. Apparently, like an unwanted child, the company got passed around a few times, being bought by SGI, only to be spun out again. It's easy to speculate how an engineer working for an unstable company like that would have other things in mind besides designing the fastest and greatest processors.
ARM uses some 0.1-1.0W, MIPS uses 10-20W for slower clock speeds.
Not anymore, by far. Forget about MIPS as in Silicon Graphics workstations ages ago. Now MIPS is an embedded IP provider, very similar to ARM. And they do have low power cores quite similar to ARM. Who is on top in mW/MHz changes over time, but MIPS do have some competitive offers.
Now what ARM has for it is that it became the defacto architecture for mobile (nobody got fired to chose ARM and all that), and it has much more resources than MIPS. So ARM has a more extensive IP offer, and can work on process optimization too. By this I mean that where MIPS will provide a soft core in RTL, ARM can also provide hard macros optimized for some fab process. And even if you want to go soft core and optimize yourself, ARM can provide a ready to use optimization package to get you started.
ARM has fixed-width single-decode instructions; MIPS has three types of instructions of variable width.
No, they're actually very similar: their native instruction size is 32 bits, but both support a 16 bits instruction mode which is in its second generation in each case (Thumb2 for ARM, can't remember the MIPS name... Maybe MIPSe?).
MIPS is slow. You may as well put an Intel CELERON in there if you go MIPS.
Why the comparison with a discrete chip? MIPS do no sell discrete chips anymore, it's all IP. Then in IP they have offer that are performance competitive with the same class ARM. I'd give the edge in the high end to ARM though, thanks to their close work with the fab to optimize their implementation.
I'm not sure that MIPS is so well placed in the high-end. Yes, they've been high end a long time ago and have had 64 bits support for ages. But today it's a different game, they provide embedded IP now. And where ARM can help their customers optimizing the implementation for a given process (ARM gains this experience by making hard macros and working closely with TSMC, GlobalFoundries...), MIPS has much less resource and just do soft macros. Then up to you to do the optimization. In other words, if you go ARM for an embedded high-performance SoC IP you can leverage a lot of work that ARM does, that you will have to do with MIPS. To get an implementation that is less common in the end.
So the high end may be tough for MIPS. But in the medium end, where price is critical and performance less so, they can be an interesting choice.