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ARM Unveils One-chip SMP Multiprocessor Core
An anonymous reader writes "ARM Ltd. will unveil a unique multi-processor core technology, capable of up to 4-way cache coherent symmetric multi-processing (SMP) running Linux, this week at the Embedded Processor Forum in San Jose, Calif.. The "synthesizable multiprocessor" core -- a first for ARM -- is the result of a partnership with NEC Electronics announced last October, and is based on ARM's ARMv6 architecture.
ARM says its new "MPCore" multiprocessor core can be configured to contain between one and four processors delivering up to 2600 Dhrystone MIPS of aggregate performance, based on clock rates between 335 and 550 MHz."
The MPCore multiprocessor enables system designers to view the core as a single "uniprocessor", simplifying development and reducing time-to-market, according to ARM.
The opposite of HyperThreading? 4 CPU's to one instead of 1 CPU to 2?
The only thing that I can guess they mean by simplifying is that a developer would not have to design a multi-threaded application to take advantage of the other threads.
In case you were wondering what that is all about...
Synthesis of a core is analagous to compiling your software- except in an FPGA it is processing a hardware definition language like VHDL or Verilog to create the 'code' used to load the FPGA.
This is a big plus for people wanting to put a wicked fast processing unit in the core along with whatever custom IO goodies they can come up with.
Too bad its not open source, as there are other wicked fast processor cores available. For example Xilinx can license you to put a PowerPC in its FPGA cores.
Imo this new "multiple cpu's per chip" is the way forward. And the huge power savings is an added bonus. One question springs to mind though, how much performance can you gain by using this technique? i mean, sooner or later you will hit the limits of say, the memory bus or the graphics bus or whatever(speaking in layman's terms obviously), especially in environments where power consumption is an issue, and huge memory banks take alot of power to keep them refreshed. Still, i welcome the development, smp type deals can make a computing experience easier to cope with during intensive use like compiling and other cpu intensive tasks.
Will wank off Linus Torvalds for fame.
Cobalt servers were originally based on ARM processors, and were for the most part really nifty. Most palmtop and cell devices also use the processors, so my question is, why don't we see more reasonable personal computers (or blades servers) based upon this architecture. People don't use the processing capacity available to them, and tuning of storage and networking often gives a better return per dollar. Somthing along the profile of the Psion Netbook or old (or new depending upon your perspective) Apple Newton (also ARM) would be very cool and useful. Give it some cellular/WiFi tech...
Incorrect.
As the subject line says, I've been running SMP desktop PCs for years. My current home PC is a dual 1GHz P-III, my wife's is a dual 850 and my Linux web/file/mail/whatever server is a dual 700 with a 12% overclock.
You can only figure on about a 40% performance increase with a dual processor desktop PC, but being able to play Quake and burn a DVD at the same time has it's advantages ;-)
As others have mentioned, multitasking is greatly enhanced - and two midrange processors are generally cheaper than one high-end processor.
Also, even though some applications aren't multithreaded, all modern desktop OS are - so you get a performance boost even running single-task applications. If you're into running Windows, Internet Explorer is multithreaded, as are all Microsoft Office applications. There's a real-world productivity boost using SMP machines.
we see things not as as they are, but as we are.
-- anais nin
As Intel is now discovering (and promoting) it has long been known that clock frequency is not a sufficient measure of performance. It matters how much processing you can do in each clock tick as well as how often your clock ticks. Naturally, the faster the clock ticks, the less processing you can do per clock tick.
1/2 GHz quoted for this core may not sound a lot, but there are some good reasons for it:
- ARM cores use a shorter pipeline than Intel cores (in general). This requires less logic to get a good throughput of operations. Less logic means less area (less cost) and less power consumption. These are important in embedded applications (you don't want your phone to be putting out 50W and costing $200).
- These cores are synthesisable. This means that ARM will deliver a "model" of the device, and customers can translate this to a silicon layout on their own process, and they can integrate peripherals, memory etc. on the same silicon. Getting a higher clock speed requires custom logic which is hard to translate between processes. Essentially the processor has sold separately as a piece of silicon, and this means a slow off-chip interface to the rest of the system.
For a multi-threaded or multi-process application such as this core is targetted, using MP cores makes more sense than using a single high-speed core and switching between processes all the time. For one thing you save all the context switching overhead.
Owl tried to think of something wise to say, but couldn't.