Re: Future of CPUs
Posted: Wed Mar 17, 2010 4:05 pm
Inside the CPU, doubling the width will usually add one layer of logic. That might be 10%, although it can often be hidden due to delays elsewhere (even on Pentium 4, the pipeline limit was in the adder-schedulers, not the actual adders).Owen wrote:I doubt it. Current CPUs are really close to the limits of performance working on 64-bit numbers; remember that for many operations doubling the word size doubles the time. For example, Phenom IIs overclock better in 32-bit than 64-bit mode.
Overclocking is a function of temperature and process margin. For the same chip, the physical pipeline is the same.
Intel vs. ARM will be very interesting. ARM is also ugly, in the ways that matter for designing a high-performance chip (one word: predication). The ugliness of x86 is restricted to the instruction decoder (actually, uROM) and legacy testing (knowledge base + tools).As for Intel killing ARM, I don't see that happening. You cannot make an x86 of comparable performance with a comparable silicon budget. x86 is a very ugly architecture; ARM is not perfect but a very clean one.
Revenue is irrelevant, look at profit and acres of silicon shipped (that is the metric Intel uses). I haven't looked in a while, but Intel has been shipping more silicon than the next few companies put together for a long time, and brings in $10's e9 in profit every year. Most other silicon manufacturers break even or lose money (they are supported by government subsidies).Secondly, Intel and ARM do not directly compete: ARM licenses its cores to companies which have a combined revenue ~4x Intels. Thirdly, Intel is right on the EU's anti-trust watch list, and any attempt to do anything anti-competitive against ARM (Such as the aforementioned selling at a loss) is going to land them more large fines.
It is important to note that Intel is not a computer company or design house or anything like that.
Intel takes sand and makes money.
Processor architecture, compilers, graphics and all that are just the means to the end.
Intel is one generation ahead in process technology. That makes a lot of room for integration and power consumption... other parts will get bigger as performance increases, and Intel will "polish the turd" on Atom, driving it to maximum efficiency.You have to note that the ARM cores used in phones contain lots of peripherals, from the simple (SPI & I²C/SMBus) to communicate with external devices, to the specialized (H.264 decoders), to the application specific (Wi-Fi, UMTS and GSM basebands - often on one chip!). With Intel's current Atom platform, you require at least 4 chips to do the same (CPU + Northbridge + Southbridge + Radios); with their next, they're shrinking it to 3, but still each of those chips requires more power than an ARM which can do the same.
It is easy to increase performance when your performance is low... the interesting thing will be to see how much it costs ARM to increase more, and how much better Atom gets. I wouldn't call it either way...Intel will continue to grow, but don't expect them to get into the mobile phone market. They simply cannot compete there, and they have over half of the industry competing against them.
Oh, and the performance of ARM cores is increasing faster than that of the Atom. And this from a company with 1/1000th the revenue to do R&D with.