Personal computing discussed
Moderators: renee, Flying Fox, morphine
PrecambrianRabbit wrote:I think the more interesting question is the one you set aside: why do you think ARM will become dominant over x86? (I could theorize my own list, but I'd be curious to hear someone else's.)
bdwilcox wrote:Beyond the addressing issue...
Buub wrote:bdwilcox wrote:Beyond the addressing issue...
But that's actually a rather significant change. Can you imagine trying to use 8GB of RAM in PAE mode, where each program could only access a maximum of 3GB or so, unless it was coded to do weird addressing tricks? That's what you'd have if the addressing issue hadn't been solved with x86-64.
Bombadil wrote:Buub wrote:bdwilcox wrote:Beyond the addressing issue...
But that's actually a rather significant change. Can you imagine trying to use 8GB of RAM in PAE mode, where each program could only access a maximum of 3GB or so, unless it was coded to do weird addressing tricks? That's what you'd have if the addressing issue hadn't been solved with x86-64.
People have been running programs using PAE mode for several years with no real problems. It is called OSX, and to this day it still uses a 32-bit kernel and PAE mode by default. The only problem with running more memory in x86 Windows is non-PAE compatible hardware/drivers. Microsoft just decided it was such a mess that only server versions of x86 Windows would be allowed access to more memory. x86 Windows normally runs in PAE mode anyway since it is required for the NX bit. So in x86 Windows you have the problems of PAE mode just without the benefits. Apple got around the problems by coming rather late to x86 and supporting a lot less hardware.
Bombadil wrote:People have been running programs using PAE mode for several years with no real problems. It is called OSX, and to this day it still uses a 32-bit kernel and PAE mode by default. The only problem with running more memory in x86 Windows is non-PAE compatible hardware/drivers. Microsoft just decided it was such a mess that only server versions of x86 Windows would be allowed access to more memory. x86 Windows normally runs in PAE mode anyway since it is required for the NX bit. So in x86 Windows you have the problems of PAE mode just without the benefits. Apple got around the problems by coming rather late to x86 and supporting a lot less hardware.
Meadows wrote:I'm curious myself, but people keep failing to answer the question. You keep talking about PAE and 64-bit and whatnot - when the question really was: does IA-64, as an architecture, actually offer us something more advanced than x86*?
Too much branch prediction (was that the right word?) came up as an issue where you need specialised, predictable applications to really get good performance, but other than that, no responses so far. Instead people are talking about whether x86 is "good enough" and drivers and OSX and... good lord Cindy what is this.
bdwilcox wrote:I think the following question is a bit moot because I believe ARM will be the dominant CPU architecture of the future, not x86. But for the CPU architecture nerds in the audience, here is my purely intellectual question: From a strictly architectural / technical aspect (not involving Intel's licensing finagling and politics), would we have been better off if IA64 had become the dominant architecture versus the now ubiquitous x86-64? Why? Outside of the server environment, how would IA64 be superior or inferior? Discuss.
bdwilcox wrote:Meadows wrote:I'm curious myself, but people keep failing to answer the question. You keep talking about PAE and 64-bit and whatnot - when the question really was: does IA-64, as an architecture, actually offer us something more advanced than x86*?
Too much branch prediction (was that the right word?) came up as an issue where you need specialised, predictable applications to really get good performance, but other than that, no responses so far. Instead people are talking about whether x86 is "good enough" and drivers and OSX and... good lord Cindy what is this.
Yes, exactly. 64-bit addressing is a moot point because both x86-64 and IA64 solve the problem. I'm more interested if there is some technical benefit IA64 would have graced us with if it had become the standard rather than x86-64. Expanded addressing is about all I've seen in difference between x86 32 and 64 bit; would IA64 have given us anything on top of the addressing issue that would have made its adoption more beneficial?
It is called OSX, and to this day it still uses a 32-bit kernel and PAE mode by default.
bdwilcox wrote:To be honest, x86-64 has been in a word, underwhelming, to me. Yes, it adds the ability to address larger amounts of memory and hard drive space, but beyond that my 64-bit CPU has just been another CPU.
anubis44 wrote:I also agree with those who are questioning the emerging orthodoxy that ARM's architecture will supersede x86 on the desktop/portable (laptop, netbook) and server. Anybody saying this must be unaware that AMD already has a 3 watt dual-core x86-64 fusion chip right now, and will have it down to <1 watt as soon as 22 nanometer production commences. This is an out-of-order, dual-core APU (integrated Radeon 5000-series graphics logic) x86-64 chip! Arm is going to have be quite a bit faster and better at the same power envelope if it is going to persuade people to give up x86 compatibility for the same functionality and price. If not, ARM will suffer the same fate on the laptop-desktop-server as Intel's IA64 did trying to compete with AMD's x86 technology.
just brew it! wrote:Yeah, IMO ARM will dominate in areas where x86 compatibility is a non-issue (pretty much anything that doesn't run desktop/server versions of Windows). But on any platform where being able to run generic Windows apps is a desirable trait, x86 will likely continue to be the platform of choice for quite some time.
mikeymike wrote:What did you expect? The only thing that would revolutionise desktop computers would be in the data storage field, like if decent SSDs suddenly had the capacity and price of today's HDDs. The processor isn't an enormous performance bottleneck, it hasn't been for a long time.
anubis44 wrote:also agree with those who are questioning the emerging orthodoxy that ARM's architecture will supersede x86 on the desktop/portable (laptop, netbook) and server. Anybody saying this must be unaware that AMD already has a 3 watt dual-core x86-64 fusion chip right now, and will have it down to <1 watt as soon as 22 nanometer production commences. This is an out-of-order, dual-core APU (integrated Radeon 5000-series graphics logic) x86-64 chip! Arm is going to have be quite a bit faster and better at the same power envelope if it is going to persuade people to give up x86 compatibility for the same functionality and price. If not, ARM will suffer the same fate on the laptop-desktop-server as Intel's IA64 did trying to compete with AMD's x86 technology