蘋(píng)果公司最新發(fā)表的 iPhone 5S即將上市。蘋(píng)果為這款新版iPhone 手機(jī)采用了64位元的處理器架構(gòu)，使其成為首款64位元的智能手機(jī)。但問(wèn)題是，智能手機(jī)搭載64位元的存儲(chǔ)器定址能力究竟能帶來(lái)多大的性能進(jìn)展？我懷疑這個(gè)問(wèn)題的答案可能是：差別不大。
當(dāng)ARM發(fā)布其V8架構(gòu)，跨入64位元核心領(lǐng)域，最大的好處就是擴(kuò)展了存儲(chǔ)器定址范圍，特別是針對(duì)服務(wù)器應(yīng)用來(lái)說(shuō)，其軟件堆迭幾乎完全都是基于64位元的定址存儲(chǔ)器空間。
ARM與其十多家SoC合作伙伴正為該架構(gòu)應(yīng)用推動(dòng)一項(xiàng)新計(jì)劃，預(yù)計(jì)在2014年就能看到最初的成果。不過(guò)，截至目前為止，英特爾在低功耗服務(wù)器領(lǐng)域仍占據(jù)主導(dǎo)地位。
至于移動(dòng)設(shè)備方面呢？目前似乎還沒(méi)有針對(duì)64位元開(kāi)發(fā)的軟件。以當(dāng)今32位元的主流系統(tǒng)來(lái)看，我們甚至離4GB主存儲(chǔ)器的限制還有一段距離。因此，目前在移動(dòng)設(shè)備上導(dǎo)入64位元的迫切性其實(shí)并不大。
根據(jù)The Linley Group公司分析師Kevin Krewell以及Real World Tech公司分析師David Kanter表示，他們并不看好iPhone 5S中采用64位元A7處理器能為用戶帶來(lái)什么價(jià)值。它純粹就是搶先為未來(lái)的生態(tài)系統(tǒng)揭開(kāi)序幕罷了。不過(guò)，Kanter指出，移動(dòng)設(shè)備采用Gb級(jí)以上的主存儲(chǔ)器，能夠在簡(jiǎn)化虛擬存儲(chǔ)器作業(yè)方面帶來(lái)一些性能方面的優(yōu)勢(shì)。
我的意思并不是說(shuō)智能手機(jī)永遠(yuǎn)不需要4GB以上的存儲(chǔ)器。更貼切的問(wèn)法應(yīng)該是：用這么大的存儲(chǔ)器能帶來(lái)什么進(jìn)展？
蘋(píng)果在為其新款M7傳感控制器的傳感器融合API開(kāi)啟一扇門(mén)時(shí)，也應(yīng)該試著解決這個(gè)問(wèn)題。三星先前為其最新款的Galaxy S采用了英特爾的芯片以及具備各種附加功能的傳感器。而今，蘋(píng)果也必須為其 iPhone認(rèn)真思考能提供什么樣的差異化與先進(jìn)性能。
我從幾年前開(kāi)始就不再戴手表了，對(duì)于新興的醫(yī)療保健與健身設(shè)備也沒(méi)什么興趣。但我知道，有一天還是會(huì)出現(xiàn)一些有趣的小玩意兒。
只是我懷疑沒(méi)有人真的知道該怎么做──智能手機(jī)搭載64位元ROM與生物識(shí)別技術(shù)，這是多么吸引人的架構(gòu)??！是蘋(píng)果公司如今正為此開(kāi)啟了一扇門(mén)，也掌握到了眼前的絕佳機(jī)會(huì)。但就像iPhone制造商一樣，我也很好奇蘋(píng)果究竟打算怎么做？
本文授權(quán)編譯自EE Times，版權(quán)所有，謝絕轉(zhuǎn)載
編譯：Susan Hong
參考原文：Apple Begs the 64-Bit Question，by Rick Merritt, SiliconValley Bureau Chief
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Apple's iPhone 5S, arriving within days, begs the question of what can you do with 64-bit memory addressability in a smartphone. I suspect the answer is, "Not much."
When ARM announced its V8 architecture for a 64-bit core the handwriting was on the wall. This was all about servers where the software stack is pretty much entirely based on 64-bit address spaces.
ARM and as many as a dozen of its SoC partners are gearing up an interesting initiative here that will bear its first fruits in 2014. So far, Intel still has the lead in low-power servers.
But mobile? There is no 64-bit software here yet. We are not approaching the 4 Gbyte main memory limit of today's 32-bit systems.
Analysts I talked to, such as Kevin Krewell of The Linley Group and David Kanter of Real World Tech, said they don't expect to see any user value in a 64-bit A7 chip in the iPhone 5S. This is all about plowing the field for a future ecosystem. However Kanter noted there could be some performance advantages for simplifying virtual memory operations in devices at or above a Gbyte of main memory.
Far be it from me to be the Luddite who says smartphones will never need more than 4 GBytes of memory. A better question is: What could they do with that much memory?
Apple took a stab at that question when it also opened the door to a sensor fusion API riding on top of its new M7 sensor controller. Samsung had a jump on Intel with all the sensor bells and whistles in its latest Galaxy S phones. Now, Apple is calling the iPhone faithful to think different about what it could deliver.
I stopped wearing watches years ago and have no interest in the new health and fitness devices popping up. But I don't doubt something interesting could emerge there someday.
I suspect no one really knows what to do -- that's compelling -- with a smartphone that sports 64-bit memory spaces and biometrics, including Apple. The Cupertino company is just opening a door and seeing what passes through it. Like the iPhone maker, I'm curious to hear your thoughts, too.
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• 高通：走自己的路，讓別家拼核去吧
• 蘋(píng)果Touch ID是曇花，還是轉(zhuǎn)折點(diǎn)？
• [圖文報(bào)道]蘋(píng)果發(fā)布iPhone 5S及5C，中國(guó)入首發(fā)名單v0Zesmc
責(zé)編：Quentin
