YeHi@$MmZ مراقب عام منتدى أقسام الكليه ومشرف قسمى حاسبات وكورسات هندسيه
عدد المساهمات : 5020 تاريخ التسجيل : 25/06/2007 العمر : 37 الموقع : سرى رقم العضوية : 10 Upload Photos :
| موضوع: حصرياً وللمتخصصين فقط _ كل شئ عن ال intel core i7 الخميس 26 فبراير - 7:20 | |
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عدل سابقا من قبل YeHi@$MmZ في الخميس 26 فبراير - 9:03 عدل 2 مرات | |
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YeHi@$MmZ مراقب عام منتدى أقسام الكليه ومشرف قسمى حاسبات وكورسات هندسيه
عدد المساهمات : 5020 تاريخ التسجيل : 25/06/2007 العمر : 37 الموقع : سرى رقم العضوية : 10 Upload Photos :
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YeHi@$MmZ مراقب عام منتدى أقسام الكليه ومشرف قسمى حاسبات وكورسات هندسيه
عدد المساهمات : 5020 تاريخ التسجيل : 25/06/2007 العمر : 37 الموقع : سرى رقم العضوية : 10 Upload Photos :
| موضوع: رد: حصرياً وللمتخصصين فقط _ كل شئ عن ال intel core i7 الخميس 26 فبراير - 7:54 | |
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YeHi@$MmZ مراقب عام منتدى أقسام الكليه ومشرف قسمى حاسبات وكورسات هندسيه
عدد المساهمات : 5020 تاريخ التسجيل : 25/06/2007 العمر : 37 الموقع : سرى رقم العضوية : 10 Upload Photos :
| موضوع: رد: حصرياً وللمتخصصين فقط _ كل شئ عن ال intel core i7 الخميس 26 فبراير - 8:07 | |
| مجموعة من الأسئلة خاصة بال processor intel Core i7 Q. What does SSE stand for?A: Hello, Thanks for your question. It stands for Intel’s Streaming SIMD Extensions Q. Core i7 comes with chip power management feature that can take a core to zero-power mode. How does this work? What do developers need to know?A: Nehalem introduces a new circuit technique known as the “power gate transistor”. This is a large switch (transistor) that sits between a voltage source and each core. When a core is not in use (for example, when running a single threaded application, all but one core may be inactive), the power gate can be used to literally turn off a core so that it consumes no power. Q: How many applications are already enabled for Core i7?A: There is a large number (100+) applications that Intel Application Engineers have enabled for Corei7. The list is growing everyday Q: Some newer motherboards come with error-correcting memory but it appears that Core i7 does not support these features. Why not? When?A: The first Nehalem based systems are designed for performance - so ECC was not included because it negatively impacts key performance features like memory latency. There will be Corei7 platforms with ECC in the future Q: Is it better to enable for Core i7 specific instructions or should we continue to focus on threading our applications? Seems like the rewards for enabling for Core i7 is easier and faster than threading, especially with the dynamically change core clock speed.A: New instructions and threading are not mutually exclusive. How to prioritize between those two techniques is very application dependent. But, as an example, once you take advantage of the new instructions, then threading is still a viable option for additional performance gains. Q: What programming languages does the SDK support?A:The Corei7 is not really geared towards a particular programming language. Its more of a collection of documents that describe the innovations in the Core i7 - However – the SSE intrinsic’s are for C/C++ Q: I’ve read some reviews that say Core i7 is not ideal for game performance due to a smaller L2 cache. Core i7 has a very large L3 cache to compensate. What can game developer do to take advantage of this design feature?A: First, the statement that the L2 is small and bad for games is not the case. The l2 size was determined by looking at the trade-off between latency and size and deciding the optimal part. To take advantage of the L3, most developers will not have to do anything special. For developers that want to do the next level of optimization, cache blocking is always a good technique for additional performance. Q: Core i7 brings Hyper-Threading back. Why did it get removed in Core 2 Duo? Why is it back? I’ve heard that there are use cases where performance is better when it is turned off. Why? What are the issues? Shared memory access?A: Hyperthreading has been added back to NHM due to its extraordinary power efficiency. Overall, one of the key philosophies of Nehalem was to focus on power efficiency and only add performance features that are very efficient. Hyperthreading is one of the most, if not the most, power efficient feature added in NHM. Q: Where do I ask questions about enablement of applications for Core i7?A: The ISN forums are a good place to start: : [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] Intel Engineers frequent these forums daily, and can answer any questions you may have Q: Multithreaded applications running in the intel Core i7 should benefit from faster inter-core communication.But how does it work?Are Kernel synchronization objects (i.e. Event Objects, Mutexes) affected by the advantage?Or do we only benefit when sharing same variables in memory? i.e. InterlockedBitTestAndSet() for syncronization and lock-less algorithmsA: Faster inter-core communication is facilitated by the new QuickPath Interconnect (QPI) – which is a high bandwidth/low latency point to point interconnect between the cores . For memory accesses – Nehalem maintains a set of “core valid” bits per cache line in the L3. If the L1/L2 of a core may contain the cache line, then the core valid bit is set to 1. No snoops of other cores are needed if the bit is set, Nehalem can go direct to the appropriate core to retrieve the cache line. In addition, special attention was given to the synchronization primitives, so they now run much faster then previous generations. Q: When these SSE 4.2 instructions will be availabe as a part of Intel IPP? A: Great question, that I should know - but I dont. I'll find out and include it in the transcript. Q: Are these slides included in the SDK ? A: Yes, most of them come from the SDK.
Q: where is the SDK located ?The SDK is located on the Intel Software Network at: [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] Q: Intel C++ compiler's many features for vectorization are heuristic (according to manual). Are they really safe or unpredictable erros may occur? A: Is there any specifics you can share? I dont know of any unpredictable errors
Q: Does Intel Parallel Studio support Linux OS too? Should codes compile with Intel C++ compiler first before profiling with Intel Parallel Studio? A: The Intel Compiler can give you more benefits if you use it in conjuction with Parallel Studio. The compiler has many architecture specifc codegen paths, that VS does not have Q: I've got a technical question: The Core i7 processor features a Power Control Unit which allows to run each of the four i7 cores at an individual clock. Operating Systems tend to bounce threads from one core to the other due to the scheduling algorithm they use. What may happen is that you run one thread at high clock such as 3,2Ghz and some other threads run at lower clocks on the other cores. Next time slice you'll find the hard working thread on a lower clocked core, which has to ramp up to speed first. This became an issue with the Phenom I processor which has been fixed in Phenom II. Does this also affect the i7? A: This issue should not impact Nehalem based systems. Its my understanding that the CPU will only lower the clocks when the cores are not being utilized, and as such – a multi-threaded code sequence would keep each core’s frequency running high. There should be no situation where a thread is dispatched on one high and one low frequency core. Q: An additional note regarding this topic: It didn't affect the Core2 Duo processors, since those run two cores always at the same speed (FID). I don't know about the Core2 Quad though. A: Power gating is only on Nehalem. So, Core2 quad will run all cores at the same speed Q: Hyperthreading is back on the Intel Core i7. What is the expected performance improvement, assuming the application takes advantage of threads, and it's very scalable? A: Depends on the application. Generally, HT yields better performance in NHM because of better memory BW, better cache policies/sizes, and its the 3rd generation of HT - (lots of improvements over previous generations). However, we sometimes see places where the performance of HT is not optimial - applications that are highly optimized (execution units fully utilized) leave little room for a second thread to gain any performance - or applications that saturate memory bandwidth - those may not yield a high performance improvement. Generally - its around 1.3 - 1.5x Q: Sorry if I missed it, but what are some of the new energy efficiency benefits of the Core i'? A: Yes, lots. Nehalem has a "power gate" that dynamically controlls the CPU power/frequency - It will reduce the power consumption if it detects the core is unused - or boost the frequency if a single core needs it. Its our biggest "energy" feature A Q: how to use explicitly i7 intrinsics - header files, specification, IDEs, examples of computational intensive implementations using intrinsics? A: That is something I'd like to add to the SDK as well - Intrinsic samples. I'll work on this.. There is also some docs available on MSDN - [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] Q: Q: When these SSE 4.2 instructions will be available as a part of Intel IPP?A: SSE4.2 are used under the hood in IPP 6.0 | |
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YeHi@$MmZ مراقب عام منتدى أقسام الكليه ومشرف قسمى حاسبات وكورسات هندسيه
عدد المساهمات : 5020 تاريخ التسجيل : 25/06/2007 العمر : 37 الموقع : سرى رقم العضوية : 10 Upload Photos :
| موضوع: رد: حصرياً وللمتخصصين فقط _ كل شئ عن ال intel core i7 الخميس 26 فبراير - 8:13 | |
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YeHi@$MmZ مراقب عام منتدى أقسام الكليه ومشرف قسمى حاسبات وكورسات هندسيه
عدد المساهمات : 5020 تاريخ التسجيل : 25/06/2007 العمر : 37 الموقع : سرى رقم العضوية : 10 Upload Photos :
| موضوع: رد: حصرياً وللمتخصصين فقط _ كل شئ عن ال intel core i7 الخميس 26 فبراير - 9:00 | |
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YeHi@$MmZ مراقب عام منتدى أقسام الكليه ومشرف قسمى حاسبات وكورسات هندسيه
عدد المساهمات : 5020 تاريخ التسجيل : 25/06/2007 العمر : 37 الموقع : سرى رقم العضوية : 10 Upload Photos :
| موضوع: رد: حصرياً وللمتخصصين فقط _ كل شئ عن ال intel core i7 الخميس 26 فبراير - 9:08 | |
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YeHi@$MmZ مراقب عام منتدى أقسام الكليه ومشرف قسمى حاسبات وكورسات هندسيه
عدد المساهمات : 5020 تاريخ التسجيل : 25/06/2007 العمر : 37 الموقع : سرى رقم العضوية : 10 Upload Photos :
| موضوع: رد: حصرياً وللمتخصصين فقط _ كل شئ عن ال intel core i7 الخميس 26 فبراير - 9:16 | |
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YeHi@$MmZ مراقب عام منتدى أقسام الكليه ومشرف قسمى حاسبات وكورسات هندسيه
عدد المساهمات : 5020 تاريخ التسجيل : 25/06/2007 العمر : 37 الموقع : سرى رقم العضوية : 10 Upload Photos :
| موضوع: رد: حصرياً وللمتخصصين فقط _ كل شئ عن ال intel core i7 الخميس 26 فبراير - 9:19 | |
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YeHi@$MmZ مراقب عام منتدى أقسام الكليه ومشرف قسمى حاسبات وكورسات هندسيه
عدد المساهمات : 5020 تاريخ التسجيل : 25/06/2007 العمر : 37 الموقع : سرى رقم العضوية : 10 Upload Photos :
| موضوع: رد: حصرياً وللمتخصصين فقط _ كل شئ عن ال intel core i7 الخميس 26 فبراير - 9:27 | |
| ال AMD نازلة بقوى ضد انتل _ مع العلم ان الاركيتشكر الأساسى بتاع ال AMD أصلا هو بتاع انتل لا نه يسمى based-IA-86 اى يقوم على بروسيسور intel-8086 نازلة حالياً بروسيسور 940 AMD Phenom II X4 $224Intel Core i7 940$564وضع موقع Anandtech مقارنة بوضعية CrossFireX للمعالجات التالية :I7 920 و Q9550 و Phenom2 X4 940وإليكم الأجهزة المستخدمة :نتائج الإختبار : | |
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