cpu

问题 I'm developing an app that polls RS232 to I2C converter, to which i have an i2c device connected, that has to be polled in realtime, meaning constantly :D As soon as response comes i reissue the command again... my code: lock (_locker) { try { _serialPort.DiscardInBuffer(); _serialPort.Write(sendArray, 0, sendArray.Length); _serialPort.ReadFixed(headerArray, headerArray.Length); returnOperation = (DeviceOperation)((int)headerArray[1] << 8 | (int)headerArray[3]); DataToReceive = headerArray[5]

问题 I am looking for a safe way to detect whether the current GPU belongs to the current high end profile (such as Motorola's Atrix or Galaxy s2) so I can, in run-time, enable some more sophisticated visual effects in my game. Has anyone successfully done anything similar? I though about detecting dual-core CPU, which would usually come with a good GPU, but I don't have enough devices to test if it is going to work OK on most situations. 回答1: If those "more sophisticated visual effects" require

问题 I'm building Cassandra 3x m1.large cluster on Amazon EC2. I've used DataStax Auto-Clustering AMI 2.5.1-pv, with Cassandra DataStax Community version 2.2.0-1. When doing write benchmarks, on 'production' data, it seems that cluster can handle around 3k to 5k write requests per second, without read load. Nearly all the time nodes do: Compaction of system.hints Compaction of mykeyspace.mybigtable Compaction of mybigtable index However, what worries me is the low CPU usage. All of the 3 nodes

问题 Following answer about Benchmarking - How to count number of instructions sent to CPU to find consumed MIPS suggest that: perf stat ./my_program on Linux will use CPU performance counters to record how many instructions it ran, and how many core clock cycles it took. (And how much CPU time it used, and will calculate MIPS for you). An example generates following output which does not contain calculated MIPS information. Performance counter stats for './hello.py': 1452.607792 task-clock (msec)

问题 I'm in the process of creating a personal monitoring program for system performance, and I'm having issues figuring out how C# retrieves CPU and GPU Temperature information. I already have the program retrieve the CPU Load and Frequency information(as well as various other things) through PerformanceCounter, but I haven't been able to find the Instance, Object,and Counter variables for CPU temp. Also, I need to be able to get the temperature of more than one GPU, as I have two. What do I do?

问题 I wondered what sort of operations can CPU handle/perform while a memory operation is in progress by a DMA-controller of a device, to increase the level of concurrency? And if the CPU cache/registers is empty, how another instruction can be fetched without interleaving DMA in progress Thx 回答1: It general, on big 1 hardware, the CPU can do more or less anything while a DMA is in progress. In general, it simply continues with normal execution of running processes or kernel tasks under the

问题 I'm very beginner in assembly language and trying to understand how these all work. My question may seem very dumb but anyway, it's not quite clear to me. Consider the following simple program: section .text global _start _start: mov eax, [text] mov [val], eax mov ecx, val mov eax, 4 mov edx, 7 mov ebx, 1 int 0x80 mov eax, 1 int 0x80 segment .bss val resb 2 segment .data text db "Th" len equ $- text Here we update values in registers and print it out with system call. But I'm wondering what

问题 I found an intel document which states memory barriers are required when string (not std::string , but assembly string instructions) are used, to prevent them being re-ordered by the CPU. However, are memory barriers also required when two threads (on two different cores) are accessing the same memory? The scenario I had in mind is where one of the CPUs which doesn't "own" the cache line writes to this memory and the core writes to its store buffer (as opposed to its cache). A memory barrier

问题 From open resources I can conclude that microcode is approximately something that can be executed directly by CPU and is responsible for implementing instruction codes. Also Wikipedia indicates that every execution of instruction code would go through a fetch-decode-execute instruction cycle. However, I cannot find any references explaining how microcode execution is done during this three-phase cycle. So my question is, what's the relationship of microcode execution and instruction cycle?

问题 I have read different type of virtualization on Wikipedia but my question is that how CPU act in each case? For example what will happen to CPU during software vs hardware virtualization? I mean in software virtualization if I increase number of VMs cpu load also increases in hardware virtualization if I increase number of VMs cpu load again increases so what is the difference between these two situation? 回答1: It's not clear what you're exactly asking but hardware supported virtualization is