processor

I have a quad core system with third party application that once in a while spins several processes (always the same executable but several instances of it) and takes 100% of CPU time. I also have a couple of web services running on the same box (IIS and third party). The problem with the all cores being busy is that it makes this third party web server to timeout (IIS works fine though, just slower than usual). I have no control over third party web server, it's a part of the bigger product and has to be operational. So, I tried to play with processor affinity (via SysInternals Process

I am looking for things like reordering of code that could even break the code in the case of a multiple processor. Wikipedia has a fairly comprehensive list of optimization techniques here . The most important one would be memory access reordering. Absent memory fences or serializing instructions, the processor is free to reorder memory accesses. Some processor architectures have restrictions on how much they can reorder; Alpha is known for being the weakest (i.e., the one which can reorder the most). A very good treatment of the subject can be found in the Linux kernel source documentation,

I have a loop written in C++ which is executed for each element of a big integer array. Inside the loop, I mask some bits of the integer and then find the min and max values. I heard that if I use SSE instructions for these operations it will run much faster compared to a normal loop written using bitwise AND , and if-else conditions. My question is should I go for these SSE instructions? Also, what happens if my code runs on a different processor? Will it still work or these instructions are processor specific? SSE instructions are processor specific. You can look up which processor supports

Well looks too simple a question to be asked but i asked after going through few ppts on both. Both methods increase instruction throughput. And Superscaling almost always makes use of pipelining as well. Superscaling has more than one execution unit and so does pipelining or am I wrong here? Jed Smith Superscalar design involves the processor being able to issue multiple instructions in a single clock, with redundant facilities to execute an instruction. We're talking about within a single core, mind you -- multicore processing is different. Pipelining divides an instruction into steps, and

I am studying Intel Protected Mode. I found that Call Gate, Interrupt Gate, Trap Gate are almost the same. In fact, besides that Call Gate has the fields for parameter counter, and that these 3 gates have different type fields, they are identical in all other fields. As to their functions, they are all used to transfer code control into some procedure within some code segment. I am wondering, since these 3 gates all contain the information needed for the call across privilege boundaries. Why do we need 3 kinds of them? Isn't 1 just good enough? Thanks for your time and response. Update 1 A

I need to measure function execution time in nanoseconds. Now I want to understand if my computer can do that and what is the precision of measurement. There was a suggestion to use QueryPerformanceFrequency() to obtain the HPET's frequency and 1/hpetFrequency is the atomic time that can be measured. Is this right? I mean if my cpu frequency is 3.33 GH, even 1GHz that one clock duration is one nanoseconds. Doesn't it mean that I can measure by nanoseconds? For measuring time CPU or HPET's frequency is essential and why? You cannot measure to 1 nanosecond, you cannot measure to 10 nanosconds

Quick Question . for MPI implementation of my code ,i am getting a huge difference in both. I know MPI_Wtime is the real time elapsed by each processor and clock() gives a rough idea of the expected time . Do anyone wants to add some assertion ? The clock function is utterly useless. It measures cpu time, not real time/wall time, and moreover it has the following serious issues: On most implementations, the resolution is extremely bad, for example, 1/100 of a second. CLOCKS_PER_SECOND is not the resolution, just the scale. With typical values of CLOCKS_PER_SECOND (Unix standards require it to