hardware

I am writing a diagnosis program (like everest, but simpler) and I need to know how fast a HardDrive is. I wanna know things such as: 1 - Bytes per second (read) 2 - Bytes per second (write) 3 - S.M.A.R.T data I guess I can use WMI to query such thing, but i have no idea how. It does not matter if I need to buy a component or get a opensource one. I also know that Windows Perfmoon is able to do that, but I cannot use it. Rafael to obtain the S.M.A.R.T data you can use the WMI or the Windows API. using the WMI the WMI classes to obtain S.M.A.R.T data are MSStorageDriver_ATAPISmartData

This may not be considered to be directly programming related but I am at a loss to know where else to ask. I have tried looking at a variety of websites but so far Google has not been my friend. I am having trouble finding out whether I need to write my own device driver for the various windows/linux/mac platforms that the device I am developing may be connected to, or whether the functionality is provided by the standard drivers. My device is a USB CDC (communications device) that appears as a COM: port. It also includes a battery charger that will, once the device has been enumerated

I am looking for affordable solutions that generate true random numbers. I have found LavaRnd , which is a cryptographically sound random number generator. Does anybody has experience in this field and/or knows about other solutions? PS: IMHO the SO question True random number generator did not really cover this EDIT : My curiosity is more of academic nature. I don't want to know about PRNGs that are good enough for practical applications. I know they exist and that they will do. Of course, generating true random numbers will require hardware devices. That's why I tagged this with hardware .

Taking Peter Norvig's advice , I am pondering on the question: How much time does it take to fetch one word from memory, with and without a cache miss? (Assume standard hardware and architecture. To simplify calculations assume 1Ghz clock) Seems like Norvig answers this himself : execute typical instruction 1/1,000,000,000 sec = 1 nanosec fetch from L1 cache memory 0.5 nanosec branch misprediction 5 nanosec fetch from L2 cache memory 7 nanosec Mutex lock/unlock 25 nanosec fetch from main memory 100 nanosec send 2K bytes over 1Gbps network 20,000 nanosec read 1MB sequentially from memory 250

Does the Intel Xeon Phi coprocessor , to be usable as parallel platform, require a license of the Intel Composer XE compiler, or are there alternative compilers? There are a few options I can list here to use/get the Intel compiler...gcc, as you know, is not equipped to vectorize code for this platform. There is a non-commercial license of the Intel compiler for Linux* that provides the same Intel Xeon Phi coprocessor enabled Intel Development tools as a commercial/eval/academic license assuming the requesting individual fulfills the licensing requirements. http://software.intel.com/en-us/non

I understand what it means to access memory such that it is aligned but I don’t understand why this is necessary. For instance, why can I access a single byte from an address 0x…1 but I cannot access a half word (two bytes) from the same address. Again, I understand that if you have an address A and an object of size s that the access is aligned if A mod s = 0 . But I just don’t understand why this is important at the hardware level. Hardware is complex; this is a simplified explanation. A typical modern computer might have a 32-bit data bus. This means that any fetch that the CPU needs to do