Detecting Graphics Hardware using Objective-C

Recently, I encountered an issue with a specific graphics card and as a fix, I wanted my application to detect the Graphics Hardware and proceed accordingly. While I was searching on the web, I couldn't find much about solving the problem but I somehow managed to a collect bits and pieces and come up with the solution. So, in this post I am going to discuss the approaches which came to my mind to solve the problem, and the approach used by me.

Approaches:

1. Forking a new process and using exec() family of methods to execute the system command system_profiler SPDisplays and fetching the graphics information.

2. Second approach is almost similar to the first one, the only difference is that instead of using fork to
create a new process, we use NSTask to execute system_profiler .

3. The third approach is to use IOKit. Below is the code which can be used to get the model of the graphics card:

- (void)displayGraphicsInfo

{

    // Get dictionary of all the PCI Devicces

    CFMutableDictionaryRef matchDict = IOServiceMatching("IOPCIDevice");

    

    // Create an iterator

    io_iterator_t iterator;

    

    if (IOServiceGetMatchingServices(kIOMasterPortDefault,matchDict,

                                     &iterator) == kIOReturnSuccess)

    {

        // Iterator for devices found

        io_registry_entry_t regEntry;

        

        while ((regEntry = IOIteratorNext(iterator))) {

            // Put this services object into a dictionary object.

            CFMutableDictionaryRef serviceDictionary;

            if (IORegistryEntryCreateCFProperties(regEntry,

                                                  &serviceDictionary,

                                                  kCFAllocatorDefault,

                                                  kNilOptions) != kIOReturnSuccess)

            {

                // Service dictionary creation failed.

                IOObjectRelease(regEntry);

                continue;

            }

            const void *GPUModel = CFDictionaryGetValue(serviceDictionary, @"model");

            

            if (GPUModel != nil) {

                if (CFGetTypeID(GPUModel) == CFDataGetTypeID()) {

                    // Create a string from the CFDataRef.

                    NSString *modelName = [[NSString alloc] initWithData:

                                           (NSData *)GPUModel encoding:NSASCIIStringEncoding];

                    

                    NSLog(@"GPU Model: %@", modelName);

                    [modelName release];

                }

            }

            // Release the dictionary

            CFRelease(serviceDictionary);

            // Release the serviceObject

            IOObjectRelease(regEntry);

        }

        // Release the iterator

        IOObjectRelease(iterator);

    }

}

The approach which I have used is the 3rd approach. The drawbacks of 1st and 2nd approaches are that they are considerably slow as compared to the 3rd approach.

Source: The credit of the above solution goes to the author of *Coder Blog, Mike Piatek-Jimenez and the original post can be found here.