Check for Metal capability on your Mac OS X system. 10.11 & above only!

main.m

/*
** Compile in terminal with the following line:
** clang main.m -framework Foundation -framework Metal -o TestMetal
*/

#import <Foundation/Foundation.h>
#import <Metal/Metal.h>

int main(void) {
    @autoreleasepool {
        NSArray<id<MTLDevice>> *devices = MTLCopyAllDevices();

        printf("Metal-capable devices: %d\n", (int) devices.count);

        for (id<MTLDevice> device in devices) {
            const char *name = device.name.UTF8String;

            const char *lowpower = device.isLowPower ? "yes" : "no";
            const char *headless = device.isHeadless ? "yes" : "no";

            printf(" - %s (low power: %s, headless: %s)\n", name, lowpower, headless);
        }
    }

    return 0;
}