3DMark is described as 'includes everything you need to benchmark your hardware in one app. Whether you're gaming on a smartphone, tablet, notebook, laptop, desktop, or a high-performance gaming PC, 3DMark includes a benchmark designed specifically for your type of device'. There are more than 10 alternatives to 3DMark for a variety of platforms, including Windows, Mac, Linux, Android and iPhone. The best alternative is UserBenchMark, which is free. Other great apps like 3DMark are UNIGINE Benchmarks (Freemium), Cinebench (Free), Furmark (Free) and Geekbench (Paid).
UserBenchmark is a free all-in-one benchmarking application. Benchmark your CPU, GPU, SSD, HDD and USB Drives then compare results with other users and see which parts you can upgrade together with the expected performance improvements. CPU benchmarks bias toward Intel.
CINEBENCH is a real-world test suite that evaluates your computer's performance capabilities. It's the perfect tool to compare CPU and graphics performance across various systems and platforms (Windows and Mac OS X). And best of all: It's completely free.