well sorry to brake your mood but cpuuserbenchmarik is shit and so is game debate, only gpuuserbenchmark is good just open cpuuserbenchmar and you will see that an i5-2500 3.3Ghz 4core 4threads is 1% better than i7-2600 3.4GHz 4core 8threads now that aint real
That "effective speed" number is just an estimate of how the processor is expected to run in most software, and since most software tends to be lightly threaded, they don't give much weight to the i7's Hyperthreading. As a result, when comparing the i5-2500 with the i7-2600, the processors are shown to offer very similar performance at most tasks, since they are both clocked similar and based on the same generation of architecture. UserBenchmark provides multiple results though, and some are more relevant than others. "Effective speed" is probably best left for comparing processor with the same core/thread count, as it doesn't really tell much about how performance will compare in more heavily-threaded workloads.
If you scroll down a bit to the "Average User Bench" section though, you can see where the processors diverge. The i7-2600 offers better performance when all 8 of its threads are being heavily utilized (MC Mixed), which is something you might see in a heavily multithreaded game like Battlefield V. Most existing games should perform fairly similar on either processor, but those extra threads will likely provide more benefit in an increasing number of games as time goes on, as well as when multitasking while gaming.
If we go back to the i5-2500 vs i7-860 comparison though, it should be pretty clear that the newer i5 offers better performance per thread, which will result in it performing better in lightly threaded workloads that tend to be more common, even if the older i7 might manage to make up the difference when all of its threads are being utilized. You can find this mirrored by reviews too, though since these are older processors released a number of years ago, you are unlikely to see any heavily-threaded games in those reviews. You'll also likely need to check reviews for the i5-2500K, which is the unlocked version of the processor most sites reviewed, but since it is clocked the same as the i5-2500, any non-overclocked results should be the same. In general, the 2500/2500K should outperform or match prior i7s in most software.