Guess what kids, people use the GPU for encoding too these days, so I also tasked Handbrake with using QuickSync to encode the same workload on all three chips. The gap beween Skylake Core i7-6700K and Haswell Core i7-4790K opens up even more, as this test relies on the GPU and its QuickSync capabilities. But check out the big brain on Brett: That's right, 5th-gen Broadwell Core i7-5775C and its massive embedded DRAM cache pulls dead even with Skylake. Who's laughing now, 6th-gen core?
Fritz Chessbenchmark uses a real-world chess engine to compute how fast each CPU handles chess move calculations. Each unit is compared to the performance of a single 1GHz Pentium III. That means a modern CPU would be 35 times faster than a 1GHz PIII. The results show a dead tie between the Skylake and Haswell CPUs. Because the Haswell runs 200MHz faster, the Skylake chip is actually a tiny bit faster, assuming all things were even. More on this later.
I use WinRar's built-in benchmark mode to measure performance for compression and decompression loads on a CPU. Skylake again comes out on top, thanks to its more efficient CPU cores. It likely gets a nice boost from DDR4/2666, too. Compressing and decompressing has long been said to lean heavily on memory bandwidth, besides being compute-intense. WinRar 5.21 confirms that, too, as the Broadwell Core i7-5775C muscles past the Haswell and Skylake parts by a huge margin. This isn't the same for all compression tests. WinZip's built-in test actually gave me results where the Skylake pulled basically dead-even with the Haswell chip, while Broadwell, despite its large cache, landed in third place.
Sisoft Sandra Bandwidth
How much actual memory bandwidth advantage does the DDR4/2666 Skylake have over the DDR3/1600 systems? To find out, I ran Sisoft Sandra's synthetic memory bandwidth benchmark, which puts Skylake and DDR4 clearly ahead.
Sure, you're saying I could even the odds by running higher-clocked RAM in the Haswell and Broadwell systems. Maybe DDR3/3100 RAM and DDR4/3200? To see if that holds water, I checked pricing on high-clock DDR4 and DDR3 at Newegg.com. While 16GB of Corsair DDR4/3200 cost $400, the same-capacity Corsair RAM at DDR3/3100 is $1,200. It's not just Corsair, either: Other vendors are also charging a premium for high-overlocked DDR3. If you want high-clocked RAM, DDR4 just makes more sense.
Sisoft Sandra Cache Bandwidth
The world still doesn't really know much about what's making Skylake, um, tock, but cache bandwidth appears worlds better. I used Sisoft Sandra cache bandwidth test to see where the cache stacks up. Haswell's cache is poking along at 128GBps, while Skylake is blazing along at 173GBps.
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