the 1.5 ghz kabini was 4% faster than 1.5 ghz sandy in cinebench r11.5 multithreaded. ivy is also around 3 - 5% faster than sandy at same clocks. so they are on par in perf.
also you have to look at performance within a given power and die size budget. Kabini with 4 jaguar cores is extremely power efficient. read anandtech article.
http://www.anandtech.com/show/6981/...ality-of-mainstream-pcs-with-its-latest-apu/2
"I also suspect the 15W TDP is perhaps a bit conservative, total platform power consumption with all CPU cores firing never exceeded 12W (
meaning SoC power consumption is far lower, likely sub-10W)."
So Kabini with 4 Jaguar cores at 1.5 Ghz does not draw even 10w. This is with an integrated southbridge. Jaguar at 1.5 - 1.6 Ghz seems to draw 2w per core.
A Jaguar core is 3.1 sq mm.two Jaguar cores are smaller than a single ivy core which is 10 sq mm. 8 Jaguar cores are 25 sq mm. 4 ivy cores is 40 sq mm. so both on perf/sq mm and perf/watt Jaguar (1.6 ghz) is more efficient than a notebook ivy at 1.6 Ghz.
You have to understand if a PS4 SOC TDP is 100w it will rarely come close to using all of it.
There is no way a core i7 chip at 1.6 Ghz with a HD 7970m GPU can come close to the same efficiency of a single chip PS4 APU. AMD has shaved off 2 CU (128 sp) from HD 7970m for the PS4 GPU and clocked it 50 Mhz slower. Also this PS4 SOC chip will not have a PCI-E controller like the core i7 and HD 7970m have. All CPU/GPU communication is on-die. Driving signals outside the chip takes a lot of power. you can ask any electrical engineer. so without any external GPU bus , this fully integrated single chip APU is much more efficient than a core i7 ivy (1.6 ghz) with HD 7970m. AMD / Sony have chosen clocks which yield the best combination of performance and efficiency for both the GCN GPU and Jaguar based CPU.
Just the point that HD 7970m is a 100w GPU while the entire PS4 SOC is 100w should give you the idea. if you still don't believe it you can wait for anandtech's PS4 launch article where they will measure platform power consumption. :thumbsup: