PS4 8gb GDDR5, a huge waste of fast memory?

It is not so much common sense as impossible because you cannot buy GDDR5 as a consumer. Even if memory manufacturers were to make GDDR5 memory sticks like they do DDR3 memory sticks it would need to be on a different sized DIMM and that would require motherboard manufacturers to produce motherboards that support the GDDR5 DIMM standard and it would also require a CPU/APU manufacturer to produce a chip with a memory controller that can talk to GDDR5. AMD were going to do this with Kaveri but the market is too small for it to be profitable for motherboard and memory manufacturers and without them onboard it is a non starter.

If Sony wanted to cut corners to save money they would have stuck with 4GB of GDDR5 rather than up it to 8GB. They could have used a 12 CU GPU like the Xbox 1 which would have reduce the die size of the chips and lowered the cooling requirements. The PS4 has been designed with a specific sale price in mind and it appears the engineers have done an excellent job of optimising the hardware for that price point.

If you want whole system benchmarks then look a BF4, AC4 etc

AC4 - Eurogamer "It's a rock-solid 30fps on PlayStation 4 at 1080p, while the Xbox One maintains a similar performance level at its reduced 900p resolution, with just one or two little hiccups."

BF4 - Eurogamer "Hard evidence of the PS4's frame-rate lead for the retail release of Battlefield 4 - even with its 50 per cent increase in resolution it can typically command a 10fps+ advantage during our stress-tests. However, both versions do have their pitfalls."

I could go on but there is little point as you have no clue what you are talking about.

@btk2k2: them are benchmarks for launch titles yes but then you have to include time you got to work with the whole system and you and I know x1 system wasn't finalized until late August and AMD catalysis drives didn't come out until November and drivers to take advange of the embedded RAM this month so to me them are not really benchmarks and I wish yall really stop trying to say that its a hassle to put gddr5 in PC if they want to THEY MAKE TO RULES AND THEN SHOVE THE SHIT TO YOU that means if they though if was MORE EFFICIENT OR BETTER THAN WHAT THEY ARE USING NOW it would change that's why THEY DID PUT GDDR5 in GPUs because in was better for the TASK GDDR5 is NOT BETTER OR MORE EFFICIENT FOR THE CPU. folks Im not trying to argue with you I have lived on this earth long enough and at a job everyday where they make these decisions we are talking about right now THEY tell you that you have to go through the loops for the GDDR5 for system ram because if you say anything NEGATIVE you are stepping on someone in the industry foot or may burn a bridge or two and you don't want to do that in any industry.

We all totally believe your personal stories