AMD Kaveri APU Features GDDR5/DDR4? Good read.

[Pemalite]

ethomaz said:

dahuman said:
Yew 128bit bus? Not much performance improvement from that if you think about it, but would be great for ultra-thin devices though. It'd be better if it's dual channel, then we'd be looking at 256bit bus and that'd actually make a pretty big difference.

Using GDDR5 or DDR4? It is a big boost DDR3 even using triple or quad-channel.

You can expect bandwidth over 80GB/s with 128bits easy.

You can achieve over 80GB/s with DDR3 already, you just need Quad-Channel DDR3 2600mhz or higher Ram to achieve it. :P

DDR4 won't be that much better than high-end DDR3 when it launches (It's supposedly launching at 2400mhz speeds), especially compared to those Samsung modules that can clock to 3ghz.
Over time however, it should have much bigger legs, much like DDR3 compared with DDR2.
The big benefit that DDR4 will bring initially will be power consumption, which is a massive boon for mobile devices.

ethomaz said:

AMD is right... DDR3 is already old and now it is starting to become expensive.

GDDR5 (and DDR4 after launch) will be even more cheaper when the mass production for APU, console and GPUs started.

And remember the "latency" is more related to the memory controller than the memory itself... the memory controller in GPU that have a high latency and not the GDDR5.

It's both that effects latency.
http://en.wikipedia.org/wiki/CAS_latency

However, Memory Manufacturers set the clock rates, latencies and such for the memory in the Rams SPD (EEPROM), the computer's memory controller should recognise it and apply it.
Usually though they follow the JEDEC standard.
If the motherboard/memory controller doesn't recognise the settings, it will default to a standard 1333mhz speed and accompanying timings.

http://en.wikipedia.org/wiki/Serial_presence_detect
http://en.wikipedia.org/wiki/EEPROM

Edit: Personally I can't wait for DDR4 and Haswell-E, Haswell-E should bring with it a good 20-30% performance improvement per clock over Sandy-Bridge-E  and throw another 2 cores at the performance problem, which to me makes it worth upgrading from my 3930K finally.
But, it ain't going to be cheap. :( #Firstworldproblems