GTX580: 1.025VID: 950/1900/2300: stock cooler: guaranteed?!?

[donmarkoni]

Here you are the impact of overclocking GDDR5 over 4200Mhz, impact near to zero:

4200Mhz
http://3dmark.com/3dm11/984389

4300Mhz
http://3dmark.com/3dm11/984436

4400Mhz
http://3dmark.com/3dm11/984475

And you are making assumption based on 850MHz GPU testing?

You should reevaluate your conclusions based on this:

P7358 --- GTX580@1000/2000 --- 980X@4610 --- Sector 5 2250@2000/7-7-7-20-1T --- R3E --- donmarkoni

P7570 --- GTX580@1000/2400 --- 980X@4610 --- Sector 5 2250@2000/7-7-7-20-1T --- R3E --- donmarkoni