Quote Originally Posted by efikkan View Post
Memory timings matters very little for most benchmarks, nothing for practical use. The reason for this is the fact that no program writes to RAM and then immediately after reads it back in the next few CPU instructions. And if so, it would be in CPU cache, so it would not matter any way.

People keep complaining these kinds of tests are run without DDR3-1866, but that does normally not matter. In general the improvements will be less than 2%, sometimes none at all. You could actually run the memory at 1333 MHz and it would still not hurt too much. The exception is the APUs, which are a bit more sensitive to memory bandwidth.

Do you actually know what XMP is? XMP would not affect performance at all, it's just stored recommended settings embedded in the flash on the memory chip. The user still has to select it in the BIOS menu, and there is nothing preventing the user from running the same settings on an AMD board. "AMD Performance kit" is just marketing bullshit, any module following specs will do. And for your information, many SB/IB boards actually defaults to running DDR3-1333 even as CPU and Memory support more, so this should be an disadvantage for Intel!
I know that memory can affect AMD FX-8150 CPU. For instance, gaming under windows you would lost up to a 8% performance if you run memory at 1333 MHz instead of at stock speeds



And the performance lost would be larger in more memory intensive tasks.

Moreover, how many users will be overclocking the FX chip @ 4.8 but underclocking the ram? Memory @ 2133 seems a more adequate timing and then differences would be a bit larger.

As you say, the APUs are much more sensitive to memory bandwidth. I read reports where the gain in performance is of up to 20% by using faster memory under windows. I know AMD chips usually run faster under linux. That is why I asked about what memory is being used in phoronix tests. This is important info (at least for me) which is lacking.

So far as I know AMD mobos support XMP via emulation. Enthusiasts users say me that the best results are obtained with AMD optimized RAM. I do not know more about this issue, and this is why asked to test some AMP profile.