Memory Speeds and compatibility with gigabyte mobo

[ivyfield]

Hello, recently made a new build. Setup is as follows

i52500k
gigabyte z68a d3h b3 mobo
G.SKILL Sniper Series DDR3 1600MHz (PC3-12800) 8GB (2 x 4GB) Dual Channel Kit (F3-12800CL9D-8GBSR)

I have a few concerns that I would like some assistance with please.

First issue : The ram is not listed in the mobo compatibility chart for some reason. Sounds like a popular brand. Please check the chart here in the pdf file : http://download.gigabyte.us/FileList/Memory/mb_memory_ga-z68a-d3h-b3.pdf

The computer reads it as 8Gigs so I am wondering if this is ok?

Second issue is when I use CPU-Z utility, it only shows the DRAM frequency speed to be in the 668 Mhz only whereas the ram is 1600Mhz. I suppose the Dual channel is setup properly as it states Dual Channel. Have a look at the screenshot.
Should I be getting 1600Mhz or is this normal?

Thanks

 

[GhislainG]

The Memory tab shows how much memory is installed. The SPD tab will show 4GB per module. For DDR (Double Data Rate) RAM, the frequency has to be multiplied by 2. Therefore your RAM runs at 668.6MHz x 2. You need to set the speed manually to run them at 1600MHz.

 

[ivyfield]

Ok, so right now it's running at 668x2= 1336 Mhz

And how do I set it manually and how come it's not there by default?

 

[Leaps-from-Shadows]

The CPU only supports 1333 memory by default. Technically, any speed over that is overclocking. You have to go into the BIOS and either enable XMP (which will set the memory to full speed automatically) or set the memory to 1600 manually.

 

[ivyfield]

thanks, edited in bios by enabling XMP. that was the only option available to up the speed. by the way, is this safe since you mentioned it was technically overclocking. this mobo can handle 1600 MHz and above.

 

[Leaps-from-Shadows]

It is safe as long as the RAM voltage stays near 1.5v. As it goes higher, there is a risk of damaging the memory controller in the CPU.