Few questions regarding ram on first build

[dgriffs]

I will be building my system later today. I have a gigabyte GA-970-d3 motherboard. I will be putting a phenom II x4 955 cpu until I upgrade in the future to BD. My ram -
http://www.newegg.com/Product/Product.aspx?Item=N82E16820104221 - is rated 1600hz. The system should automatically downclock it to 1333hz right? Also, the ram voltage is 1.65v but ive heard people say that the default is 1.5v. Will I have to manually change this in the bios?

 

[jaquith]

GA-970A-D3 AM3+ the default for Memory Clock is x6.66 or 1333 MHz, but the default DRAM Voltage is 1.50v. The default 'SPD' DRAM Voltage, as with all DDR3, is 1.50v and yes the KHX1600C9AD3B1K2/4G has a 'SPD' {JEDEC} with 1.50v and probably XMP-1600 with 1.65v listed in CPU-z; see -> http://www.valueram.com/datasheets/KHX1600C9AD3B1K2_4G.pdf

I always manually set my RAM but it's not required.

 

[wintermint]

My gigabyte makes my voltage go crazy on auto. I do suggest you to manually set your voltage for your RAM and also check CPU.

 

[dgriffs]

So you guys are saying I should manually set the ram to 1333hz at 1.65v?

 

[jaquith]

Hmm...No if you only want them to run at DDR3 1333 MHz then use DRAM Voltage -> 1.50v, but IF you want to run them at DDR3 1600 MHz then Yes DRAM Voltage -> 1.65v.

RAM: 1600 MHz 9-9-9-27-2T @ 1.65v
RAM: 1333 MHz 9-9-9-27-2T @ 1.50v

BIOS:
Set Memory Clock -> 8 {8 x 200MHz FSB = 1600 MHz}
DRAM Voltage control -> 1.65v
DDR3 Timing Items -> Manual/Enter
* 1T/2T Command Timing -> 2 ; optional
CAS# latency -> 9
RAS to CAS R/W Delay -> 9
Row Precharge Time -> 9
Minimum RAS Active Time -> 27

Save Exit = Yes

 

[dgriffs]

Oh ok thank you very much. I've learnt a lot these past few days.

 

[dgriffs]

Best answer selected by dgriffs.

 

[jaquith]

The RAM is running at {669.7 * 2 ; Double Data Rate} 1339.4 MHz ; the FSB bus varies. So your RAM is running at DDR3 1333 MHz aka 'SPD' the tRAS is a little fast 24 vs 27 and the Command Rate is 1T which is 'typical' for defaults.

You need to look in the BIOS to 'see' what the DRAM Voltage is running at -- my guess it's going to be 1.50v.

edit: I see no reason not to run the RAM at 1600 MHz, but it's your rig. The differences with the same IC is negligible <1~2%.

CPU-z

 

[dgriffs]

Thanks again! I hope I didn't waste too much of your time.