Why am I seeing different RAM speeds from Command Prompt and Speccy?

[fetchmehere]

Hi I have Asus A555LF with 4GB RAM. But speed is showing different by command prompt and Speccy.
Command Prompt shows:
>wmic memorychip get BankLabel,DeviceLocator,Capacity,Speed
BankLabel Capacity DeviceLocator Speed
>BANK 0 4294967296 ChannelA-DIMM0 1600

Also Task Manager shows:
Speed 1600MHz
Slots used: 1 of 2
Form Factor: SODIMM

However, Speccy Shows:
4.00GB Single-Channel DDR3 @ 798MHz (11-11-11-28)
Also CPUZ shows:
Type: DDR3
Size:3996MB
Channel# : Single
DRAM Frequency : 787MHz
(Interestingly there is an NB Frequency which sometimes shoots upto 2025MHz.)

Can someone please explain which one is correct:800 MHz or 1600MHz?

 

[clutchc]

798MHz is approx. 800MHz. Exactly what it should show for Double Data Rate 1600 MHz memory. Memory speed is effectively doubled with DDR memory, so you actually get 1600 MHz.
I can't explain the small variance between 787 and 798 other than possibly the software calculating error.

But one application is reading the RAM clock speed, the other the effective speed.

 

[fetchmehere]

So is the RAM which is installed can go up to 1600MHz? Or it's a 800MHz RAM presently and the motherboard can support upto 1600MHz RAM (So to get 1600MHz I need to purchase a 1600 MHz RAM?)

 

[clutchc]

So is the RAM which is installed can go up to 1600MHz? Or it's a 800MHz RAM presently and the motherboard can support upto 1600MHz RAM (So to get 1600MHz I need to purchase a 1600 MHz RAM?)

No, you are fine as is. The RAM has a clock speed of 800MHz. But it's effective speed is 1600MHz because of the double data rate interface. DDR memory transfers data twice in every clock cycle. So rest assured, your memory is running at 1600 MHz.

Here is a quick explanation of how DDR works: http://www.hardwaresecrets.com/everything-you-need-to-know-about-ddr-ddr2-and-ddr3-memories/

 

[fetchmehere]

Thanks Clutchc. I am at peace now.

So is the RAM which is installed can go up to 1600MHz? Or it's a 800MHz RAM presently and the motherboard can support upto 1600MHz RAM (So to get 1600MHz I need to purchase a 1600 MHz RAM?)

No, you are fine as is. The RAM has a clock speed of 800MHz. But it's effective speed is 1600MHz because of the double data rate interface. DDR memory transfers data twice in every clock cycle. So rest assured, your memory is running at 1600 MHz.

Here is a quick explanation of how DDR works: http://www.hardwaresecrets.com/everything-you-need-to-know-about-ddr-ddr2-and-ddr3-memories/