1600MHz shows 800MHz

[haripriyaaithal]

I have a HP laptop which I purchased a year ago. It has 8 GB of single ddr3 ram in one slot and another slot is empty. According to specification, the frequency of ram should be 1600MHz but when I use software like CPU-Z and Speccy it shows 800MHz. Does that mean 1600MHz is for 2 slots (2x800 MHz)? or if I put another 8 GB ram with 1600MHz frequency will I get a better performance?

x 

[cj09beira]

that is normal, ddr means double data rate, your real speed is the double of the value you get :-)

[TheRandomness]

DDR = Double Data Rate. 800*2 = 1600. 

[haripriyaaithal]

2 minutes ago, cj09beira said:

that is normal, ddr means double data rate, your real speed is the double of the value you get :-)

 

2 minutes ago, TheRandomness said:

DDR = Double Data Rate. 800*2 = 1600. 

I want to add another 8 GB ram, then I have to purchase a RAM which has a frequency of 800 MHz right?

[Mr.Meerkat]

1 minute ago, haripriyaaithal said:

 

I want to add another 8 GB ram, then I have to purchase a RAM which has a frequency of 800 MHz right?

Nope, 1600MHz  

[TheRandomness]

1 minute ago, haripriyaaithal said:

 

I want to add another 8 GB ram, then I have to purchase a RAM which has a frequency of 800 MHz right?

For best compatibility, yes. (1600MHz*)

[cj09beira]

no you will need a 1600mhz stick, 

[MorganO]

1 minute ago, haripriyaaithal said:

 

I want to add another 8 GB ram, then I have to purchase a RAM which has a frequency of 800 MHz right?

no you'll need 1600 

[cj09beira]

Just now, TheRandomness said:

For best compatibility, yes. 

wrong

[TheRandomness]

Just now, cj09beira said:

wrong

Didn't read the sentence properly. 

[haripriyaaithal]

I'm confused. Which one should I buy 800MHz or 1600MHz?

[TheRandomness]

2 minutes ago, haripriyaaithal said:

I'm confused. Which one should I buy 800MHz or 1600MHz?

You cannot buy 800MHz DDR3 (they don't sell it at such a low speed). Also, all speeds are doubled for the purpose of it looks better, so you'd need to buy 1600MHz. 

[haripriyaaithal]

Ok, then even if I purchase a 1600MHz frequency ram and install, software like cpu-z tells that it is 800MHz right?

[manikyath]

in essence, ram speeds are marketing fluff, because a 1600MHz stick actually runs at 800MHz.

 

cpu-z shows the actual speed the stick is running at (800MHz), the box in the store shows the "preceived" speed that double data rate (DDR) gives you (1600MHz).

 

so yes, you need to buy a 1600MHz stick, and when you plug that in, you'll see it's also running at 800MHz

 

an easy sanity check is this: they dont make "800MHz" DDR3

[haripriyaaithal]

Thanks everyone

[typographie]

1 hour ago, haripriyaaithal said:

Ok, then even if I purchase a 1600MHz frequency ram and install, software like cpu-z tells that it is 800MHz right?

Yes. CPU-Z displays the frequency of your memory before the DDR multiplier is taken into account. My DDR4-3000 shows up as 1500 MHz in CPU-Z.

 

If you buy more RAM, you should try to match the specifications as closely as possible. Yours is DDR3-1600. CPU-Z will continue to say it's 800 MHz after you add more, that's not a problem.

[Apache Protocol]

on your cpu z on spd tab you can see what model and frequency of ram you have. much easier