Changing ram speeds need some advice... would you kindly

[Zniff]

Hi,

 

I changed my RAM DDR4 from RAM speed 2133 to 2666. and CPU-Z shows NB frequency at 4311.6 and DRAM Frequency is at 1337

i use an i 9 9900k cpu and specifications for this cpu is supposed to handle ram speed at 2666 and i use corsair vengeance PRO ram sticks and it is 4 rma sticks. what should i be alert about when doing this?

[StephanTW]

8 minutes ago, Zniff said:

Hi,

 

I changed my RAM DDR4 from RAM speed 2133 to 2666. and CPU-Z shows NB frequency at 4311.6 and DRAM Frequency is at 1337

i use an i 9 9900k cpu and specifications for this cpu is supposed to handle ram speed at 2666 and i use corsair vengeance PRO ram sticks and it is 4 rma sticks. what should i be alert about when doing this?

what you have to remember is that CPU-Z shows dran frequency not DDR4 speed which usally is twice a cycle so your actuall ram is at 2674 which seems a bit off but makes more sense

 

for example my DDR4 is running at 2133 but it shows 1066 but at the bottom the command rate is 2T so 2 times 1066 is 2132

[Zniff]

Is there anything i should be aware of when running higher ram speeds.

[StephanTW]

1 minute ago, Zniff said:

Is there anything i should be aware of when running higher ram speeds.

if it wasn't the 2666 isnt the native ram speed i would highly suggest a overnight memtest run to ensure it is stable other then that, if memtest returns errors a small bump of 0.05 or 0,1 V on the ram may make it stable.
but if it passes all you would have is a potentially faster pc and there shouldn't be any other issues

[-rascal-]

30 minutes ago, Zniff said:

Hi,

 

I changed my RAM DDR4 from RAM speed 2133 to 2666. and CPU-Z shows NB frequency at 4311.6 and DRAM Frequency is at 1337

i use an i 9 9900k cpu and specifications for this cpu is supposed to handle ram speed at 2666 and i use corsair vengeance PRO ram sticks and it is 4 rma sticks. what should i be alert about when doing this?

 

Your RAM is running at the correct frequency.

The EFFECTIVE memory speed is DDR4-2666 (2666 MHz), while the ACTUAL operating frequency is ~1333.333.. MHz.

 

This is because RAM is Double Data Rate (DDR), and it operates on BOTH the rising and falling edge of each clock cycle.

 

 

24 minutes ago, StephanTW said:

what you have to remember is that CPU-Z shows dran frequency not DDR4 speed which usally is twice a cycle so your actuall ram is at 2674 which seems a bit off but makes more sense

 

for example my DDR4 is running at 2133 but it shows 1066 but at the bottom the command rate is 2T so 2 times 1066 is 2132

 

Command Rate is the delay in clock cycles.

Nothing to do with the frequency of RAM.

1T = 1 full clock cycle delay

2T = 2 full clock cycle delays

 

"Command rate - is the delay (in clock cycles) between when chip select is asserted (i.e. the RAM is selected) and commands (i.e. Activate Row) can be issued to the RAM. Typical values are 1T (one clock cycle) and 2T (two clock cycles)."