Question Different RAM speed in CPU-Z, on the sticker on the RAM modules and in the BIOS

[DanielThommen]

I wanted to upgrade my PC as it felt slow and laggish. So I checked and researched and put in 4 sticks of 4GB of DDR3 1333MHz (my motherboard accepts max 16GB and has 4 slots, I tried 2 x 8GB, that did not work, so I sent it back and got 4 x 4GB instead).

However,...
- CPU-Z shows: 16 GBytes with DRAM frequency 399.0 MHz
- BIOS shows: 16384 MB - DDR3/800 MHz - Dual Channel
- Stickers on the RAM modules show 4GB - 1333MHz
- Task Manager (under "Memory") shows 1333 MHz DIMM (right now, in use: 5.0 GB, available: 10.7 GB)

So the 16 GB is correct everywhere.
However, the frequency is not... Anywhere from 399 MHz to 1333 MHGz. I know that, because they're DUAL, the 399 MHz is kind of only half, so per cycle 399MHz (x2 = ~800MHz. Would explain the BIOS reading of 800 MHz per stick. But they should be 1333MHz, not 800MHz...

I am using Channel A with 2 sticks and channel B with 2 sticks, so my MOBO has 4 slots, 2 slots per channel, and I have 4 of the same DDR3 sticks in each slot, hence using both channels (A&B) with two 4GB each. All sticks are the same brand, the same manufacturer, the same speed (1333MHz) and put in at the same time with the PC off and power cable out, then restart and here we are.

The PC seems a bit faster than with the 8GB I had before, but not a bunch. And the MHz issue is bothering me...

Please help, what am I reading wrong?

Thanks for any help!

 

[Aeacus]

But they should be 1333MHz, not 800MHz...

MoBo make and model is?

RAM does not automatically set itself to the highest frequency. That, you have to do from BIOS, by enabling XMP. That is, IF the XMP holds and RAM is stable. If not, you're stuck with 800/1066 Mhz (whatever is stable).

All sticks are the same brand, the same manufacturer, the same speed (1333MHz) and put in at the same time with the PC off and power cable out,

But did all 4x DIMMs came in one, sealed package? Or did you buy them separately? E.g 2x 4GB + 2x 4GB? Or 4 times 4GB (e.g individual DIMMs)?