RAM freqency question...

[somecanadianguy]

I recently had to clear CMOS and now notice that in BIOS my memory frequency is behaving differently.
The last OC I tested was 166bclk x 21 and RAM multi @ 8 for 1328MHz.
Now when I choose the 8x multi I see 1333Mhz displayed in BIOS.
Anyone know what's going on?

[somecanadianguy]

If I boot @ 166bclk x 21 and RAM multi @ 8 with 1333MHz showing in BIOS instead of 1328 will it be ok?
Anyone know why it's not showing 1328Mhz?

[MpG]

I wouldn't worry about it. There's a chance that the 166Mhz is actually 166.6Mhz, which would give you 1333. Some program (BIOS or otherwise) will round things off, others will try to be as precise as possible, which may account for the difference. Regardless, it's not something that should be a problem.

[somecanadianguy]

Thanks, MpG...
It booted up fine with 1333Mhz showing in BIOS.
Cpu-z shows it @ 664 (1328Mhz).

[Chris]

I have a similar question. my i7 is at 190x20. Ram multi is at 8x. So ram freq is at 1520 which is correct in BIOS. In CPUZ, it has FSB/Ram of 2.8. I am not used to intel (only oc experience in AMD), so please explain where this 2.8 comes from. TIA

[MpG]

The reason CPU-Z is showing 2:8 is because pretty much all marketing these days lists effective DDR3 (Dual Data Rate) speeds, which are twice the actual speeds. So even though your BIOS may say it's running the memory at 1520MHz, what you're really got is 760MHz memory, with an effective speed of 1520MHz.

In other words, it's all the same thing, but CPU-Z is technically more precise.

[Chris]

Thanks, but how is 2.8 calculated? Where do I find FSB value since dram is 760 or 1520. Does it mean FSB is 760*2.8=2128?

[MpG]

Just to be clear, it's 2:8 (ratio), not 2.8 (number). As you said, you chose the 8x multi for your memory (i.e. 1:8 ratio for BCLK:RAM), CPU-Z is simply re-stating that, using the memory's real frequency, instead of it's effective frequency.

The i7 doesn't have a FSB like the older systems. In your CPU-Z window, you'll see the "QPI Link" heading on the "CPU" tab, and on the "Memory" tab, you'll see a "NB Frequency" heading, which is your Uncore speed. Both have their own multipliers (which can be set in the BIOS), and are based on the BCLK. For all intents and purposes, they're the two closest things to the older FSB setup.

[Chris]

Many thanks. Now, I am onto overclocking my ram.